Merge master into dev-1.20 to keep in sync

This commit is contained in:
Somtochi Onyekwere
2020-10-07 15:36:49 -07:00
82 changed files with 3337 additions and 779 deletions
@@ -438,7 +438,7 @@ If you want to use project quotas, you should:
[feature gate](/docs/reference/command-line-tools-reference/feature-gates/)
in the kubelet configuration.
* Ensure that the the root filesystem (or optional runtime filesystem)
* Ensure that the root filesystem (or optional runtime filesystem)
has project quotas enabled. All XFS filesystems support project quotas.
For ext4 filesystems, you need to enable the project quota tracking feature
while the filesystem is not mounted.
@@ -181,8 +181,8 @@ are accounted for in Kubernetes.
## {{% heading "whatsnext" %}}
- [RuntimeClass Design](https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/runtime-class.md)
- [RuntimeClass Scheduling Design](https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/runtime-class-scheduling.md)
- [RuntimeClass Design](https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/585-runtime-class/README.md)
- [RuntimeClass Scheduling Design](https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/585-runtime-class/README.md#runtimeclass-scheduling)
- Read about the [Pod Overhead](/docs/concepts/configuration/pod-overhead/) concept
- [PodOverhead Feature Design](https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/20190226-pod-overhead.md)
@@ -44,9 +44,9 @@ Kubernetes as a project currently supports and maintains [GCE](https://git.k8s.i
* [NGINX, Inc.](https://www.nginx.com/) offers support and maintenance for the
[NGINX Ingress Controller for Kubernetes](https://www.nginx.com/products/nginx/kubernetes-ingress-controller).
* [Skipper](https://opensource.zalando.com/skipper/kubernetes/ingress-controller/) HTTP router and reverse proxy for service composition, including use cases like Kubernetes Ingress, designed as a library to build your custom proxy
* [Traefik](https://github.com/containous/traefik) is a fully featured ingress controller
* [Traefik](https://github.com/traefik/traefik) is a fully featured ingress controller
([Let's Encrypt](https://letsencrypt.org), secrets, http2, websocket), and it also comes with commercial
support by [Containous](https://containo.us/services).
support by [Traefik Labs](https://traefik.io).
## Using multiple Ingress controllers
@@ -411,7 +411,7 @@ type: kubernetes.io/tls
Referencing this secret in an Ingress tells the Ingress controller to
secure the channel from the client to the load balancer using TLS. You need to make
sure the TLS secret you created came from a certificate that contains a Common
Name (CN), also known as a Fully Qualified Domain Name (FQDN) for `sslexample.foo.com`.
Name (CN), also known as a Fully Qualified Domain Name (FQDN) for `https-example.foo.com`.
{{< codenew file="service/networking/tls-example-ingress.yaml" >}}
@@ -28,8 +28,8 @@ Init containers are exactly like regular containers, except:
* Init containers always run to completion.
* Each init container must complete successfully before the next one starts.
If a Pod's init container fails, Kubernetes repeatedly restarts the Pod until the init container
succeeds. However, if the Pod has a `restartPolicy` of Never, Kubernetes does not restart the Pod.
If a Pod's init container fails, the kubelet repeatedly restarts that init container until it succeeds.
However, if the Pod has a `restartPolicy` of Never, and an init container fails during startup of that Pod, Kubernetes treats the overall Pod as failed.
To specify an init container for a Pod, add the `initContainers` field into
the Pod specification, as an array of objects of type
@@ -342,7 +342,9 @@ place, the {{< glossary_tooltip text="kubelet" term_id="kubelet" >}} attempts gr
shutdown.
Typically, the container runtime sends a TERM signal to the main process in each
container. Once the grace period has expired, the KILL signal is sent to any remaining
container. Many container runtimes respect the `STOPSIGNAL` value defined in the container
image and send this instead of TERM.
Once the grace period has expired, the KILL signal is sent to any remaining
processes, and the Pod is then deleted from the
{{< glossary_tooltip text="API Server" term_id="kube-apiserver" >}}. If the kubelet or the
container runtime's management service is restarted while waiting for processes to terminate, the
@@ -353,9 +355,9 @@ An example flow:
1. You use the `kubectl` tool to manually delete a specific Pod, with the default grace period
(30 seconds).
1. The Pod in the API server is updated with the time beyond which the Pod is considered "dead"
along with the grace period.
along with the grace period.
If you use `kubectl describe` to check on the Pod you're deleting, that Pod shows up as
"Terminating".
"Terminating".
On the node where the Pod is running: as soon as the kubelet sees that a Pod has been marked
as terminating (a graceful shutdown duration has been set), the kubelet begins the local Pod
shutdown process.
@@ -386,7 +388,7 @@ An example flow:
`SIGKILL` to any processes still running in any container in the Pod.
The kubelet also cleans up a hidden `pause` container if that container runtime uses one.
1. The kubelet triggers forcible removal of Pod object from the API server, by setting grace period
to 0 (immediate deletion).
to 0 (immediate deletion).
1. The API server deletes the Pod's API object, which is then no longer visible from any client.
### Forced Pod termination {#pod-termination-forced}
@@ -190,7 +190,7 @@ close the issue without fixing.
Some docs issues are actually issues with the underlying code, or requests for
assistance when something, for example a tutorial, doesn't work.
For issues unrelated to docs, close the issue with the `triage/support` label and a comment
For issues unrelated to docs, close the issue with the `kind/support` label and a comment
directing the requester to support venues (Slack, Stack Overflow) and, if
relevant, the repository to file an issue for bugs with features (`kubernetes/kubernetes`
is a great place to start).
@@ -31,6 +31,7 @@ be issued, based on a signing request.
The CertificateSigningRequest object includes a PEM-encoded PKCS#10 signing request in
the `spec.request` field. The CertificateSigningRequest denotes the _signer_ (the
recipient that the request is being made to) using the `spec.signerName` field.
Note that `spec.signerName` is a required key after api version `certificates.k8s.io/v1`.
Once created, a CertificateSigningRequest must be approved before it can be signed.
Depending on the signer selected, a CertificateSigningRequest may be automatically approved
@@ -106,8 +107,9 @@ Kubernetes provides built-in signers that each have a well-known `signerName`:
1. Expiration/certificate lifetime - minimum of CSR signer or request.
1. CA bit allowed/disallowed - not allowed.
1. `kubernetes.io/legacy-unknown`: has no guarantees for trust at all. Some distributions may honor these as client
certs, but that behavior is not standard Kubernetes behavior.
1. `kubernetes.io/legacy-unknown`: has no guarantees for trust at all. Some third-party distributions of Kubernetes
may honor client certificates signed by it. The stable CertificateSigningRequest API (version `certificates.k8s.io/v1` and later)
does not allow to set the `signerName` as `kubernetes.io/legacy-unknown`.
Never auto-approved by {{< glossary_tooltip term_id="kube-controller-manager" >}}.
1. Trust distribution: None. There is no standard trust or distribution for this signer in a Kubernetes cluster.
1. Permitted subjects - any
@@ -227,7 +229,7 @@ rules:
## Normal User
There are a few steps are required in order to get normal user to be able to authenticate and invoke API. First, this user must have certificate issued by the Kubernetes Cluster, and then present that Certificate into the API call as the Certificate Header, or through the kubectl.
A few steps are required in order to get normal user to be able to authenticate and invoke an API. First, this user must have certificate issued by the Kubernetes Cluster, and then present that Certificate to the API call as the Certificate Header or through the kubectl.
### Create Private Key
@@ -1096,37 +1096,37 @@ In order from most secure to least secure, the approaches are:
2. Grant a role to the "default" service account in a namespace
If an application does not specify a `serviceAccountName`, it uses the "default" service account.
If an application does not specify a `serviceAccountName`, it uses the "default" service account.
{{< note >}}
Permissions given to the "default" service account are available to any pod
in the namespace that does not specify a `serviceAccountName`.
{{< /note >}}
{{< note >}}
Permissions given to the "default" service account are available to any pod
in the namespace that does not specify a `serviceAccountName`.
{{< /note >}}
For example, grant read-only permission within "my-namespace" to the "default" service account:
For example, grant read-only permission within "my-namespace" to the "default" service account:
```shell
kubectl create rolebinding default-view \
--clusterrole=view \
--serviceaccount=my-namespace:default \
--namespace=my-namespace
```
```shell
kubectl create rolebinding default-view \
--clusterrole=view \
--serviceaccount=my-namespace:default \
--namespace=my-namespace
```
Many [add-ons](/docs/concepts/cluster-administration/addons/) run as the
"default" service account in the `kube-system` namespace.
To allow those add-ons to run with super-user access, grant cluster-admin
permissions to the "default" service account in the `kube-system` namespace.
Many [add-ons](/docs/concepts/cluster-administration/addons/) run as the
"default" service account in the `kube-system` namespace.
To allow those add-ons to run with super-user access, grant cluster-admin
permissions to the "default" service account in the `kube-system` namespace.
{{< caution >}}
Enabling this means the `kube-system` namespace contains Secrets
that grant super-user access to your cluster's API.
{{< /caution >}}
{{< caution >}}
Enabling this means the `kube-system` namespace contains Secrets
that grant super-user access to your cluster's API.
{{< /caution >}}
```shell
kubectl create clusterrolebinding add-on-cluster-admin \
--clusterrole=cluster-admin \
--serviceaccount=kube-system:default
```
```shell
kubectl create clusterrolebinding add-on-cluster-admin \
--clusterrole=cluster-admin \
--serviceaccount=kube-system:default
```
3. Grant a role to all service accounts in a namespace
@@ -1193,7 +1193,7 @@ the [legacy ABAC policy](/docs/reference/access-authn-authz/abac/#policy-file-fo
```
To explain that first command line option in detail: if earlier authorizers, such as Node,
deny a request, then the the RBAC authorizer attempts to authorize the API request. If RBAC
deny a request, then the RBAC authorizer attempts to authorize the API request. If RBAC
also denies that API request, the ABAC authorizer is then run. This means that any request
allowed by *either* the RBAC or ABAC policies is allowed.
@@ -9,7 +9,6 @@ short_description: >
aka:
tags:
- fundamental
- core-object
---
An agent that runs on each {{< glossary_tooltip text="node" term_id="node" >}} in the cluster. It makes sure that {{< glossary_tooltip text="containers" term_id="container" >}} are running in a {{< glossary_tooltip text="Pod" term_id="pod" >}}.
@@ -19,7 +19,7 @@ The `healthz` endpoint is deprecated (since Kubernetes v1.16), and you should us
The `livez` endpoint can be used with the `--livez-grace-period` [flag](/docs/reference/command-line-tools-reference/kube-apiserver) to specify the startup duration.
For a graceful shutdown you can specify the `--shutdown-delay-duration` [flag](/docs/reference/command-line-tools-reference/kube-apiserver) with the `/readyz` endpoint.
Machines that check the `health`/`livez`/`readyz` of the API server should rely on the HTTP status code.
A status code `200` indicates the the API server is `healthy`/`live`/`ready`, depending of the called endpoint.
A status code `200` indicates the API server is `healthy`/`live`/`ready`, depending of the called endpoint.
The more verbose options shown below are intended to be used by human operators to debug their cluster or specially the state of the API server.
The following examples will show how you can interact with the health API endpoints.
@@ -573,7 +573,7 @@ Your main source of help for troubleshooting your Kubernetes cluster should star
Get-NetAdapter | ? Name -Like "vEthernet (Ethernet*"
```
Often it is worthwhile to modify the [InterfaceName](https://github.com/microsoft/SDN/blob/master/Kubernetes/flannel/start.ps1#L6) parameter of the start.ps1 script, in cases where the host's network adapter isn't "Ethernet". Otherwise, consult the output of the `start-kubelet.ps1` script to see if there are errors during virtual network creation.
Often it is worthwhile to modify the [InterfaceName](https://github.com/microsoft/SDN/blob/master/Kubernetes/flannel/start.ps1#L7) parameter of the start.ps1 script, in cases where the host's network adapter isn't "Ethernet". Otherwise, consult the output of the `start-kubelet.ps1` script to see if there are errors during virtual network creation.
1. My Pods are stuck at "Container Creating" or restarting over and over
@@ -1,31 +0,0 @@
#!/bin/bash
#!/usr/bin/env bash
# This script reproduces what the kubelet does
# to calculate memory.available relative to root cgroup.
# current memory usage
memory_capacity_in_kb=$(cat /proc/meminfo | grep MemTotal | awk '{print $2}')
memory_capacity_in_bytes=$((memory_capacity_in_kb * 1024))
memory_usage_in_bytes=$(cat /sys/fs/cgroup/memory/memory.usage_in_bytes)
memory_total_inactive_file=$(cat /sys/fs/cgroup/memory/memory.stat | grep total_inactive_file | awk '{print $2}')
memory_working_set=${memory_usage_in_bytes}
if [ "$memory_working_set" -lt "$memory_total_inactive_file" ];
then
memory_working_set=0
else
memory_working_set=$((memory_usage_in_bytes - memory_total_inactive_file))
fi
memory_available_in_bytes=$((memory_capacity_in_bytes - memory_working_set))
memory_available_in_kb=$((memory_available_in_bytes / 1024))
memory_available_in_mb=$((memory_available_in_kb / 1024))
echo "memory.capacity_in_bytes $memory_capacity_in_bytes"
echo "memory.usage_in_bytes $memory_usage_in_bytes"
echo "memory.total_inactive_file $memory_total_inactive_file"
echo "memory.working_set $memory_working_set"
echo "memory.available_in_bytes $memory_available_in_bytes"
echo "memory.available_in_kb $memory_available_in_kb"
echo "memory.available_in_mb $memory_available_in_mb"
@@ -41,7 +41,7 @@ like `free -m`. This is important because `free -m` does not work in a
container, and if users use the [node
allocatable](/docs/tasks/administer-cluster/reserve-compute-resources/#node-allocatable) feature, out of resource decisions
are made local to the end user Pod part of the cgroup hierarchy as well as the
root node. This [script](/docs/tasks/administer-cluster/memory-available.sh)
root node. This [script](/examples/admin/resource/memory-available.sh)
reproduces the same set of steps that the `kubelet` performs to calculate
`memory.available`. The `kubelet` excludes inactive_file (i.e. # of bytes of
file-backed memory on inactive LRU list) from its calculation as it assumes that
@@ -153,7 +153,7 @@ An older kubectl plugin mechanism provided environment variables such as `KUBECT
kubectl plugins must parse and validate all of the arguments passed to them.
See [using the command line runtime package](#using-the-command-line-runtime-package) for details of a Go library aimed at plugin authors.
Here are some additional cases where users invoke your plugin while providing additional flags and arguments. This builds upon the the `kubectl-foo-bar-baz` plugin from the scenario above.
Here are some additional cases where users invoke your plugin while providing additional flags and arguments. This builds upon the `kubectl-foo-bar-baz` plugin from the scenario above.
If you run `kubectl foo bar baz arg1 --flag=value arg2`, kubectl's plugin mechanism will first try to find the plugin with the longest possible name, which in this case
would be `kubectl-foo-bar-baz-arg1`. Upon not finding that plugin, kubectl then treats the last dash-separated value as an argument (`arg1` in this case), and attempts to find the next longest possible name, `kubectl-foo-bar-baz`.
@@ -405,8 +405,8 @@ behavior:
periodSeconds: 60
```
To allow a final drop of 5 pods, another policy can be added and a selection
strategy of minimum:
To allow a final drop of 5 pods, another policy can be added with a selection
strategy of maximum:
```yaml
behavior:
@@ -39,7 +39,7 @@ helm repo add svc-cat https://svc-catalog-charts.storage.googleapis.com
Check to make sure that it installed successfully by executing the following command:
```shell
helm search service-catalog
helm search repo service-catalog
```
If the installation was successful, the command should output the following:
@@ -65,7 +65,7 @@ Using the latest version of kubectl helps avoid unforeseen issues.
{{< tabs name="kubectl_install" >}}
{{< tab name="Ubuntu, Debian or HypriotOS" codelang="bash" >}}
sudo apt-get update && sudo apt-get install -y apt-transport-https gnupg2
sudo apt-get update && sudo apt-get install -y apt-transport-https gnupg2 curl
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee -a /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update