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[Do Not Merge] Release 1.12 (#10292)

Browse Source 
* Update docs for fields allowed at root of CRD schema (#9973)

* add plugin docs and examples (#10053)

* docs update to promote TaintNodesByCondition to beta (#9626)

* HPA Specificity Improvements (#8757)

Updated the HPA docs to reference the `autoscaling/v2beta2` API version,
and added documentation about the new fields.

* adjust docs for pod ready++ (#10049)

* Remove --cadvisor-port - has been deprecated since v1.10 (#10023)

Change-Id: Id2a685473a243aef492a98ff450759f39e362557

* Add Documentation for Snapshot Feature (#9948)

* Add documentation for snapshot feature

* Update volume-snapshots.md

* Add dry-run to api-concepts (#10033)

* kubeadm-init: Update the offline support section (#10062)

The update includes the following things (in mind with Kubernetes 1.12):

- Remove the 1.8 image versions
- Add the 1.10 image versions that were missing until now
- Include a comment for the missing arch suffixes in 1.12

Signed-off-by: Rostislav M. Georgiev <rostislavg@vmware.com>

* Say bye to `DynamicProvisioningScheduling` (#10157)

The mentioned feature gate is now collapsed into `VolumeScheduling`.

xref: kubernetes/kubernetes#67432

* Update ResourceQuota per PriorityClass state for 1.12 (#10229)

* TokenRequest and TokenRequestProjection now beta (#10161)

xref: kubernetes/kubernetes#67349

* Change feature state for kms provider to beta. (#10230)

KMS Provider will be graduating to beta in v1.12, reflecting this change on the website.

* coredns default (#10200)

* Promote ShareProcessNamespace to beta in docs (#9996)

* Add CoreDNS details to DNS Debug docs (#10201)

* add coredns details

* address nits, add query logging section

* Update docs with topology aware dynamic provisioning (#9939)

* Document topology aware volume binding feature

* update for readability

* Update storage-classes.md

* comma splice

* don't abbreviate

* HPA Algorithm Information Improvements (#9780)

* Update HPA docs with more algorithm details

The HPA docs pointed to an out-of-date document for information on the
algorithm details, which users were finding confusing.  This sticks a
section on the algorithm in the HPA docs instead, documenting both
general behavior and corner cases.

* Add glossary info, HPA docs on quantities

People often ask about the quantity notation when working with the
metrics APIs, so this adds a glossary entry on quantities (since they're
used elsewhere in the system), and a short explantation in the HPA walkthough.

* Information about HPA readiness and stabilization

This adds information about the new changes to HPA readiness and
stabilization from kubernetes/features#591, and other minor changes that
landed in Kubernetes 1.12.

* Update horizontal-pod-autoscale.md

* Audit 1.12 doc (#9953)

* audit 1.12 document

* remove legacy audit feature

https://github.com/kubernetes/kubernetes/pull/65862

* update feature gate doc

* MountPropagation is now GA (#10090)

* RuntimeClass documentation (#10102)

* RuntimeClass documentation

* Update runtime-class.md

* Add documentation for Scheduler performance tuning (#10048)

* Add documentation for Scheduler performance tuning

* Update scheduler-perf-tuning.md

* TTL controller for cleaning up finished resources (#10064)

* TTL controller for cleaning up finished resources

* Address comments

* Update ttlafterfinished.md

* Bump quota configuration api version (#10217)

* Incremental update from master (#10278)

* fix invalid href of cloud controller manager (#10240)

* fix invalid yaml format (#10238)

* update storage-limits doc with Azure disk part (#10224)

update storage-limits doc with Azure disk part

fix comments

* Update kubelet-config-file.md (#10222)

Update link to KubeletConfiguration struct.

* fix a trivial misspelling (#10244)

* Fix cassandra-statefulset.yaml indent level (#10243)

* Mention minimum etcd versions (#10208)

Source: https://groups.google.com/d/msg/kubernetes-dev/jMPA4JzKiY4/HIx2ugvLBAAJ

* fix 404 error (#10250)

* Small verb tweak (#10190)

Present participle, ftw.

* Add AnchorJS logic for header links (#10155)

* Add AnchorJS JavaScript

* Remove existing inpage_heading logic

* Remove underline from anchor tags

* Use single icon and add touch visibility

* Use paragraph link icon for AnchorJS

* Update Sass to use code formatting in docsContent headers

* Update header size coverage to H3-H6

* fix broken link in kubefed.md (#10254)

* Update the version numbers for the X-Remote-Extra- and Impersonate-Extra- key fixes (#9827)

The fix was cherry picked into 1.11.3, 1.10.7, and 1.9.11:

https://github.com/kubernetes/kubernetes/pull/67162
https://github.com/kubernetes/kubernetes/pull/67163
https://github.com/kubernetes/kubernetes/pull/67164

* fix typo (#10168)

* fix typo

* addressing comments.

* Update setup-ha-etcd-with-kubeadm.md

* fix typos (#10252)

* fix description of contribute guide (#10253)

* describe truncate feature about advanced audit (#10236)

* describe truncate feature about advanced audit

* Update audit.md

* docs update to promote ScheduleDaemonSetPods to beta (#9923)

* Dynamic volume limit updates for 1.12 (#10211)

* add a placeholder commit

* Update docs for csi volume limits

* Update storage-limits.md

* Add "MayRunAs" value among other GroupStrategies (#9888)

* Add CoreDNS details to the customize DNS doc (#10228)

* Add CoreDNS details to the customize DNS doc

Rewrite the document to include more details about CoreDNS, since it's now the default from v1.12

* Address comments

* Improve doc wording

* Fix link

* Update dns-custom-nameservers.md

* Update dns-custom-nameservers.md

* Fix secrets docs in 1.12 branch (#10056)

* Fix secrets docs

* Update secret.md

* Revert CoreDNS Docs (#10319)

* Revert "Add CoreDNS details to DNS Debug docs (#10201)"

This reverts commit 462817a674.

* Revert "Add CoreDNS details to the customize DNS doc (#10228)"

This reverts commit e7319eeb8c.

* Revert "coredns default (#10200)"

This reverts commit 698e93b441.

* Add CRI installation instructions page

Added cri-installation page with CRI installation instructions
Referenced it from kubeadm-init and install-kubeadm pages.

* kubeadm: update API types documentation for 1.12 (#10283)

v1alpha2 -> v1alpha3
MasterConfiguration -> [new-api-types]

* TokenRequest feature documentation (#10295)

* AdvancedAuditing is now GA (#10156)

xref: kubernetes/kubernetes#65862

`AdvancedAuditing` feature is GA in 1.12. This PR adjusts the related
docs.

* update runtime-class.md (#10332)

* update runtime-class.md

* Update runtime-class.md

* Document cross-authorizer permissions for creating RBAC roles (#10015)

* Document cross-authorizer permissions for creating RBAC roles

* Update rbac.md

* kubeadm: update authored content for 1.12 (reference docs and cluster creation) (#10348)

* kubeadm: update authored content in reference docs for 1.12

* kubeadm: add time frame in create-cluster-kubeadm for 1.12

* add AllowedProcMountTypes and ProcMountType to docs (#9911)

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

* kubeadm: add new command line reference (#10306)

Add:
- placeholder files
- include place holder files
- include "renew" sub command
- add missing tabs for "alpha phase kubelet"

* Documenting SCTP support in Kubernetes (#10279)

* Documenting SCTP support in Kubernetes Service, Endpoint, NetworkPolicy and Pod

* Updates based on comments on the PR

* kubectl expose update with SCTP support

* Updated according to comments in the PR

* Revert "kubectl expose update with SCTP support"

This reverts commit 0d5a1e6720a012390cf100c83e16b4a8c0782356.

* TLS Bootstrap and Server Cert Rotation feature documentation (#10232)

* TokenRequest feature documentation

* line wrapping to make review not insane

* update content for GA without major refactor

* Update kubelet-tls-bootstrapping.md

* Add clarifications for volume snapshots (#10296)

* Update kubadm ha installation for 1.12 (#10264)

* Update kubadm ha installation for 1.12

Signed-off-by: Chuck Ha <ha.chuck@gmail.com>

* update stable version

Signed-off-by: Chuck Ha <ha.chuck@gmail.com>

* Update stacked control plane for v1.12 (#2)

* use v1alpha3

Signed-off-by: Chuck Ha <ha.chuck@gmail.com>

* more v1alpha3 (#4)

* updates

Signed-off-by: Chuck Ha <ha.chuck@gmail.com>

* Document how to run in-tree cloud providers with kubeadm (#10357)

Change-Id: Iab6b996a830503d74a6eb0c507c5f8ca7a39235b

* kubeadm reference doc for release 1.12 (#10359)

* Revert "Revert "Add CoreDNS details to DNS Debug docs (#10201)""

This reverts commit bb30f4d1fcd6fba2fe6190778ead99f8010033b7.

* Revert "Revert "Add CoreDNS details to the customize DNS doc (#10228)""

This reverts commit bc23d45c09d7b83cac130fe22a0bd91e72435862.

* Revert "Revert "coredns default (#10200)""

This reverts commit 7f4350d6ab7fc554ee53126d3875e845d2e43d1f.

* add missing instruction for ha guide (#10374)

Signed-off-by: Chuck Ha <ha.chuck@gmail.com>

* kubeadm - Ha upgrade updates (#10340)

* Update HA upgrade docs

* Adds external etcd HA upgrade guide

Signed-off-by: Chuck Ha <ha.chuck@gmail.com>

* copyedit

* more edits

* add runasgroup in psp (#10076)

* update KubeletPluginsWatcher feature gate (#10205)

* generated 1.12 docs

* Building Multi-arch images with Manifests (#10379)

In 1.12, a variety of images used in a typical kubernetes installation
have started to using manifests to better support environments with arm
or ppc64le architectures. For example all images used with kubeadm by
default have manifests, another would be all the tests in the
conformance test suite. Here we capture the best practices for everyone
to start using manifests in their own workflows.

Change-Id: I5ba4c5fe55ffc9486a8251760f3352be4f2e1494

* Upgrade docs for v1.12 (#10344)

* generated assets and docs

* remove 1.7

* update 1.12

* update plugin documentation under docs>tasks>extend-kubectl (#10259)

* update plugin documentation under docs>tasks>extend-kubectl

* Update kubectl-plugins.md
This commit is contained in:
Jim Angel
2018-09-27 18:41:39 -05:00
committed by k8s-ci-robot
parent 593b631522
commit 786d314da5
178 changed files with 9054 additions and 2728 deletions
Download Patch File Download Diff File Expand all files Collapse all files
content/en/docs/tasks/administer-cluster/dns-custom-nameservers.md
+139 -33
View File
@@ -28,28 +28,19 @@ DNS is a built-in Kubernetes service launched automatically
using the addon manager
[cluster add-on](http://releases.k8s.io/{{< param "githubbranch" >}}/cluster/addons/README.md).
The running DNS Pod holds 3 containers:
As of Kubernetes v1.12, CoreDNS is the recommended DNS Server, replacing kube-dns. However, kube-dns may still be installed by
default with certain Kubernetes installer tools. Refer to the documentation provided by your installer to know which DNS server is installed by default.
- "`kubedns`": watches the Kubernetes master for changes
in Services and Endpoints, and maintains in-memory lookup structures to serve
DNS requests.
- "`dnsmasq`": adds DNS caching to improve performance.
- "`sidecar`": provides a single health check endpoint
to perform healthchecks for `dnsmasq` and `kubedns`.
The DNS Pod is exposed as a Kubernetes Service with a static IP.
The kubelet passes DNS to each container with the `--cluster-dns=<dns-service-ip>`
flag.
The CoreDNS Deployment is exposed as a Kubernetes Service with a static IP.
Both the CoreDNS and kube-dns Service are named `kube-dns` in the `metadata.name` field. This is done so that there is greater interoperability with workloads that relied on the legacy `kube-dns` Service name to resolve addresses internal to the cluster. It abstracts away the implementation detail of which DNS provider is running behind that common endpoint.
The kubelet passes DNS to each container with the `--cluster-dns=<dns-service-ip>` flag.
DNS names also need domains. You configure the local domain in the kubelet
with the flag `--cluster-domain=<default-local-domain>`.
The Kubernetes cluster DNS server is based on the
[SkyDNS](https://github.com/skynetservices/skydns) library. It supports forward
lookups (A records), service lookups (SRV records), and reverse IP address
lookups (PTR records).
## Inheriting DNS from the node
The DNS server supports forward lookups (A records), port lookups (SRV records), reverse IP address lookups (PTR records),
and more. For more information see [DNS for Services and Pods] (/docs/concepts/services-networking/dns-pod-service/).
If a Pod's `dnsPolicy` is set to "`default`", it inherits the name resolution
configuration from the node that the Pod runs on. The Pod's DNS resolution
@@ -61,7 +52,130 @@ use the kubelet's `--resolv-conf` flag. Set this flag to "" to prevent Pods fro
inheriting DNS. Set it to a valid file path to specify a file other than
`/etc/resolv.conf` for DNS inheritance.
## Configure stub-domain and upstream DNS servers
## CoreDNS
CoreDNS is a general-purpose authoritative DNS server that can serve as cluster DNS, complying with the [dns specifications]
(https://github.com/kubernetes/dns/blob/master/docs/specification.md).
### CoreDNS ConfigMap options
CoreDNS is a DNS server that is modular and pluggable, and each plugin adds new functionality to CoreDNS.
This can be configured by maintaining a [Corefile](https://coredns.io/2017/07/23/corefile-explained/), which is the CoreDNS
configuration file. A cluster administrator can modify the ConfigMap for the CoreDNS Corefile to change how service discovery works.
In Kubernetes, CoreDNS is installed with the following default Corefile configuration.
```yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: coredns
namespace: kube-system
Corefile: |
.:53 {
errors
health
kubernetes cluster.local in-addr.arpa ip6.arpa {
pods insecure
upstream
fallthrough in-addr.arpa ip6.arpa
}
prometheus :9153
proxy . /etc/resolv.conf
cache 30
loop
reload
loadbalance
}
```
The Corefile configuration includes the following [plugins](https://coredns.io/plugins/) of CoreDNS:
* [errors](https://coredns.io/plugins/errors/): Errors are logged to stdout.
* [health](https://coredns.io/plugins/health/): Health of CoreDNS is reported to http://localhost:8080/health.
* [kubernetes](https://coredns.io/plugins/kubernetes/): CoreDNS will reply to DNS queries based on IP of the services and pods of Kubernetes. You can find more details [here](https://coredns.io/plugins/kubernetes/).
> The `pods insecure` option is provided for backward compatibility with kube-dns. You can use the `pod verified` option, which returns an A record only if there exists a pod in same namespace with matching IP. The `pods disabled` option can be used if you don't use pod records.
> `Upstream` is used for resolving services that point to external hosts (External Services).
* [prometheus](https://coredns.io/plugins/prometheus/): Metrics of CoreDNS are available at http://localhost:9153/metrics in [Prometheus](https://prometheus.io/) format.
* [proxy](https://coredns.io/plugins/proxy/): Any queries that are not within the cluster domain of Kubernetes will be forwarded to predefined resolvers (/etc/resolv.conf).
* [cache](https://coredns.io/plugins/cache/): This enables a frontend cache.
* [loop](https://coredns.io/plugins/loop/): Detects simple forwarding loops and halts the CoreDNS process if a loop is found.
* [reload](https://coredns.io/plugins/reload): Allows automatic reload of a changed Corefile.
* [loadbalance](https://coredns.io/plugins/loadbalance): This is a round-robin DNS loadbalancer by randomizing the order of A, AAAA, and MX records in the answer.
We can modify the default behavior by modifying this configmap.
### Configuration of Stub-domain and upstream nameserver using CoreDNS
CoreDNS has the ability to configure stubdomains and upstream nameservers using the [proxy plugin](https://coredns.io/plugins/proxy/).
#### Example
If a cluster operator has a [Consul](https://www.consul.io/) domain server located at 10.150.0.1, and all Consul names have the suffix .consul.local. To configure it in CoreDNS, the cluster administrator creates the following stanza in the CoreDNS ConfigMap.
```
consul.local:53 {
errors
cache 30
proxy . 10.150.0.1
}
```
To explicitly force all non-cluster DNS lookups to go through a specific nameserver at 172.16.0.1, point the `proxy` and `upstream` to the nameserver instead of `/etc/resolv.conf`
```
proxy . 172.16.0.1
```
```
upstream 172.16.0.1
```
So, the final ConfigMap along with the default `Corefile` configuration will look like:
```yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: coredns
namespace: kube-system
Corefile: |
.:53 {
errors
health
kubernetes cluster.local in-addr.arpa ip6.arpa {
pods insecure
upstream 172.16.0.1
fallthrough in-addr.arpa ip6.arpa
}
prometheus :9153
proxy . 172.16.0.1
cache 30
loop
reload
loadbalance
}
consul.local:53 {
errors
cache 30
proxy . 10.150.0.1
}
```
In Kubernetes version 1.10 and later, kubeadm supports automatic translation of the CoreDNS ConfigMap from the kube-dns ConfigMap.
## Kube-dns
Kube-dns is now available as a optional DNS server since CoreDNS is now the default.
The running DNS Pod holds 3 containers:
- "`kubedns`": watches the Kubernetes master for changes
in Services and Endpoints, and maintains in-memory lookup structures to serve
DNS requests.
- "`dnsmasq`": adds DNS caching to improve performance.
- "`sidecar`": provides a single health check endpoint
to perform healthchecks for `dnsmasq` and `kubedns`.
### Configure stub-domain and upstream DNS servers
Cluster administrators can specify custom stub domains and upstream nameservers
by providing a ConfigMap for kube-dns (`kube-system:kube-dns`).
@@ -102,7 +216,7 @@ details about the configuration option format.
{{% capture discussion %}}
### Effects on Pods
#### Effects on Pods
Custom upstream nameservers and stub domains do not affect Pods with a
`dnsPolicy` set to "`Default`" or "`None`".
@@ -136,7 +250,7 @@ DNS queries are routed according to the following flow:
![DNS lookup flow](/docs/tasks/administer-cluster/dns-custom-nameservers/dns.png)
## ConfigMap options
### ConfigMap options
Options for the kube-dns `kube-system:kube-dns` ConfigMap:
@@ -145,9 +259,9 @@ Options for the kube-dns `kube-system:kube-dns` ConfigMap:
| `stubDomains` (optional) | A JSON map using a DNS suffix key such as “acme.local”, and a value consisting of a JSON array of DNS IPs. | The target nameserver can itself be a Kubernetes Service. For instance, you can run your own copy of dnsmasq to export custom DNS names into the ClusterDNS namespace. |
| `upstreamNameservers` (optional) | A JSON array of DNS IPs. | If specified, the values replace the nameservers taken by default from the node’s `/etc/resolv.conf`. Limits: a maximum of three upstream nameservers can be specified. |
### Examples
#### Examples
#### Example: Stub domain
##### Example: Stub domain
In this example, the user has a Consul DNS service discovery system they want to
integrate with kube-dns. The consul domain server is located at 10.150.0.1, and
@@ -169,7 +283,7 @@ Note that the cluster administrator does not want to override the node’s
upstream nameservers, so they did not specify the optional
`upstreamNameservers` field.
#### Example: Upstream nameserver
##### Example: Upstream nameserver
In this example the cluster administrator wants to explicitly force all
non-cluster DNS lookups to go through their own nameserver at 172.16.0.1.
@@ -189,17 +303,9 @@ data:
{{% /capture %}}
## Configuring CoreDNS {#config-coredns}
## CoreDNS configuration equivalent to kube-dns
You can configure [CoreDNS](https://coredns.io/) as a service discovery.
CoreDNS is available as an option in Kubernetes starting with version 1.9.
It is currently a [GA feature](https://github.com/kubernetes/community/blob/master/keps/sig-network/0010-20180314-coredns-GA-proposal.md) and is on course to be [the default](https://github.com/kubernetes/community/blob/master/keps/sig-network/0012-20180518-coredns-default-proposal.md), replacing kube-dns.
## CoreDNS ConfigMap options
CoreDNS chains plugins and can be configured by maintaining a Corefile with the ConfigMap. CoreDNS supports all the functionalities and more that is provided by kube-dns.
CoreDNS supports all the functionalities and more that is provided by kube-dns.
A ConfigMap created for kube-dns to support `StubDomains`and `upstreamNameservers` translates to the `proxy` plugin in CoreDNS.
Similarly, the `Federation` plugin translates to the `federation` plugin in CoreDNS.
@@ -276,8 +382,8 @@ In Kubernetes version 1.10 and later, kubeadm supports automatic translation of
## Migration to CoreDNS
A number of tools support the installation of CoreDNS instead of kube-dns.
To migrate from kube-dns to CoreDNS, [a detailed blog](https://coredns.io/2018/05/21/migration-from-kube-dns-to-coredns/) is available to help users adapt CoreDNS in place of kube-dns.
A cluster administrator can also migrate using [the deploy script](https://github.com/coredns/deployment/blob/master/kubernetes/deploy.sh), which will also help you translate the kube-dns configmap to the equivalent CoreDNS one.
## What's next
- [Debugging DNS Resolution](/docs/tasks/administer-cluster/dns-debugging-resolution/).
content/en/docs/tasks/administer-cluster/dns-debugging-resolution.md
+105 -11
View File
@@ -13,7 +13,7 @@ This page provides hints on diagnosing DNS problems.
{{% capture prerequisites %}}
* {{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
* Kubernetes version 1.6 and above.
* The cluster must be configured to use the `kube-dns` addon.
* The cluster must be configured to use the `coredns` (or `kube-dns`) addons.
{{% /capture %}}
{{% capture steps %}}
@@ -68,7 +68,7 @@ nameserver 10.0.0.10
options ndots:5
```
Errors such as the following indicate a problem with the kube-dns add-on or
Errors such as the following indicate a problem with the coredns/kube-dns add-on or
associated Services:
```
@@ -93,6 +93,17 @@ nslookup: can't resolve 'kubernetes.default'
Use the `kubectl get pods` command to verify that the DNS pod is running.
For CoreDNS:
```shell
kubectl get pods --namespace=kube-system -l k8s-app=kube-dns
NAME READY STATUS RESTARTS AGE
...
coredns-7b96bf9f76-5hsxb 1/1 Running 0 1h
coredns-7b96bf9f76-mvmmt 1/1 Running 0 1h
...
```
Or for kube-dns:
```shell
kubectl get pods --namespace=kube-system -l k8s-app=kube-dns
NAME READY STATUS RESTARTS AGE
@@ -107,8 +118,26 @@ have to deploy it manually.
### Check for Errors in the DNS pod
Use `kubectl logs` command to see logs for the DNS daemons.
Use `kubectl logs` command to see logs for the DNS containers.
For CoreDNS:
```shell
for p in $(kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o name); do kubectl logs --namespace=kube-system $p; done
```
Here is an example of a healthy CoreDNS log:
```
.:53
2018/08/15 14:37:17 [INFO] CoreDNS-1.2.2
2018/08/15 14:37:17 [INFO] linux/amd64, go1.10.3, 2e322f6
CoreDNS-1.2.2
linux/amd64, go1.10.3, 2e322f6
2018/08/15 14:37:17 [INFO] plugin/reload: Running configuration MD5 = 24e6c59e83ce706f07bcc82c31b1ea1c
```
For kube-dns, there are 3 sets of logs:
```shell
kubectl logs --namespace=kube-system $(kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o name | head -1) -c kubedns
@@ -117,8 +146,8 @@ kubectl logs --namespace=kube-system $(kubectl get pods --namespace=kube-system
kubectl logs --namespace=kube-system $(kubectl get pods --namespace=kube-system -l k8s-app=kube-dns -o name | head -1) -c sidecar
```
See if there is any suspicious log. Letter '`W`', '`E`', '`F`' at the beginning
represent Warning, Error and Failure. Please search for entries that have these
See if there are any suspicious error messages in the logs. In kube-dns, a '`W`', '`E`' or '`F`' at the beginning
of a line represents a Warning, Error or Failure. Please search for entries that have these
as the logging level and use
[kubernetes issues](https://github.com/kubernetes/kubernetes/issues)
to report unexpected errors.
@@ -135,6 +164,8 @@ kube-dns ClusterIP 10.0.0.10 <none> 53/UDP,53/TCP 1h
...
```
Note that the service name will be "kube-dns" for both CoreDNS and kube-dns deployments.
If you have created the service or in the case it should be created by default
but it does not appear, see
[debugging services](/docs/tasks/debug-application-cluster/debug-service/) for
@@ -158,20 +189,83 @@ For additional Kubernetes DNS examples, see the
[cluster-dns examples](https://github.com/kubernetes/examples/tree/master/staging/cluster-dns)
in the Kubernetes GitHub repository.
### Are DNS queries being received/processed?
You can verify if queries are being received by CoreDNS by adding the `log` plugin to the CoreDNS configuration (aka Corefile).
The CoreDNS Corefile is held in a ConfigMap named `coredns`. To edit it, use the command ...
```
kubectl -n kube-system edit configmap coredns
```
Then add `log` in the Corefile section per the example below.
```
apiVersion: v1
kind: ConfigMap
metadata:
name: coredns
namespace: kube-system
data:
Corefile: |
.:53 {
log
errors
health
kubernetes cluster.local in-addr.arpa ip6.arpa {
pods insecure
upstream
fallthrough in-addr.arpa ip6.arpa
}
prometheus :9153
proxy . /etc/resolv.conf
cache 30
loop
reload
loadbalance
}
```
After saving the changes, it may take up to minute or two for Kubernetes to propagate these changes to the CoreDNS pods.
Next, make some queries and view the logs per the sections above in this document. If CoreDNS pods are receiving the queries, you should see them in the logs.
Here is an example of a query in the log.
```
.:53
2018/08/15 14:37:15 [INFO] CoreDNS-1.2.0
2018/08/15 14:37:15 [INFO] linux/amd64, go1.10.3, 2e322f6
CoreDNS-1.2.0
linux/amd64, go1.10.3, 2e322f6
2018/09/07 15:29:04 [INFO] plugin/reload: Running configuration MD5 = 162475cdf272d8aa601e6fe67a6ad42f
2018/09/07 15:29:04 [INFO] Reloading complete
172.17.0.18:41675 - [07/Sep/2018:15:29:11 +0000] 59925 "A IN kubernetes.default.svc.cluster.local. udp 54 false 512" NOERROR qr,aa,rd,ra 106 0.000066649s
```
## Known issues
Kubernetes installs do not configure the nodes' resolv.conf files to use the
cluster DNS by default, because that process is inherently distro-specific.
Some Linux distributions (e.g. Ubuntu), use a local DNS resolver by default (systemd-resolved).
Systemd-resolved moves and replaces `/etc/resolv.conf` with a stub file that can cause a fatal forwarding
loop when resolving names in upstream servers. This can be fixed manually by using kubelet's `--resolv-conf` flag
to point to the correct `resolv.conf` (With `systemd-resolved`, this is `/run/systemd/resolve/resolv.conf`).
kubeadm 1.11 automatically detects `systemd-resolved`, and adjusts the kubelet flags accordingly.
Kubernetes installs do not configure the nodes' `resolv.conf` files to use the
cluster DNS by default, because that process is inherently distribution-specific.
This should probably be implemented eventually.
Linux's libc is impossibly stuck ([see this bug from
2005](https://bugzilla.redhat.com/show_bug.cgi?id=168253)) with limits of just
3 DNS `nameserver` records and 6 DNS `search` records. Kubernetes needs to
consume 1 `nameserver` record and 3 `search` records. This means that if a
3 DNS `nameserver` records and 6 DNS `search` records. Kubernetes needs to
consume 1 `nameserver` record and 3 `search` records. This means that if a
local installation already uses 3 `nameserver`s or uses more than 3 `search`es,
some of those settings will be lost. As a partial workaround, the node can run
some of those settings will be lost. As a partial workaround, the node can run
`dnsmasq` which will provide more `nameserver` entries, but not more `search`
entries. You can also use kubelet's `--resolv-conf` flag.
entries. You can also use kubelet's `--resolv-conf` flag.
If you are using Alpine version 3.3 or earlier as your base image, DNS may not
work properly owing to a known issue with Alpine.
content/en/docs/tasks/administer-cluster/dns-horizontal-autoscaling.md
+23 -20
View File
@@ -36,10 +36,10 @@ The output is similar to this:
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
...
kube-dns-autoscaler 1 1 1 1 ...
dns-autoscaler 1 1 1 1 ...
...
If you see "kube-dns-autoscaler" in the output, DNS horizontal autoscaling is
If you see "dns-autoscaler" in the output, DNS horizontal autoscaling is
already enabled, and you can skip to
[Tuning autoscaling parameters](#tuning-autoscaling-parameters).
@@ -53,10 +53,13 @@ The output is similar to this:
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
...
kube-dns 1 1 1 1 ...
coredns 2 2 2 2 ...
...
In Kubernetes versions earlier than 1.5 DNS is implemented using a
In Kubernetes versions earlier than 1.12, the DNS Deployment was called "kube-dns".
In Kubernetes versions earlier than 1.5 DNS was implemented using a
ReplicationController instead of a Deployment. So if you don't see kube-dns,
or a similar name, in the preceding output, list the ReplicationControllers in
your cluster in the kube-system namespace:
@@ -77,7 +80,7 @@ If you have a DNS Deployment, your scale target is:
Deployment/<your-deployment-name>
where <dns-deployment-name> is the name of your DNS Deployment. For example, if
your DNS Deployment name is kube-dns, your scale target is Deployment/kube-dns.
your DNS Deployment name is coredns, your scale target is Deployment/coredns.
If you have a DNS ReplicationController, your scale target is:
@@ -111,7 +114,7 @@ DNS horizontal autoscaling is now enabled.
## Tuning autoscaling parameters
Verify that the kube-dns-autoscaler ConfigMap exists:
Verify that the dns-autoscaler ConfigMap exists:
kubectl get configmap --namespace=kube-system
@@ -119,12 +122,12 @@ The output is similar to this:
NAME DATA AGE
...
kube-dns-autoscaler 1 ...
dns-autoscaler 1 ...
...
Modify the data in the ConfigMap:
kubectl edit configmap kube-dns-autoscaler --namespace=kube-system
kubectl edit configmap dns-autoscaler --namespace=kube-system
Look for this line:
@@ -151,15 +154,15 @@ There are other supported scaling patterns. For details, see
There are a few options for turning DNS horizontal autoscaling. Which option to
use depends on different conditions.
### Option 1: Scale down the kube-dns-autoscaler deployment to 0 replicas
### Option 1: Scale down the dns-autoscaler deployment to 0 replicas
This option works for all situations. Enter this command:
kubectl scale deployment --replicas=0 kube-dns-autoscaler --namespace=kube-system
kubectl scale deployment --replicas=0 dns-autoscaler --namespace=kube-system
The output is:
deployment.extensions/kube-dns-autoscaler scaled
deployment.extensions/dns-autoscaler scaled
Verify that the replica count is zero:
@@ -169,33 +172,33 @@ The output displays 0 in the DESIRED and CURRENT columns:
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
...
kube-dns-autoscaler 0 0 0 0 ...
dns-autoscaler 0 0 0 0 ...
...
### Option 2: Delete the kube-dns-autoscaler deployment
### Option 2: Delete the dns-autoscaler deployment
This option works if kube-dns-autoscaler is under your own control, which means
This option works if dns-autoscaler is under your own control, which means
no one will re-create it:
kubectl delete deployment kube-dns-autoscaler --namespace=kube-system
kubectl delete deployment dns-autoscaler --namespace=kube-system
The output is:
deployment.extensions "kube-dns-autoscaler" deleted
deployment.extensions "dns-autoscaler" deleted
### Option 3: Delete the kube-dns-autoscaler manifest file from the master node
### Option 3: Delete the dns-autoscaler manifest file from the master node
This option works if kube-dns-autoscaler is under control of the
This option works if dns-autoscaler is under control of the
[Addon Manager](https://git.k8s.io/kubernetes/cluster/addons/README.md)'s
control, and you have write access to the master node.
Sign in to the master node and delete the corresponding manifest file.
The common path for this kube-dns-autoscaler is:
The common path for this dns-autoscaler is:
/etc/kubernetes/addons/dns-horizontal-autoscaler/dns-horizontal-autoscaler.yaml
After the manifest file is deleted, the Addon Manager will delete the
kube-dns-autoscaler Deployment.
dns-autoscaler Deployment.
{{% /capture %}}
content/en/docs/tasks/administer-cluster/kms-provider.md
+1 -1
View File
@@ -16,7 +16,7 @@ This page shows how to configure a Key Management Service (KMS) provider and plu
* etcd v3 or later is required
{{< feature-state for_k8s_version="v1.10" state="alpha" >}}
{{< feature-state for_k8s_version="v1.12" state="beta" >}}
{{% /capture %}}
content/en/docs/tasks/administer-cluster/kubeadm/kubeadm-upgrade-1-12.md
+295
View File
@@ -0,0 +1,295 @@
---
reviewers:
- sig-cluster-lifecycle
title: Upgrading kubeadm clusters from v1.11 to v1.12
content_template: templates/task
---
{{% capture overview %}}
This page explains how to upgrade a Kubernetes cluster created with `kubeadm` from version 1.11.x to version 1.12.x, and from version 1.12.x to 1.12.y, where `y > x`.
{{% /capture %}}
{{% capture prerequisites %}}
- You need to have a `kubeadm` Kubernetes cluster running version 1.11.0 or later.
[Swap must be disabled][swap].
The cluster should use a static control plane and etcd pods.
- Make sure you read the [release notes](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.12.md) carefully.
- Make sure to back up any important components, such as app-level state stored in a database.
`kubeadm upgrade` does not touch your workloads, only components internal to Kubernetes, but backups are always a best practice.
[swap]: https://serverfault.com/questions/684771/best-way-to-disable-swap-in-linux
### Additional information
- All containers are restarted after upgrade, because the container spec hash value is changed.
- You can upgrade only from one minor version to the next minor version.
That is, you cannot skip versions when you upgrade.
For example, you can upgrade only from 1.10 to 1.11, not from 1.9 to 1.11.
{{% /capture %}}
{{% capture steps %}}
## Upgrade the control plane
1. On your master node, upgrade kubeadm:
{{< tabs name="k8s_install" >}}
{{% tab name="Ubuntu, Debian or HypriotOS" %}}
apt-get update
apt-get upgrade -y kubelet kubeadm
{{% /tab %}}
{{% tab name="CentOS, RHEL or Fedora" %}}
yum upgrade -y kubeadm --disableexcludes=kubernetes
{{% /tab %}}
{{< /tabs >}}
1. Verify that the download works and has the expected version:
```shell
kubeadm version
```
1. On the master node, run:
```shell
kubeadm upgrade plan
```
You should see output similar to this:
```shell
[preflight] Running pre-flight checks.
[upgrade] Making sure the cluster is healthy:
[upgrade/config] Making sure the configuration is correct:
[upgrade/config] Reading configuration from the cluster...
[upgrade/config] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[upgrade] Fetching available versions to upgrade to
[upgrade/versions] Cluster version: v1.11.3
[upgrade/versions] kubeadm version: v1.12.0
[upgrade/versions] Latest stable version: v1.11.3
[upgrade/versions] Latest version in the v1.11 series: v1.11.3
[upgrade/versions] Latest experimental version: v1.13.0-alpha.0
Components that must be upgraded manually after you have upgraded the control plane with 'kubeadm upgrade apply':
COMPONENT CURRENT AVAILABLE
Kubelet 2 x v1.11.1 v1.12.0
1 x v1.11.3 v1.12.0
Upgrade to the latest experimental version:
COMPONENT CURRENT AVAILABLE
API Server v1.11.3 v1.12.0
Controller Manager v1.11.3 v1.12.0
Scheduler v1.11.3 v1.12.0
Kube Proxy v1.11.3 v1.12.0
CoreDNS 1.1.3 1.2.2
Etcd 3.2.18 3.2.24
You can now apply the upgrade by executing the following command:
kubeadm upgrade apply v1.12.0
_____________________________________________________________________
```
This command checks that your cluster can be upgraded, and fetches the versions you can upgrade to.
1. Choose a version to upgrade to, and run the appropriate command. For example:
```shell
kubeadm upgrade apply v1.12.0
```
You should see output similar to this:
<!-- TODO: output from stable -->
```shell
[preflight] Running pre-flight checks.
[upgrade] Making sure the cluster is healthy:
[upgrade/config] Making sure the configuration is correct:
[upgrade/config] Reading configuration from the cluster...
[upgrade/config] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[upgrade/apply] Respecting the --cri-socket flag that is set with higher priority than the config file.
[upgrade/version] You have chosen to change the cluster version to "v1.12.0"
[upgrade/versions] Cluster version: v1.11.3
[upgrade/versions] kubeadm version: v1.12.0
[upgrade/confirm] Are you sure you want to proceed with the upgrade? [y/N]: y
[upgrade/prepull] Will prepull images for components [kube-apiserver kube-controller-manager kube-scheduler etcd]
[upgrade/prepull] Prepulling image for component etcd.
[upgrade/prepull] Prepulling image for component kube-apiserver.
[upgrade/prepull] Prepulling image for component kube-controller-manager.
[upgrade/prepull] Prepulling image for component kube-scheduler.
[apiclient] Found 0 Pods for label selector k8s-app=upgrade-prepull-etcd
[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-kube-apiserver
[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-kube-scheduler
[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-kube-controller-manager
[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-etcd
[upgrade/prepull] Prepulled image for component kube-apiserver.
[upgrade/prepull] Prepulled image for component kube-controller-manager.
[upgrade/prepull] Prepulled image for component kube-scheduler.
[upgrade/prepull] Prepulled image for component etcd.
[upgrade/prepull] Successfully prepulled the images for all the control plane components
[upgrade/apply] Upgrading your Static Pod-hosted control plane to version "v1.12.0"...
Static pod: kube-apiserver-ip-172-31-80-76 hash: d9b7af93990d702b3ee9a2beca93384b
Static pod: kube-controller-manager-ip-172-31-80-76 hash: 44a081fb5d26e90773ceb98b4e16fe10
Static pod: kube-scheduler-ip-172-31-80-76 hash: 009228e74aef4d7babd7968782118d5e
Static pod: etcd-ip-172-31-80-76 hash: 997fcf3d8d974c98abc14556cc02617e
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests661777755/etcd.yaml"
[upgrade/staticpods] Moved new manifest to "/etc/kubernetes/manifests/etcd.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests-2018-09-19-18-58-14/etcd.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[upgrade/staticpods] This might take a minute or longer depending on the component/version gap (timeout 5m0s
Static pod: etcd-ip-172-31-80-76 hash: 997fcf3d8d974c98abc14556cc02617e
<snip>
[apiclient] Found 1 Pods for label selector component=etcd
[upgrade/staticpods] Component "etcd" upgraded successfully!
[upgrade/etcd] Waiting for etcd to become available
[util/etcd] Waiting 0s for initial delay
[util/etcd] Attempting to see if all cluster endpoints are available 1/10
[upgrade/staticpods] Writing new Static Pod manifests to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests661777755"
[controlplane] wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests661777755/kube-apiserver.yaml"
[controlplane] wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests661777755/kube-controller-manager.yaml"
[controlplane] wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests661777755/kube-scheduler.yaml"
[upgrade/staticpods] Moved new manifest to "/etc/kubernetes/manifests/kube-apiserver.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests-2018-09-19-18-58-14/kube-apiserver.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[upgrade/staticpods] This might take a minute or longer depending on the component/version gap (timeout 5m0s
<snip>
Static pod: kube-apiserver-ip-172-31-80-76 hash: 854a5a8468f899093c6a967bb81dcfbc
[apiclient] Found 1 Pods for label selector component=kube-apiserver
[upgrade/staticpods] Component "kube-apiserver" upgraded successfully!
[upgrade/staticpods] Moved new manifest to "/etc/kubernetes/manifests/kube-controller-manager.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests-2018-09-19-18-58-14/kube-controller-manager.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[upgrade/staticpods] This might take a minute or longer depending on the component/version gap (timeout 5m0s
Static pod: kube-controller-manager-ip-172-31-80-76 hash: 44a081fb5d26e90773ceb98b4e16fe10
Static pod: kube-controller-manager-ip-172-31-80-76 hash: b651f83474ae70031d5fb2cab73bd366
[apiclient] Found 1 Pods for label selector component=kube-controller-manager
[upgrade/staticpods] Component "kube-controller-manager" upgraded successfully!
[upgrade/staticpods] Moved new manifest to "/etc/kubernetes/manifests/kube-scheduler.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests-2018-09-19-18-58-14/kube-scheduler.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[upgrade/staticpods] This might take a minute or longer depending on the component/version gap (timeout 5m0s
Static pod: kube-scheduler-ip-172-31-80-76 hash: 009228e74aef4d7babd7968782118d5e
Static pod: kube-scheduler-ip-172-31-80-76 hash: da406e5a49adfbbeb90fe2a0cf8fd8d1
[apiclient] Found 1 Pods for label selector component=kube-scheduler
[upgrade/staticpods] Component "kube-scheduler" upgraded successfully!
[uploadconfig] storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.12" in namespace kube-system with the configuration for the kubelets in the cluster
[kubelet] Downloading configuration for the kubelet from the "kubelet-config-1.12" ConfigMap in the kube-system namespace
[kubelet] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "ip-172-31-80-76" as an annotation
[bootstraptoken] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstraptoken] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstraptoken] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy
[upgrade/successful] SUCCESS! Your cluster was upgraded to "v1.12.0". Enjoy!
[upgrade/kubelet] Now that your control plane is upgraded, please proceed with upgrading your kubelets if you haven't already done so.
```
1. Manually upgrade your Software Defined Network (SDN).
Your Container Network Interface (CNI) provider may have its own upgrade instructions to follow.
Check the [addons](/docs/concepts/cluster-administration/addons/) page to
find your CNI provider and see whether additional upgrade steps are required.
## Upgrade master and node packages
1. Prepare each node for maintenance, marking it unschedulable and evicting the workloads:
```shell
kubectl drain $NODE --ignore-daemonsets
```
On the master node, you must add `--ignore-daemonsets`:
```shell
kubectl drain ip-172-31-85-18
node "ip-172-31-85-18" cordoned
error: unable to drain node "ip-172-31-85-18", aborting command...
There are pending nodes to be drained:
ip-172-31-85-18
error: DaemonSet-managed pods (use --ignore-daemonsets to ignore): calico-node-5798d, kube-proxy-thjp9
```
```
kubectl drain ip-172-31-85-18 --ignore-daemonsets
node "ip-172-31-85-18" already cordoned
WARNING: Ignoring DaemonSet-managed pods: calico-node-5798d, kube-proxy-thjp9
node "ip-172-31-85-18" drained
```
1. Upgrade the Kubernetes package version on each `$NODE` node by running the Linux package manager for your distribution:
{{< tabs name="k8s_install" >}}
{{% tab name="Ubuntu, Debian or HypriotOS" %}}
apt-get update
apt-get upgrade -y kubelet kubeadm
{{% /tab %}}
{{% tab name="CentOS, RHEL or Fedora" %}}
yum upgrade -y kubelet kubeadm --disableexcludes=kubernetes
{{% /tab %}}
{{< /tabs >}}
## Upgrade kubelet on each node
1. On each node except the master node, upgrade the kubelet config:
```shell
sudo kubeadm upgrade node config --kubelet-version $(kubelet --version | cut -d ' ' -f 2)
```
1. Restart the kubelet process:
```shell
sudo systemctl restart kubelet
```
1. Verify that the new version of the `kubelet` is running on the node:
```shell
systemctl status kubelet
```
1. Bring the node back online by marking it schedulable:
```shell
kubectl uncordon $NODE
```
1. After the kubelet is upgraded on all nodes, verify that all nodes are available again by running the following command from anywhere kubectl can access the cluster:
```shell
kubectl get nodes
```
The `STATUS` column should show `Ready` for all your nodes, and the version number should be updated.
{{% /capture %}}
## Recovering from a failure state
If `kubeadm upgrade` fails and does not roll back, for example because of an unexpected shutdown during execution, you can run `kubeadm upgrade` again.
This command is idempotent and eventually makes sure that the actual state is the desired state you declare.
To recover from a bad state, you can also run `kubeadm upgrade --force` without changing the version that your cluster is running.
## How it works
`kubeadm upgrade apply` does the following:
- Checks that your cluster is in an upgradeable state:
- The API server is reachable
- All nodes are in the `Ready` state
- The control plane is healthy
- Enforces the version skew policies.
- Makes sure the control plane images are available or available to pull to the machine.
- Upgrades the control plane components or rollbacks if any of them fails to come up.
- Applies the new `kube-dns` and `kube-proxy` manifests and enforces that all necessary RBAC rules are created.
- Creates new certificate and key files of the API server and backs up old files if they're about to expire in 180 days.
content/en/docs/tasks/administer-cluster/kubeadm/kubeadm-upgrade-1-8.md
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@@ -1,290 +0,0 @@
---
reviewers:
- pipejakob
- luxas
- roberthbailey
- jbeda
title: Upgrading kubeadm clusters from 1.7 to 1.8
content_template: templates/task
---
{{% capture overview %}}
This guide is for upgrading `kubeadm` clusters from version 1.7.x to 1.8.x, as well as 1.7.x to 1.7.y and 1.8.x to 1.8.y where `y > x`.
See also [upgrading kubeadm clusters from 1.6 to 1.7](/docs/tasks/administer-cluster/kubeadm-upgrade-1-7/) if you're on a 1.6 cluster currently.
{{% /capture %}}
{{% capture prerequisites %}}
Before proceeding:
- You need to have a functional `kubeadm` Kubernetes cluster running version 1.7.0 or higher in order to use the process described here.
- Make sure you read the [release notes](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG.md#v180-beta1) carefully.
- As `kubeadm upgrade` does not upgrade etcd make sure to back it up. You can, for example, use `etcdctl backup` to take care of this.
- Note that `kubeadm upgrade` will not touch any of your workloads, only Kubernetes-internal components. As a best-practice you should back up what's important to you. For example, any app-level state, such as a database an app might depend on (like MySQL or MongoDB) must be backed up beforehand.
Also, note that only one minor version upgrade is supported. That is, you can only upgrade from, say 1.7 to 1.8, not from 1.7 to 1.9.
{{% /capture %}}
{{% capture steps %}}
## Upgrading your control plane
You have to carry out the following steps by executing these commands on your master node:
1. Install the most recent version of `kubeadm` using `curl` like so:
{{< caution >}}
```shell
export VERSION=$(curl -sSL https://dl.k8s.io/release/stable.txt) # or manually specify a released Kubernetes version
export ARCH=amd64 # or: arm, arm64, ppc64le, s390x
curl -sSL https://dl.k8s.io/release/${VERSION}/bin/linux/${ARCH}/kubeadm > /usr/bin/kubeadm
chmod a+rx /usr/bin/kubeadm
```
**Caution:** Upgrading the `kubeadm` package on your system prior to
upgrading the control plane causes a failed upgrade. Even though
`kubeadm` is shipped in the Kubernetes repositories, it's important
to install `kubeadm` manually. The kubeadm team is working on fixing
this limitation.
{{< /caution >}}
Verify that this download of kubeadm works, and has the expected version:
```shell
kubeadm version
```
2. If this the first time you use `kubeadm upgrade`, in order to preserve the configuration for future upgrades, do:
Note that for below you will need to recall what CLI args you passed to `kubeadm init` the first time.
If you used flags, do:
```shell
kubeadm config upload from-flags [flags]
```
Where `flags` can be empty.
If you used a config file, do:
```shell
kubeadm config upload from-file --config [config]
```
Where the `config` is mandatory.
3. On the master node, run the following:
```shell
kubeadm upgrade plan
```
You should see output similar to this:
```shell
[preflight] Running pre-flight checks
[upgrade] Making sure the cluster is healthy:
[upgrade/health] Checking API Server health: Healthy
[upgrade/health] Checking Node health: All Nodes are healthy
[upgrade/health] Checking Static Pod manifests exists on disk: All manifests exist on disk
[upgrade/config] Making sure the configuration is correct:
[upgrade/config] Reading configuration from the cluster...
[upgrade/config] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[upgrade] Fetching available versions to upgrade to:
[upgrade/versions] Cluster version: v1.7.1
[upgrade/versions] kubeadm version: v1.8.0
[upgrade/versions] Latest stable version: v1.8.0
[upgrade/versions] Latest version in the v1.7 series: v1.7.6
Components that must be upgraded manually after you've upgraded the control plane with 'kubeadm upgrade apply':
COMPONENT CURRENT AVAILABLE
Kubelet 1 x v1.7.1 v1.7.6
Upgrade to the latest version in the v1.7 series:
COMPONENT CURRENT AVAILABLE
API Server v1.7.1 v1.7.6
Controller Manager v1.7.1 v1.7.6
Scheduler v1.7.1 v1.7.6
Kube Proxy v1.7.1 v1.7.6
Kube DNS 1.14.4 1.14.4
You can now apply the upgrade by executing the following command:
kubeadm upgrade apply v1.7.6
_____________________________________________________________________
Components that must be upgraded manually after you've upgraded the control plane with 'kubeadm upgrade apply':
COMPONENT CURRENT AVAILABLE
Kubelet 1 x v1.7.1 v1.8.0
Upgrade to the latest stable version:
COMPONENT CURRENT AVAILABLE
API Server v1.7.1 v1.8.0
Controller Manager v1.7.1 v1.8.0
Scheduler v1.7.1 v1.8.0
Kube Proxy v1.7.1 v1.8.0
Kube DNS 1.14.4 1.14.4
You can now apply the upgrade by executing the following command:
kubeadm upgrade apply v1.8.0
Note: Before you do can perform this upgrade, you have to update kubeadm to v1.8.0
_____________________________________________________________________
```
The `kubeadm upgrade plan` checks that your cluster is in an upgradeable state and fetches the versions available to upgrade to in an user-friendly way.
4. Pick a version to upgrade to and run, for example, `kubeadm upgrade apply` as follows:
```shell
kubeadm upgrade apply v1.8.0
```
You should see output similar to this:
```shell
[preflight] Running pre-flight checks
[upgrade] Making sure the cluster is healthy:
[upgrade/health] Checking API Server health: Healthy
[upgrade/health] Checking Node health: All Nodes are healthy
[upgrade/health] Checking Static Pod manifests exists on disk: All manifests exist on disk
[upgrade/config] Making sure the configuration is correct:
[upgrade/config] Reading configuration from the cluster...
[upgrade/config] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[upgrade/version] You have chosen to upgrade to version "v1.8.0"
[upgrade/versions] Cluster version: v1.7.1
[upgrade/versions] kubeadm version: v1.8.0
[upgrade/prepull] Will prepull images for components [kube-apiserver kube-controller-manager kube-scheduler]
[upgrade/prepull] Prepulling image for component kube-scheduler.
[upgrade/prepull] Prepulling image for component kube-apiserver.
[upgrade/prepull] Prepulling image for component kube-controller-manager.
[apiclient] Found 0 Pods for label selector k8s-app=upgrade-prepull-kube-scheduler
[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-kube-scheduler
[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-kube-apiserver
[apiclient] Found 1 Pods for label selector k8s-app=upgrade-prepull-kube-controller-manager
[upgrade/prepull] Prepulled image for component kube-apiserver.
[upgrade/prepull] Prepulled image for component kube-controller-manager.
[upgrade/prepull] Prepulled image for component kube-scheduler.
[upgrade/prepull] Successfully prepulled the images for all the control plane components
[upgrade/apply] Upgrading your Static Pod-hosted control plane to version "v1.8.0"...
[upgrade/staticpods] Writing upgraded Static Pod manifests to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests432902769"
[controlplane] Wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests432902769/kube-apiserver.yaml"
[controlplane] Wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests432902769/kube-controller-manager.yaml"
[controlplane] Wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests432902769/kube-scheduler.yaml"
[upgrade/staticpods] Moved upgraded manifest to "/etc/kubernetes/manifests/kube-apiserver.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests155856668/kube-apiserver.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[apiclient] Found 1 Pods for label selector component=kube-apiserver
[upgrade/staticpods] Component "kube-apiserver" upgraded successfully!
[upgrade/staticpods] Moved upgraded manifest to "/etc/kubernetes/manifests/kube-controller-manager.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests155856668/kube-controller-manager.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[apiclient] Found 1 Pods for label selector component=kube-controller-manager
[upgrade/staticpods] Component "kube-controller-manager" upgraded successfully!
[upgrade/staticpods] Moved upgraded manifest to "/etc/kubernetes/manifests/kube-scheduler.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests155856668/kube-scheduler.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[apiclient] Found 1 Pods for label selector component=kube-scheduler
[upgrade/staticpods] Component "kube-scheduler" upgraded successfully!
[uploadconfig] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[bootstraptoken] Configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstraptoken] Configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[addons] Applied essential addon: kube-dns
[addons] Applied essential addon: kube-proxy
[upgrade/successful] SUCCESS! Your cluster was upgraded to "v1.8.0". Enjoy!
[upgrade/kubelet] Now that your control plane is upgraded, please proceed with upgrading your kubelets in turn.
```
`kubeadm upgrade apply` does the following:
- It checks that your cluster is in an upgradeable state, that is:
- The API Server is reachable,
- All nodes are in the `Ready` state, and
- The control plane is healthy
- It enforces the version skew policies.
- It makes sure the control plane images are available or available to pull to the machine.
- It upgrades the control plane components or rollbacks if any of them fails to come up.
- It applies the new `kube-dns` and `kube-proxy` manifests and enforces that all necessary RBAC rules are created.
5. Manually upgrade your Software Defined Network (SDN).
Your Container Network Interface (CNI) provider might have its own upgrade instructions to follow now.
Check the [addons](/docs/concepts/cluster-administration/addons/) page to
find your CNI provider and see if there are additional upgrade steps
necessary.
6. Add RBAC permissions for automated certificate rotation. In the future, kubeadm will perform this step automatically:
```shell
kubectl create clusterrolebinding kubeadm:node-autoapprove-certificate-rotation --clusterrole=system:certificates.k8s.io:certificatesigningrequests:selfnodeclient --group=system:nodes
```
## Upgrading your master and node packages
For each host (referred to as `$HOST` below) in your cluster, upgrade `kubelet` by executing the following commands:
1. Prepare the host for maintenance, marking it unschedulable and evicting the workload:
```shell
kubectl drain $HOST --ignore-daemonsets
```
When running this command against the master host, this error is expected and can be safely ignored (since there are static pods running on the master):
```shell
node "master" already cordoned
error: pods not managed by ReplicationController, ReplicaSet, Job, DaemonSet or StatefulSet (use --force to override): etcd-kubeadm, kube-apiserver-kubeadm, kube-controller-manager-kubeadm, kube-scheduler-kubeadm
```
2. Upgrade the Kubernetes package versions on the `$HOST` node by using a Linux distribution-specific package manager:
If the host is running a Debian-based distro such as Ubuntu, run:
```shell
apt-get update
apt-get upgrade
```
If the host is running CentOS or the like, run:
```shell
yum update
```
Now the new version of the `kubelet` should be running on the host. Verify this using the following command on `$HOST`:
```shell
systemctl status kubelet
```
3. Bring the host back online by marking it schedulable:
```shell
kubectl uncordon $HOST
```
4. After upgrading `kubelet` on each host in your cluster, verify that all nodes are available again by executing the following (from anywhere, for example, from outside the cluster):
```shell
kubectl get nodes
```
If the `STATUS` column of the above command shows `Ready` for all of your hosts, you are done.
## Recovering from a bad state
If `kubeadm upgrade` somehow fails and fails to roll back, due to an unexpected shutdown during execution for instance,
you may run `kubeadm upgrade` again as it is idempotent and should eventually make sure the actual state is the desired state you are declaring.
You can use `kubeadm upgrade` to change a running cluster with `x.x.x --> x.x.x` with `--force`, which can be used to recover from a bad state.
{{% /capture %}}
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---
reviewers:
- pipejakob
- luxas
- roberthbailey
- jbeda
title: Upgrading/downgrading kubeadm clusters between v1.8 to v1.9
content_template: templates/task
---
{{% capture overview %}}
This guide is for upgrading `kubeadm` clusters from version 1.8.x to 1.9.x, as well as 1.8.x to 1.8.y and 1.9.x to 1.9.y where `y > x`.
See also [upgrading kubeadm clusters from 1.7 to 1.8](/docs/tasks/administer-cluster/kubeadm-upgrade-1-8/) if you're on a 1.7 cluster currently.
{{% /capture %}}
{{% capture prerequisites %}}
Before proceeding:
- You need to have a functional `kubeadm` Kubernetes cluster running version 1.8.0 or higher in order to use the process described here. Swap also needs to be disabled.
- Make sure you read the [release notes](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.9.md) carefully.
- `kubeadm upgrade` now allows you to upgrade etcd. `kubeadm upgrade` will also upgrade of etcd to 3.1.10 as part of upgrading from v1.8 to v1.9 by default. This is due to the fact that etcd 3.1.10 is the officially validated etcd version for Kubernetes v1.9. The upgrade is handled automatically by kubeadm for you.
- Note that `kubeadm upgrade` will not touch any of your workloads, only Kubernetes-internal components. As a best-practice you should back up what's important to you. For example, any app-level state, such as a database an app might depend on (like MySQL or MongoDB) must be backed up beforehand.
{{< caution >}}
**Caution:** All the containers will get restarted after the upgrade, due to container spec hash value gets changed.
{{< /caution >}}
Also, note that only one minor version upgrade is supported. For example, you can only upgrade from 1.8 to 1.9, not from 1.7 to 1.9.
{{% /capture %}}
{{% capture steps %}}
## Upgrading your control plane
Execute these commands on your master node:
1. Install the most recent version of `kubeadm` using `curl` like so:
```shell
export VERSION=$(curl -sSL https://dl.k8s.io/release/stable.txt) # or manually specify a released Kubernetes version
export ARCH=amd64 # or: arm, arm64, ppc64le, s390x
curl -sSL https://dl.k8s.io/release/${VERSION}/bin/linux/${ARCH}/kubeadm > /usr/bin/kubeadm
chmod a+rx /usr/bin/kubeadm
```
{{< caution >}}
**Caution:** Upgrading the `kubeadm` package on your system prior to upgrading the control plane causes a failed upgrade.
Even though `kubeadm` ships in the Kubernetes repositories, it's important to install `kubeadm` manually. The kubeadm
team is working on fixing this limitation.
{{< /caution >}}
Verify that this download of kubeadm works and has the expected version:
```shell
kubeadm version
```
2. On the master node, run the following:
```shell
kubeadm upgrade plan
```
You should see output similar to this:
```shell
[preflight] Running pre-flight checks
[upgrade] Making sure the cluster is healthy:
[upgrade/health] Checking API Server health: Healthy
[upgrade/health] Checking Node health: All Nodes are healthy
[upgrade/health] Checking Static Pod manifests exists on disk: All manifests exist on disk
[upgrade/config] Making sure the configuration is correct:
[upgrade/config] Reading configuration from the cluster...
[upgrade/config] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -o yaml'
[upgrade] Fetching available versions to upgrade to:
[upgrade/versions] Cluster version: v1.8.1
[upgrade/versions] kubeadm version: v1.9.0
[upgrade/versions] Latest stable version: v1.9.0
[upgrade/versions] Latest version in the v1.8 series: v1.8.6
Components that must be upgraded manually after you've upgraded the control plane with 'kubeadm upgrade apply':
COMPONENT CURRENT AVAILABLE
Kubelet 1 x v1.8.1 v1.8.6
Upgrade to the latest version in the v1.8 series:
COMPONENT CURRENT AVAILABLE
API Server v1.8.1 v1.8.6
Controller Manager v1.8.1 v1.8.6
Scheduler v1.8.1 v1.8.6
Kube Proxy v1.8.1 v1.8.6
Kube DNS 1.14.4 1.14.5
You can now apply the upgrade by executing the following command:
kubeadm upgrade apply v1.8.6
_____________________________________________________________________
Components that must be upgraded manually after you've upgraded the control plane with 'kubeadm upgrade apply':
COMPONENT CURRENT AVAILABLE
Kubelet 1 x v1.8.1 v1.9.0
Upgrade to the latest stable version:
COMPONENT CURRENT AVAILABLE
API Server v1.8.1 v1.9.0
Controller Manager v1.8.1 v1.9.0
Scheduler v1.8.1 v1.9.0
Kube Proxy v1.8.1 v1.9.0
Kube DNS 1.14.5 1.14.7
You can now apply the upgrade by executing the following command:
kubeadm upgrade apply v1.9.0
Note: Before you do can perform this upgrade, you have to update kubeadm to v1.9.0
_____________________________________________________________________
```
The `kubeadm upgrade plan` checks that your cluster is upgradeable and fetches the versions available to upgrade to in an user-friendly way.
To check CoreDNS version, include the `--feature-gates=CoreDNS=true` flag to verify the CoreDNS version which will be installed in place of kube-dns.
3. Pick a version to upgrade to and run. For example:
```shell
kubeadm upgrade apply v1.9.0
```
You should see output similar to this:
```shell
[preflight] Running pre-flight checks.
[upgrade] Making sure the cluster is healthy:
[upgrade/config] Making sure the configuration is correct:
[upgrade/config] Reading configuration from the cluster...
[upgrade/config] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml'
[upgrade/version] You have chosen to upgrade to version "v1.9.0"
[upgrade/versions] Cluster version: v1.8.1
[upgrade/versions] kubeadm version: v1.9.0
[upgrade/confirm] Are you sure you want to proceed with the upgrade? [y/N]: y
[upgrade/prepull] Will prepull images for components [kube-apiserver kube-controller-manager kube-scheduler]
[upgrade/apply] Upgrading your Static Pod-hosted control plane to version "v1.9.0"...
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests802453804/etcd.yaml"
[upgrade/staticpods] Moved upgraded manifest to "/etc/kubernetes/manifests/etcd.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests502223003/etcd.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[apiclient] Found 1 Pods for label selector component=etcd
[upgrade/staticpods] Component "etcd" upgraded successfully!
[upgrade/staticpods] Writing upgraded Static Pod manifests to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests802453804"
[controlplane] Wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests802453804/kube-apiserver.yaml"
[controlplane] Wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests802453804/kube-controller-manager.yaml"
[controlplane] Wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/tmp/kubeadm-upgraded-manifests802453804/kube-scheduler.yaml"
[upgrade/staticpods] Moved upgraded manifest to "/etc/kubernetes/manifests/kube-apiserver.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests502223003/kube-apiserver.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[apiclient] Found 1 Pods for label selector component=kube-apiserver
[upgrade/staticpods] Component "kube-apiserver" upgraded successfully!
[upgrade/staticpods] Moved upgraded manifest to "/etc/kubernetes/manifests/kube-controller-manager.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests502223003/kube-controller-manager.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[apiclient] Found 1 Pods for label selector component=kube-controller-manager
[upgrade/staticpods] Component "kube-controller-manager" upgraded successfully!
[upgrade/staticpods] Moved upgraded manifest to "/etc/kubernetes/manifests/kube-scheduler.yaml" and backed up old manifest to "/etc/kubernetes/tmp/kubeadm-backup-manifests502223003/kube-scheduler.yaml"
[upgrade/staticpods] Waiting for the kubelet to restart the component
[apiclient] Found 1 Pods for label selector component=kube-scheduler
[upgrade/staticpods] Component "kube-scheduler" upgraded successfully!
[uploadconfig] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[bootstraptoken] Configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstraptoken] Configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstraptoken] Configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[addons] Applied essential addon: kube-dns
[addons] Applied essential addon: kube-proxy
[upgrade/successful] SUCCESS! Your cluster was upgraded to "v1.9.0". Enjoy!
[upgrade/kubelet] Now that your control plane is upgraded, please proceed with upgrading your kubelets in turn.
```
To upgrade the cluster with CoreDNS as the default internal DNS, invoke `kubeadm upgrade apply` with the `--feature-gates=CoreDNS=true` flag.
`kubeadm upgrade apply` does the following:
- Checks that your cluster is in an upgradeable state:
- The API server is reachable,
- All nodes are in the `Ready` state
- The control plane is healthy
- Enforces the version skew policies.
- Makes sure the control plane images are available or available to pull to the machine.
- Upgrades the control plane components or rollbacks if any of them fails to come up.
- Applies the new `kube-dns` and `kube-proxy` manifests and enforces that all necessary RBAC rules are created.
- Creates new certificate and key files of apiserver and backs up old files if they're about to expire in 180 days.
4. Manually upgrade your Software Defined Network (SDN).
Your Container Network Interface (CNI) provider may have its own upgrade instructions to follow.
Check the [addons](/docs/concepts/cluster-administration/addons/) page to
find your CNI provider and see if there are additional upgrade steps
necessary.
## Upgrading your master and node packages
For each host (referred to as `$HOST` below) in your cluster, upgrade `kubelet` by executing the following commands:
1. Prepare the host for maintenance, marking it unschedulable and evicting the workload:
```shell
kubectl drain $HOST --ignore-daemonsets
```
When running this command against the master host, this error is expected and can be safely ignored (since there are static pods running on the master):
```shell
node "master" already cordoned
error: pods not managed by ReplicationController, ReplicaSet, Job, DaemonSet or StatefulSet (use --force to override): etcd-kubeadm, kube-apiserver-kubeadm, kube-controller-manager-kubeadm, kube-scheduler-kubeadm
```
2. Upgrade the Kubernetes package versions on the `$HOST` node by using a Linux distribution-specific package manager:
If the host is running a Debian-based distro such as Ubuntu, run:
```shell
apt-get update
apt-get upgrade
```
If the host is running CentOS or the like, run:
```shell
yum update
```
Now the new version of the `kubelet` should be running on the host. Verify this using the following command on `$HOST`:
```shell
systemctl status kubelet
```
3. Bring the host back online by marking it schedulable:
```shell
kubectl uncordon $HOST
```
4. After upgrading `kubelet` on each host in your cluster, verify that all nodes are available again by executing the following (from anywhere, for example, from outside the cluster):
```shell
kubectl get nodes
```
If the `STATUS` column of the above command shows `Ready` for all of your hosts, you are done.
## Recovering from a failure state
If `kubeadm upgrade` somehow fails and fails to roll back, for example due to an unexpected shutdown during execution,
you can run `kubeadm upgrade` again as it is idempotent and should eventually make sure the actual state is the desired state you are declaring.
You can use `kubeadm upgrade` to change a running cluster with `x.x.x --> x.x.x` with `--force`, which can be used to recover from a bad state.
{{% /capture %}}
content/en/docs/tasks/administer-cluster/kubeadm/kubeadm-upgrade-ha.md
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---
reviewers:
- jamiehannaford
- jamiehannaford
- luxas
- timothysc
- timothysc
- jbeda
title: Upgrading kubeadm HA clusters from 1.9.x to 1.9.y
title: Upgrading kubeadm HA clusters from v1.11 to v1.12
content_template: templates/task
---
{{% capture overview %}}
This guide is for upgrading `kubeadm` HA clusters from version 1.9.x to 1.9.y where `y > x`. The term "`kubeadm` HA clusters" refers to clusters of more than one master node created with `kubeadm`. To set up an HA cluster for Kubernetes version 1.9.x `kubeadm` requires additional manual steps. See [Creating HA clusters with kubeadm](/docs/setup/independent/high-availability/) for instructions on how to do this. The upgrade procedure described here targets clusters created following those very instructions. See [Upgrading/downgrading kubeadm clusters between v1.8 to v1.9](/docs/tasks/administer-cluster/kubeadm-upgrade-1-9/) for more instructions on how to create an HA cluster with `kubeadm`.
This page explains how to upgrade a highly available (HA) Kubernetes cluster created with `kubeadm` from version 1.11.x to version 1.12.x. In addition to upgrading, you must also follow the instructions in [Creating HA clusters with kubeadm](/docs/setup/independent/high-availability/).
{{% /capture %}}
@@ -18,119 +18,223 @@ This guide is for upgrading `kubeadm` HA clusters from version 1.9.x to 1.9.y wh
Before proceeding:
- You need to have a functional `kubeadm` HA cluster running version 1.9.0 or higher in order to use the process described here.
- Make sure you read the [release notes](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.9.md) carefully.
- Note that `kubeadm upgrade` will not touch any of your workloads, only Kubernetes-internal components. As a best-practice you should back up anything important to you. For example, any application-level state, such as a database and application might depend on (like MySQL or MongoDB) should be backed up beforehand.
- Read [Upgrading/downgrading kubeadm clusters between v1.8 to v1.9](/docs/tasks/administer-cluster/kubeadm-upgrade-1-9/) to learn about the relevant prerequisites.
- You need to have a `kubeadm` HA cluster running version 1.11 or higher.
- Make sure you read the [release notes](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.12.md) carefully.
- Make sure to back up any important components, such as app-level state stored in a database. `kubeadm upgrade` does not touch your workloads, only components internal to Kubernetes, but backups are always a best practice.
- Check the prerequisites for [Upgrading/downgrading kubeadm clusters between v1.11 to v1.12](/docs/tasks/administer-cluster/kubeadm-upgrade-1-12/).
{{< note >}}
**Note**: All commands on any control plane or etcd node should be
run as root.
{{< /note >}}
{{% /capture %}}
{{% capture steps %}}
## Preparation
## Prepare for both methods
Some preparation is needed prior to starting the upgrade. First download the version of `kubeadm` that matches the version of Kubernetes that you are upgrading to:
Upgrade `kubeadm` to the version that matches the version of Kubernetes that you are upgrading to:
```shell
# Use the latest stable release or manually specify a
# released Kubernetes version
export VERSION=$(curl -sSL https://dl.k8s.io/release/stable.txt)
export ARCH=amd64 # or: arm, arm64, ppc64le, s390x
curl -sSL https://dl.k8s.io/release/${VERSION}/bin/linux/${ARCH}/kubeadm > /tmp/kubeadm
chmod a+rx /tmp/kubeadm
apt-mark unhold kubeadm && \
apt-get update && apt-get install -y kubeadm && \
apt-mark hold kubeadm
```
Copy this file to `/tmp` on your primary master if necessary. Run this command for checking prerequisites and determining the versions you will receive:
Check prerequisites and determine the upgrade versions:
```shell
/tmp/kubeadm upgrade plan
kubeadm upgrade plan
```
If the prerequisites are met you'll get a summary of the software versions kubeadm will upgrade to, like this:
You should see something like the following:
Upgrade to the latest stable version:
COMPONENT CURRENT AVAILABLE
API Server v1.9.0 v1.9.2
Controller Manager v1.9.0 v1.9.2
Scheduler v1.9.0 v1.9.2
Kube Proxy v1.9.0 v1.9.2
Kube DNS 1.14.5 1.14.7
Etcd 3.2.7 3.1.11
API Server v1.11.3 v1.12.0
Controller Manager v1.11.3 v1.12.0
Scheduler v1.11.3 v1.12.0
Kube Proxy v1.11.3 v1.12.0
CoreDNS 1.1.3 1.2.2
Etcd 3.2.18 3.2.24
{{< caution >}}
**Caution:** Currently the only supported configuration for kubeadm HA clusters requires the use of an externally managed etcd cluster. Upgrading etcd is not supported as a part of the upgrade. If necessary you will have to upgrade the etcd cluster according to [etcd's upgrade instructions](/docs/tasks/administer-cluster/configure-upgrade-etcd/), which is beyond the scope of these instructions.
{{< /caution >}}
## Stacked control plane nodes
## Upgrading your control plane
### Upgrade the first control plane node
The following procedure must be applied on a single master node and repeated for each subsequent master node sequentially.
Before initiating the upgrade with `kubeadm` `configmap/kubeadm-config` needs to be modified for the current master host. Replace any hard reference to a master host name with the current master hosts' name:
Modify `configmap/kubeadm-config` for this control plane node:
```shell
kubectl get configmap -n kube-system kubeadm-config -o yaml >/tmp/kubeadm-config-cm.yaml
sed -i 's/^\([ \t]*nodeName:\).*/\1 <CURRENT-MASTER-NAME>/' /tmp/kubeadm-config-cm.yaml
kubectl apply -f /tmp/kubeadm-config-cm.yaml --force
kubectl get configmap -n kube-system kubeadm-config -o yaml > kubeadm-config-cm.yaml
```
Now the upgrade process can start. Use the target version determined in the preparation step and run the following command (press “y” when prompted):
Open the file in an editor and replace the following values:
- `api.advertiseAddress`
This should be set to the local node's IP address.
- `etcd.local.extraArgs.advertise-client-urls`
This should be updated to the local node's IP address.
- `etcd.local.extraArgs.initial-advertise-peer-urls`
This should be updated to the local node's IP address.
- `etcd.local.extraArgs.listen-client-urls`
This should be updated to the local node's IP address.
- `etcd.local.extraArgs.listen-peer-urls`
This should be updated to the local node's IP address.
- `etcd.local.extraArgs.initial-cluster`
This should be updated to include the hostname and IP address pairs for each control plane node in the cluster. For example:
"ip-172-31-92-42=https://172.31.92.42:2380,ip-172-31-89-186=https://172.31.89.186:2380,ip-172-31-90-42=https://172.31.90.42:2380"
You must also pass an additional argument (`initial-cluster-state: existing`) to etcd.local.extraArgs.
```shell
/tmp/kubeadm upgrade apply v<YOUR-CHOSEN-VERSION-HERE>
kubectl apply -f kubeadm-config-cm.yaml --force
```
If the operation was successful you’ll get a message like this:
[upgrade/successful] SUCCESS! Your cluster was upgraded to "v1.9.2". Enjoy!
To upgrade the cluster with CoreDNS as the default internal DNS, invoke `kubeadm upgrade apply` with the `--feature-gates=CoreDNS=true` flag.
Next, manually upgrade your CNI provider
Your Container Network Interface (CNI) provider may have its own upgrade instructions to follow. Check the [addons](/docs/concepts/cluster-administration/addons/) page to find your CNI provider and see if there are additional upgrade steps necessary.
{{< note >}}
**Note:** The `kubeadm upgrade apply` step has been known to fail when run initially on the secondary masters (timed out waiting for the restarted static pods to come up). It should succeed if retried after a minute or two.
{{< /note >}}
## Upgrade base software packages
At this point all the static pod manifests in your cluster, for example API Server, Controller Manager, Scheduler, Kube Proxy have been upgraded, however the base software, for example `kubelet`, `kubectl`, `kubeadm` installed on your nodes’ OS are still of the old version. For upgrading the base software packages we will upgrade them and restart services on all nodes one by one:
Start the upgrade:
```shell
# use your distro's package manager, e.g. 'yum' on RH-based systems
kubeadm upgrade apply v<YOUR-CHOSEN-VERSION-HERE>
```
You should see something like the following:
[upgrade/successful] SUCCESS! Your cluster was upgraded to "v1.12.0". Enjoy!
The `kubeadm-config` ConfigMap is now updated from `v1alpha2` version to `v1alpha3`.
### Upgrading additional control plane nodes
Each additional control plane node requires modifications that are different from the first control plane node. Run:
```shell
kubectl get configmap -n kube-system kubeadm-config -o yaml > kubeadm-config-cm.yaml
```
Open the file in an editor and replace the following values for `ClusterConfiguration`:
- `etcd.local.extraArgs.advertise-client-urls`
This should be updated to the local node's IP address.
- `etcd.local.extraArgs.initial-advertise-peer-urls`
This should be updated to the local node's IP address.
- `etcd.local.extraArgs.listen-client-urls`
This should be updated to the local node's IP address.
- `etcd.local.extraArgs.listen-peer-urls`
This should be updated to the local node's IP address.
You must also modify the `ClusterStatus` to add a mapping for the current host under apiEndpoints.
Add an annotation for the cri-socket to the current node, for example to use docker:
```shell
kubectl annotate node <nodename> kubeadm.alpha.kubernetes.io/cri-socket=/var/run/dockershim.sock
```
Start the upgrade:
```shell
kubeadm upgrade apply v<YOUR-CHOSEN-VERSION-HERE>
```
You should see something like the following:
[upgrade/successful] SUCCESS! Your cluster was upgraded to "v1.12.0". Enjoy!
## External etcd
### Upgrade each control plane
Get a copy of the kubeadm config used to create this cluster. The config should be the same for every node. The config must exist on every control plane node before the upgrade begins.
```
# on each control plane node
kubectl get configmap -n kube-system kubeadm-config -o jsonpath={.data.MasterConfiguration} > kubeadm-config.yaml
```
Now run the upgrade on each control plane node one at a time.
```
kubeadm upgrade apply v1.12.0 --config kubeadm-config.yaml
```
### Upgrade etcd
Kubernetes v1.11 to v1.12 only changed the patch version of etcd from v3.2.18 to v3.2.24. This is a rolling upgrade with no downtime, because you can run both versions in the same cluster.
On the first host, modify the etcd manifest:
```shell
sed -i 's/3.2.18/3.2.24/' /etc/kubernetes/manifests/etcd.yaml
```
Wait for the etcd process to reconnect. There will be error warnings in the other etcd node logs. This is expected.
Repeat this step on the other etcd hosts.
## Next steps
### Manually upgrade your CNI provider
Your Container Network Interface (CNI) provider might have its own upgrade instructions to follow. Check the [addons](/docs/concepts/cluster-administration/addons/) page to find your CNI provider and see whether you need to take additional upgrade steps.
### Update kubelet and kubectl packages
Upgrade the kubelet and kubectl by running the following on each node:
```shell
# use your distro's package manager, e.g. 'apt-get' on Debian-based systems
# for the versions stick to kubeadm's output (see above)
yum install -y kubelet-<NEW-K8S-VERSION> kubectl-<NEW-K8S-VERSION> kubeadm-<NEW-K8S-VERSION> kubernetes-cni-<NEW-CNI-VERSION>
apt-mark unhold kubelet kubectl && \
apt-get update && \
apt-get install kubelet=<NEW-K8S-VERSION> kubectl=<NEW-K8S-VERSION> && \
apt-mark hold kubelet kubectl && \
systemctl restart kubelet
```
In this example an _rpm_-based system is assumed and `yum` is used for installing the upgraded software. On _deb_-based systems it will be `apt-get update` and then `apt-get install <PACKAGE>=<NEW-K8S-VERSION>` for all packages.
In this example a _deb_-based system is assumed and `apt-get` is used for installing the upgraded software. On rpm-based systems the command is `yum install <PACKAGE>=<NEW-K8S-VERSION>` for all packages.
Now the new version of the `kubelet` should be running on the host. Verify this using the following command on the respective host:
Verify that the new version of the kubelet is running:
```shell
systemctl status kubelet
```
Verify that the upgraded node is available again by executing the following from wherever you run `kubectl` commands:
Verify that the upgraded node is available again by running the following command from wherever you run `kubectl`:
```shell
kubectl get nodes
```
If the `STATUS` column of the above command shows `Ready` for the upgraded host, you can continue (you may have to repeat this for a couple of time before the node gets `Ready`).
If the `STATUS` column shows `Ready` for the upgraded host, you can continue. You might need to repeat the command until the node shows `Ready`.
## If something goes wrong
If the upgrade fails the situation afterwards depends on the phase in which things went wrong:
If the upgrade fails, see whether one of the following scenarios applies:
1. If `/tmp/kubeadm upgrade apply` failed to upgrade the cluster it will try to perform a rollback. Hence if that happened on the first master, chances are pretty good that the cluster is still intact.
- If `kubeadm upgrade apply` failed to upgrade the cluster, it will try to perform a rollback. If this is the case on the first master, the cluster is probably still intact.
You can run `/tmp/kubeadm upgrade apply` again as it is idempotent and should eventually make sure the actual state is the desired state you are declaring. You can use `/tmp/kubeadm upgrade apply` to change a running cluster with `x.x.x --> x.x.x` with `--force`, which can be used to recover from a bad state.
You can run `kubeadm upgrade apply` again, because it is idempotent and should eventually make sure the actual state is the desired state you are declaring. You can run `kubeadm upgrade apply` to change a running cluster with `x.x.x --> x.x.x` with `--force` to recover from a bad state.
2. If `/tmp/kubeadm upgrade apply` on one of the secondary masters failed you still have a working, upgraded cluster, but with the secondary masters in a somewhat undefined condition. You will have to find out what went wrong and join the secondaries manually. As mentioned above, sometimes upgrading one of the secondary masters fails waiting for the restarted static pods first, but succeeds when the operation is simply repeated after a little pause of one or two minutes.
- If `kubeadm upgrade apply` on one of the secondary masters failed, the cluster is upgraded and working, but the secondary masters are in an undefined state. You need to investigate further and join the secondaries manually.
{{% /capture %}}