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Release 1.7 (#4094)

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* Minor fixes in the Deployment doc

Signed-off-by: Michail Kargakis <mkargaki@redhat.com>

* add NodeRestriction to admission-controllers (#3842)

* Admins Can Configure Zones in Storage Class

The PR #38505 (https://github.com/kubernetes/kubernetes/pull/38505) added zones optional parameter to Storage Class for AWS and GCE provisioners.

That's why documentation needs to be updated accordingly.

* document custom resource definitions

* add host paths to psp (#3971)

* add host paths to psp

* add italics

* Update ConfigMap doc to explain TTL-based cache updates (#3989)

* Update ConfigMap doc to explain TTL-based cache updates

* swap word order

Change "When a ConfigMap being already consumed..." to "When a ConfigMap already being consumed..."

* Update NetworkPolicy docs for v1

* StorageOS Volume plugin

* Update GPU docs

* docs: HPA autoscaling/v2alpha1 status conditions

This commit documents the new status conditions feature for HPA
autoscaling/v2alpha1.  It demonstrates how to get the status conditions
using `kubectl describe`, and how to interpret them.

* Update description about NodeRestriction

kubelet node can alse create mirror pods for their own static pods.

* adding storage as a supported resource to node allocatable

Signed-off-by: Vishnu kannan <vishnuk@google.com>

* Add documentation for podpreset opt-out annotation

This adds the annotation for having the podpreset admission controller
to skip (opt-out) manipulating the pod spec.

Also, the annotation format for what presets have acted on a pod has
been modified to add a prefix of "podpreset-". The new naming makes it such
that there is no chance of collision with the newly introduced opt-out
annotation (or future ones yet to be added).

Opt-out annotation PR:
kubernetes/kubernetes#44965

* Update PDB documentation to explain new field (#3885)

* update-docs-pdb

* Addressed erictune@'s comments

* Fix title and add a TOC to the logging concept page

* Patch #4118 for typos

* Describe setting coredns server in nameserver resolv chain

* Address comments in PR #3997.

Comment is in
https://github.com/kubernetes/kubernetes.github.io/pull/3997/files/f6eb59c67e28efc298c87b1ef49a96bc6adacd1e#diff-7a14981f3dd8eb203f897ce6c11d9828

* Update task for DaemonSet history and rollback (#4098)

* Update task for DaemonSet history and rollback

Also remove mentions of templateGeneration field because it's deprecated

* Address comments

* removed lt and gt as operators (#4152)

* removed lt and gt as operators

* replace lt and gt for node-affinfity

* updated based on bsalamat review

* Initial draft of upgrade guide for kubeadm clusters.

In-place upgrades are supported between 1.6 and 1.7 releases. Rollback
instructions to come in a separate commit.

Fixes https://github.com/kubernetes/kubeadm/issues/278

* Add local volume documentation (#4050)

* Add local volume documentation

* Add PV local volume example

* Patch PR #3999

* Add documentation for Stackdriver event exporter

* Add documentation about controller metrics

* Federation: Add task for setting up placement policies (#4075)

* Add task for setting up placement policies

* Update version of management sidecar in policy engine deployment

* Address @nikhiljindal's comments

- Lower case filenames
- Comments in policy
- Typo fixes
- Removed type LoadBalancer from OPA Service

* Add example that sets cluster selector

Per-@nikhiljindal's suggestion

* Fix wording and templating per @chenopis

* PodDisruptionBudget documentation Improvements (#4140)

* Changes from #3885

Title: Update PDB documentation to explain new field
Author: foxish

* Added Placeholder Disruptions Concept Guide

New file: docs/concepts/workloads/pods/disruptions.md
Intented contents: concept for Pod Disruption Budget,
 cross reference to Eviction and Preemption docs.
Linked from: concepts > workloads > pods

* Added placeholder Configuring PDB Task

New file: docs/tasks/run-application/configure-pdb.md
Intented contents: task for writing a Pod Disruption Budget.
Linked from: tasks > configuring-applications > configure pdb.

* Add refs to the "drain a node" task.

* Refactor PDB docs.

Move the "Requesting an eviction" section from:
docs/tasks/administer-cluster/configure-pod-disruption-budget.md
-- which is going away -- to:
docs/tasks/administer-cluster/safely-drain-node.md

The move is verbatim, except for an introductory sentence.

Also added assignees.

* Refactor of PDB docs

Moved the section:
Specifying a PodDisruptionBudget
from:
docs/tasks/administer-cluster/configure-pod-disruption-budget.md
to:
docs/tasks/run-application/configure-pdb.md
because that former file is going away.
Move is verbatim.

* Explain how Eviction tools should handle failures

* Refactor PDB docs

Move text from:
docs/tasks/administer-cluster/configure-pod-disruption-budget.md
to:
docs/concepts/workloads/pods/disruptions.md

Delete the now empty:
docs/tasks/administer-cluster/configure-pod-disruption-budget.md

Added a redirects_from section to the new doc, containing the path
of the now-deleted doc, plus all the redirects from the deleted
doc.

* Expand PDB Concept guide

Building on a little content from the old task,
greatly expanded the Disruptions concept
guide, including an abstract example.

* Update creating a pdb Task.

* Address review comments.

* Fixed for all cody-clark's review comments

* Address review comments from mml

* Address review comments from maisem

* Fix missing backtick

* Api and Kubectl reference docs updates for 1.7 (#4193)

* Fix includes groups

* Generated kubectl docs for 1.7

* Generated references docs for 1.7 api

* Document node authorization mode

* API Aggregator (#4173)

* API Aggregator

* Additional bullet points

* incorporated feedback for apiserver-aggregation.md

* split setup-api-aggregator.md into two docs and address feedback

* fix link

* addressed docs feedback

* incorporate feedback

* integrate feedback

* Add documentation for DNS stub domains (#4063)

* Add documentation for DNS stub domains

* add additional prereq

* fix image path

* review feedback

* minor grammar and style nits

* documentation for using hostAliases to manage hosts file (#4080)

* documentation for using hostAliases to manage hosts file

* add to table of contents

* review comments

* update the right command to see hosts file

* reformat doc based on suggestion and change some wording

* Fix typo for #4080

* Patch PR #4063

* Fix wording in placement policy task introduction

* Add update to statefulset concepts and basic tutorial (#4174)

* Add update to statefulset concpets and basic tutorial

* Address tech comments.

* Update ESIPP docs for new added API fields

* Custom resource docs

* update audit document with advanced audit features added in 1.7

* kubeadm v1.7 documentation updates (#4018)

* v1.7 updates for kubeadm

* Address review comments

* Address Luke's comments

* Encrypting secrets at rest and cluster security guide

* Edits for Custom DNS Documentation (#4207)

* reorganize custom dns doc

* format fixes

* Update version numbers to 1.7

* Patch PR #4140 (#4215)

* Patch PR #4140

* fix link and typos

* Update PR template

* Update TLS bootstrapping with 1.7 features

This includes documenting the new CSR approver built into the
controller manager and the kubelet alpha features for certificate
rotation.

Since the CSR approver changed over the 1.7 release cycle we need
to call out the migration steps for those using the alpha feature.
This document as a whole could probably use some updates, but the
main focus of this PR is just to get these features minimally
documented before the release.

* Federated ClusterSelector

formatting updates from review

* complete PR #4181 (#4223)

* complete PR #4181

* fix security link

* Extensible admission controller (#4092)

* extensible-admission-controllers

* Update extensible-admission-controllers.md

* more on initializers

* fixes

* Expand external admission webhooks documentation

* wrap at 80 chars

* more

* add reference

* Use correct apigroup for network policy

* Docs changes to PR #4092 (#4224)

* Docs changes to PR #4092

* address feedback

* add doc for --as-group in cli

Add doc for this pr:
https://github.com/kubernetes/kubernetes/pull/43696
This commit is contained in:
zhangchaolei
2017-06-30 13:39:40 +08:00
committed by Dawn Chen
parent cbdb17706f
commit aae3bfaf3e
1620 changed files with 297157 additions and 676 deletions
Download Patch File Download Diff File Expand all files Collapse all files
docs/tutorials/stateful-application/basic-stateful-set.md
+425 -43
View File
@@ -1,6 +1,5 @@
---
assignees:
- bprashanth
- enisoc
- erictune
- foxish
@@ -11,10 +10,9 @@ title: StatefulSet Basics
---
{% capture overview %}
This tutorial provides an introduction to manage applications with
This tutorial provides an introduction to managing applications with
[StatefulSets](/docs/concepts/abstractions/controllers/statefulsets/). It
demonstrates how to create, delete, scale, and update the container image of a
StatefulSet.
demonstrates how to create, delete, scale, and update the Pods of StatefulSets.
{% endcapture %}
{% capture prerequisites %}
@@ -40,7 +38,7 @@ StatefulSets are intended to be used with stateful applications and distributed
systems. However, the administration of stateful applications and
distributed systems on Kubernetes is a broad, complex topic. In order to
demonstrate the basic features of a StatefulSet, and to not conflate the former
topic with the latter, you will deploy a simple web application using StatefulSets.
topic with the latter, you will deploy a simple web application using a StatefulSet.
After this tutorial, you will be familiar with the following.
@@ -48,7 +46,7 @@ After this tutorial, you will be familiar with the following.
* How a StatefulSet manages its Pods
* How to delete a StatefulSet
* How to scale a StatefulSet
* How to update the container image of a StatefulSet's Pods
* How to update a StatefulSet's Pods
{% endcapture %}
{% capture lessoncontent %}
@@ -56,9 +54,9 @@ After this tutorial, you will be familiar with the following.
Begin by creating a StatefulSet using the example below. It is similar to the
example presented in the
[StatefulSets](/docs/concepts/abstractions/controllers/statefulsets/) concept. It creates
a [Headless Service](/docs/user-guide/services/#headless-services), `nginx`, to
control the domain of the StatefulSet, `web`.
[StatefulSets](/docs/concepts/abstractions/controllers/statefulsets/) concept.
It creates a [Headless Service](/docs/user-guide/services/#headless-services),
`nginx`, to publish the IP addresses of Pods in the StatefulSet, `web`.
{% include code.html language="yaml" file="web.yaml" ghlink="/docs/tutorials/stateful-application/web.yaml" %}
@@ -116,13 +114,12 @@ web-1 0/1 ContainerCreating 0 0s
web-1 1/1 Running 0 18s
```
Notice that the `web-0` Pod is launched and set to Pending prior to
launching `web-1`. In fact, `web-1` is not launched until `web-0` is
Notice that the `web-1` Pod is not launched until the `web-0` Pod is
[Running and Ready](/docs/user-guide/pod-states).
## Pods in a StatefulSet
Unlike Pods in other controllers, the Pods in a StatefulSet have a unique
ordinal index and a stable network identity.
Pods in a StatefulSet have a unique ordinal index and a stable network identity.
### Examining the Pod's Ordinal Index
@@ -138,12 +135,13 @@ web-1 1/1 Running 0 1m
As mentioned in the [StatefulSets](/docs/concepts/abstractions/controllers/statefulsets/)
concept, the Pods in a StatefulSet have a sticky, unique identity. This identity
is based on a unique ordinal index that is assigned to each Pod by the Stateful
Set controller. The Pods' names take the form
is based on a unique ordinal index that is assigned to each Pod by the
StatefulSet controller. The Pods' names take the form
`<statefulset name>-<ordinal index>`. Since the `web` StatefulSet has two
replicas, it creates two Pods, `web-0` and `web-1`.
### Using Stable Network Identities
Each Pod has a stable hostname based on its ordinal index. Use
[`kubectl exec`](/docs/user-guide/kubectl/v1.6/#exec) to execute the
`hostname` command in each Pod.
@@ -264,9 +262,9 @@ www-web-0 Bound pvc-15c268c7-b507-11e6-932f-42010a800002 1Gi RWO
www-web-1 Bound pvc-15c79307-b507-11e6-932f-42010a800002 1Gi RWO 48s
```
The StatefulSet controller created two PersistentVolumeClaims that are
bound to two [PersistentVolumes](/docs/concepts/storage/volumes/). As the cluster used
in this tutorial is configured to dynamically provision PersistentVolumes, the
PersistentVolumes were created and bound automatically.
bound to two [PersistentVolumes](/docs/concepts/storage/volumes/). As the
cluster used in this tutorial is configured to dynamically provision
PersistentVolumes, the PersistentVolumes were created and bound automatically.
The NGINX webservers, by default, will serve an index file at
`/usr/share/nginx/html/index.html`. The `volumeMounts` field in the
@@ -331,10 +329,10 @@ web-1
```
Even though `web-0` and `web-1` were rescheduled, they continue to serve their
hostnames because the PersistentVolumes associated with their Persistent
Volume Claims are remounted to their `volumeMount`s. No matter what node `web-0`
and `web-1` are scheduled on, their PersistentVolumes will be mounted to the
appropriate mount points.
hostnames because the PersistentVolumes associated with their
PersistentVolumeClaims are remounted to their `volumeMount`s. No matter what
node `web-0`and `web-1` are scheduled on, their PersistentVolumes will be
mounted to the appropriate mount points.
## Scaling a StatefulSet
Scaling a StatefulSet refers to increasing or decreasing the number of replicas.
@@ -355,7 +353,7 @@ In another terminal window, use `kubectl scale` to scale the number of replicas
to 5.
```shell
kubectl scale statefulset web --replicas=5
kubectl scale sts web --replicas=5
statefulset "web" scaled
```
@@ -397,10 +395,10 @@ kubectl get pods -w -l app=nginx
```
In another terminal, use `kubectl patch` to scale the StatefulSet back down to
3 replicas.
three replicas.
```shell
kubectl patch statefulset web -p '{"spec":{"replicas":3}}'
kubectl patch sts web -p '{"spec":{"replicas":3}}'
"web" patched
```
@@ -424,8 +422,8 @@ web-3 1/1 Terminating 0 42s
### Ordered Pod Termination
The controller deleted one Pod at a time, with respect to its ordinal index,
in reverse order, and it waited for each to be completely shutdown before
The controller deleted one Pod at a time, in reverse order with respect to its
ordinal index, and it waited for each to be completely shutdown before
deleting the next.
Get the StatefulSet's PersistentVolumeClaims.
@@ -445,18 +443,22 @@ There are still five PersistentVolumeClaims and five PersistentVolumes.
When exploring a Pod's [stable storage](#stable-storage), we saw that the
PersistentVolumes mounted to the Pods of a StatefulSet are not deleted when
the StatefulSet's Pods are deleted. This is still true when Pod deletion is
caused by scaling the StatefulSet down. This feature can be used to facilitate
upgrading the container images of Pods in a StatefulSet.
caused by scaling the StatefulSet down.
## Updating Containers
As demonstrated in the [Scaling a StatefulSet](#scaling-a-statefulset) section,
the `replicas` field of a StatefulSet is mutable. The only other field of a
StatefulSet that can be updated is the `spec.template.containers` field.
## Updating StatefulSets
StatefulSet currently *does not* support automated image upgrade. However, you
can update the `image` field of any container in the podTemplate and delete
StatefulSet's Pods one by one, the StatefulSet controller will recreate
each Pod with the new image.
In Kubernetes 1.7, the StatefulSet controller supports automated updates. The
strategy used is determined by the `spec.updateStrategy` field of the
StatefulSet API Object. This feature can be used to upgrade the container
images, resource requests and/or limits, labels, and annotations of the Pods in a
StatefulSet. There are two valid update strategies, `OnDelete` and
`RollingUpdate`.
### On Delete
The `OnDelete` update strategy implements the legacy (prior to 1.7) behavior,
and it is the default update strategy. When you select this update strategy,
the StatefulSet controller will not automatically update Pods when a
modification is made to the StatefulSet's `.spec.template` field.
Patch the container image for the `web` StatefulSet.
@@ -472,7 +474,7 @@ kubectl delete pod web-0
pod "web-0" deleted
```
Watch `web-0`, and wait for the Pod to transition to Running and Ready.
Watch the `web-0` Pod, and wait for it to transition to Running and Ready.
```shell
kubectl get pod web-0 -w
@@ -488,7 +490,7 @@ web-0 0/1 ContainerCreating 0 0s
web-0 1/1 Running 0 3s
```
Get the Pods to view their container images.
Get the `web` StatefulSet's Pods to view their container images.
```shell{% raw %}
kubectl get pod -l app=nginx -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[0].image}{"\n"}{end}'
@@ -497,8 +499,8 @@ web-1 gcr.io/google_containers/nginx-slim:0.8
web-2 gcr.io/google_containers/nginx-slim:0.8
{% endraw %}```
`web-0` has had its image updated. Complete the update by deleting the remaining
Pods.
`web-0` has had its image updated, but `web-0` and `web-1` still have the original
image. Complete the update by deleting the remaining Pods.
```shell
kubectl delete pod web-1 web-2
@@ -506,7 +508,7 @@ pod "web-1" deleted
pod "web-2" deleted
```
Watch the Pods, and wait for all of them to transition to Running and Ready.
Watch the StatefulSet's Pods, and wait for all of them to transition to Running and Ready.
```
kubectl get pods -w -l app=nginx
@@ -540,6 +542,261 @@ web-2 gcr.io/google_containers/nginx-slim:0.7
All the Pods in the StatefulSet are now running a new container image.
### Rolling Update
The `RollingUpdate` update strategy will update all Pods in a StatefulSet, in
reverse ordinal order, while respecting the StatefulSet guarantees.
Patch the `web` StatefulSet to apply the `RollingUpdate` update strategy.
```shell
kubectl patch statefulset web -p '{"spec":{"updateStrategy":{"type":"RollingUpdate"}}}
statefulset "web" patched
```
In one terminal window, patch the `web` StatefulSet to change the container
image again.
```shell
kubectl patch statefulset web --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value":"gcr.io/google_containers/nginx-slim:0.8"}]'
statefulset "web" patched
```
In another terminal, watch the Pods in the StatefulSet.
```shell
kubectl get po -l app=nginx -w
NAME READY STATUS RESTARTS AGE
web-0 1/1 Running 0 7m
web-1 1/1 Running 0 7m
web-2 1/1 Running 0 8m
web-2 1/1 Terminating 0 8m
web-2 1/1 Terminating 0 8m
web-2 0/1 Terminating 0 8m
web-2 0/1 Terminating 0 8m
web-2 0/1 Terminating 0 8m
web-2 0/1 Terminating 0 8m
web-2 0/1 Pending 0 0s
web-2 0/1 Pending 0 0s
web-2 0/1 ContainerCreating 0 0s
web-2 1/1 Running 0 19s
web-1 1/1 Terminating 0 8m
web-1 0/1 Terminating 0 8m
web-1 0/1 Terminating 0 8m
web-1 0/1 Terminating 0 8m
web-1 0/1 Pending 0 0s
web-1 0/1 Pending 0 0s
web-1 0/1 ContainerCreating 0 0s
web-1 1/1 Running 0 6s
web-0 1/1 Terminating 0 7m
web-0 1/1 Terminating 0 7m
web-0 0/1 Terminating 0 7m
web-0 0/1 Terminating 0 7m
web-0 0/1 Terminating 0 7m
web-0 0/1 Terminating 0 7m
web-0 0/1 Pending 0 0s
web-0 0/1 Pending 0 0s
web-0 0/1 ContainerCreating 0 0s
web-0 1/1 Running 0 10s
```
The Pods in the StatefulSet are updated in reverse ordinal order. The
StatefulSet controller terminates each Pod, and waits for it to transition to Running and
Ready prior to updating the next Pod. Note that, even though the StatefulSet
controller will not proceed to update the next Pod until its ordinal successor
is Running and Ready, it will restore any Pod that fails during the update to
its current version. Pods that have already received the update will be
restored to the updated version, and Pods that have not yet received the
update will be restored to the previous version. In this way, the controller
attempts to continue to keep the application healthy and the update consistent
in the presence of intermittent failures.
Get the Pods to view their container images.
```shell{% raw %}
for p in 0 1 2; do kubectl get po web-$p --template '{{range $i, $c := .spec.containers}}{{$c.image}}{{end}}'; echo; done
gcr.io/google_containers/nginx-slim:0.8
gcr.io/google_containers/nginx-slim:0.8
gcr.io/google_containers/nginx-slim:0.8
{% endraw %}
```
All the Pods in the StatefulSet are now running the previous container image.
**Tip** You can also use `kubectl rollout status sts/<name>` to view
the status of a rolling update.
#### Staging an Update
You can stage an update to a StatefulSet by using the `partition` parameter of
the `RollingUpdate` update strategy. A staged update will keep all of the Pods
in the StatefulSet at the current version while allowing mutations to the
StatefulSet's `.spec.template`.
Patch the `web` StatefulSet to add a partition to the `updateStrategy` field.
```shell
kubectl patch statefulset web -p '{"spec":{"updateStrategy":{"type":"RollingUpdate","rollingUpdate":{"partition":3}}}}'
statefulset "web" patched
```
Patch the StatefulSet again to change the container's image.
```shell
kubectl patch statefulset web --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value":"gcr.io/google_containers/nginx-slim:0.7"}]'
statefulset "web" patched
```
Delete a Pod in the StatefulSet.
```shell
kubectl delete po web-2
pod "web-2" deleted
```
Wait for the Pod to be Running and Ready.
```shell
kubectl get po -lapp=nginx -w
NAME READY STATUS RESTARTS AGE
web-0 1/1 Running 0 4m
web-1 1/1 Running 0 4m
web-2 0/1 ContainerCreating 0 11s
web-2 1/1 Running 0 18s
```
Get the Pod's container.
```shell{% raw %}
get po web-2 --template '{{range $i, $c := .spec.containers}}{{$c.image}}{{end}}'
gcr.io/google_containers/nginx-slim:0.8
{% endraw %}
```
Notice that, even though the update strategy is `RollingUpdate` the StatefulSet
controller restored the Pod with its original container. This is because the
ordinal of the Pod is less than the `partition` specified by the
`updateStrategy`.
#### Rolling Out a Canary
You can roll out a canary to test a modification by decrementing the `partition`
you specified [above](#staging-an-update).
Patch the StatefulSet to decrement the partition.
```shell
kubectl patch statefulset web -p '{"spec":{"updateStrategy":{"type":"RollingUpdate","rollingUpdate":{"partition":2}}}}'
statefulset "web" patched
```
Wait for `web-2` to be Running and Ready.
```shell
kubectl get po -lapp=nginx -w
NAME READY STATUS RESTARTS AGE
web-0 1/1 Running 0 4m
web-1 1/1 Running 0 4m
web-2 0/1 ContainerCreating 0 11s
web-2 1/1 Running 0 18s
```
Get the Pod's container.
```shell{% raw %}
kubectl get po web-2 --template '{{range $i, $c := .spec.containers}}{{$c.image}}{{end}}'
gcr.io/google_containers/nginx-slim:0.7
{% endraw %}
```
When you changed the `partition`, the StatefulSet controller automatically
updated the `web-2` Pod because the Pod's ordinal was less than or equal to
the `partition`.
Delete the `web-1` Pod.
```shell
kubectl delete po web-1
pod "web-1" deleted
```
Wait for the `web-1` Pod to be Running and Ready.
```shell
kubectl get po -lapp=nginx -w
NAME READY STATUS RESTARTS AGE
web-0 1/1 Running 0 6m
web-1 0/1 Terminating 0 6m
web-2 1/1 Running 0 2m
web-1 0/1 Terminating 0 6m
web-1 0/1 Terminating 0 6m
web-1 0/1 Terminating 0 6m
web-1 0/1 Pending 0 0s
web-1 0/1 Pending 0 0s
web-1 0/1 ContainerCreating 0 0s
web-1 1/1 Running 0 18s
```
Get the `web-1` Pods container.
```shell{% raw %}
get po web-1 --template '{{range $i, $c := .spec.containers}}{{$c.image}}{{end}}'
gcr.io/google_containers/nginx-slim:0.8
{% endraw %}
```
`web-1` was restored to its original configuration because the Pod's ordinal
was less than the partition. When a partition is specified, all Pods with an
ordinal that is greater than or equal to the partition will be updated when the
StatefulSet's `.spec.template` is updated. If a Pod that has an ordinal less
than the partition is deleted or otherwise terminated, it will be restored to
its original configuration.
#### Phased Roll Outs
You can perform a phased roll out (e.g. a linear, geometric, or exponential
roll out) using a partitioned rolling update in a similar manner to how you
rolled out a [canary](#rolling-out-a-canary). To perform a phased roll out, set
the `partition` to the ordinal at which you want the controller to pause the
update.
The partition is currently set to `2`. Set the partition to `0`.
```shell
kubectl patch statefulset web -p '{"spec":{"updateStrategy":{"type":"RollingUpdate","rollingUpdate":{"partition":0}}}}'
statefulset "web" patched
```
Wait for all of the Pods in the StatefulSet to become Running and Ready.
```shell
kubectl get po -lapp=nginx -w
NAME READY STATUS RESTARTS AGE
web-0 1/1 Running 0 3m
web-1 0/1 ContainerCreating 0 11s
web-2 1/1 Running 0 2m
web-1 1/1 Running 0 18s
web-0 1/1 Terminating 0 3m
web-0 1/1 Terminating 0 3m
web-0 0/1 Terminating 0 3m
web-0 0/1 Terminating 0 3m
web-0 0/1 Terminating 0 3m
web-0 0/1 Terminating 0 3m
web-0 0/1 Pending 0 0s
web-0 0/1 Pending 0 0s
web-0 0/1 ContainerCreating 0 0s
web-0 1/1 Running 0 3s
```
Get the Pod's containers.
```shell{% raw %}
for p in 0 1 2; do kubectl get po web-$p --template '{{range $i, $c := .spec.containers}}{{$c.image}}{{end}}'; echo; done
gcr.io/google_containers/nginx-slim:0.7
gcr.io/google_containers/nginx-slim:0.7
gcr.io/google_containers/nginx-slim:0.7
{% endraw %}
```
By moving the `partition` to `0`, you allowed the StatefulSet controller to
continue the update process.
## Deleting StatefulSets
StatefulSet supports both Non-Cascading and Cascading deletion. In a
@@ -596,7 +853,7 @@ As the `web` StatefulSet has been deleted, `web-0` has not been relaunched.
In one terminal, watch the StatefulSet's Pods.
```
```shell
kubectl get pods -w -l app=nginx
```
@@ -733,6 +990,131 @@ kubectl delete statefulset web
statefulset "web" deleted
```
## Pod Management Policy
For some distributed systems, the StatefulSet ordering guarantees are
unnecessary and/or undesirable. These systems require only uniqueness and
identity. To address this, in Kubernetes 1.7, we introduced
`.spec.podManagementPolicy` to the StatefulSet API Object.
### OrderedReady Pod Management
`OrderedReady` pod management is the default for StatefulSets. It tells the
StatefulSet controller to respect the ordering guarantees demonstrated
above.
### Parallel Pod Management
`Parallel` pod management tells the StatefulSet controller to launch or
terminate all Pods in parallel, and to not wait for Pods to becoming Running
and Ready or completely terminated prior to launching or terminating another
Pod.
{% include code.html language="yaml" file="webp.yaml" ghlink="/docs/tutorials/stateful-application/webp.yaml" %}
Download the example above, and save it to a file named `webp.yaml`
This manifest is identical to the one you
[downloaded above](creating-a-statefulset) except that the `.spec.podManagementPolicy`
of the `web` StatefulSet is set to `Parallel`.
In one terminal, watch the Pods in the StatefulSet.
```shell
kubectl get po -lapp=nginx -w
```
In another terminal, create the StatefulSet and Service in the manifest.
```shell
kubectl create -f webp.yaml
service "nginx" created
statefulset "web" created
```
Examine the output of the `kubectl get` command that you executed in the first terminal.
```shell
kubectl get po -lapp=nginx -w
NAME READY STATUS RESTARTS AGE
web-0 0/1 Pending 0 0s
web-0 0/1 Pending 0 0s
web-1 0/1 Pending 0 0s
web-1 0/1 Pending 0 0s
web-0 0/1 ContainerCreating 0 0s
web-1 0/1 ContainerCreating 0 0s
web-0 1/1 Running 0 10s
web-1 1/1 Running 0 10s
```
The StatefulSet controller launched both `web-0` and `web-1` at the same time.
Keep the second terminal open, and, in another terminal window scale the
StatefulSet.
```shell
kubectl scale statefulset/web --replicas=4
statefulset "web" scaled
```
Examine the output of the terminal where the `kubectl get` command is running.
```shell
web-3 0/1 Pending 0 0s
web-3 0/1 Pending 0 0s
web-3 0/1 Pending 0 7s
web-3 0/1 ContainerCreating 0 7s
web-2 1/1 Running 0 10s
web-3 1/1 Running 0 26s
```
The StatefulSet controller launched two new Pods, and it did not wait for
the first to become Running and Ready prior to launching the second.
Keep this terminal open, and in another terminal delete the `web` StatefulSet.
```shell
kubectl delete sts web
```
Again, examine the output of the `kubectl get` command running in the other terminal.
```shell
web-3 1/1 Terminating 0 9m
web-2 1/1 Terminating 0 9m
web-3 1/1 Terminating 0 9m
web-2 1/1 Terminating 0 9m
web-1 1/1 Terminating 0 44m
web-0 1/1 Terminating 0 44m
web-0 0/1 Terminating 0 44m
web-3 0/1 Terminating 0 9m
web-2 0/1 Terminating 0 9m
web-1 0/1 Terminating 0 44m
web-0 0/1 Terminating 0 44m
web-2 0/1 Terminating 0 9m
web-2 0/1 Terminating 0 9m
web-2 0/1 Terminating 0 9m
web-1 0/1 Terminating 0 44m
web-1 0/1 Terminating 0 44m
web-1 0/1 Terminating 0 44m
web-0 0/1 Terminating 0 44m
web-0 0/1 Terminating 0 44m
web-0 0/1 Terminating 0 44m
web-3 0/1 Terminating 0 9m
web-3 0/1 Terminating 0 9m
web-3 0/1 Terminating 0 9m
```
The StatefulSet controller deletes all Pods concurrently, it does not wait for
a Pod's ordinal successor to terminate prior to deleting that Pod.
Close the terminal where the `kubectl get` command is running and delete the `nginx`
Service.
```shell
kubectl delete svc nginx
```
{% endcapture %}
{% capture cleanup %}