Update StatefulSet Basics for 1.8 release (#5398)
This commit is contained in:
Kenneth Owens
committed by
Steve Perry
Steve Perry
parent
3810cb23cb
commit
90d95e7ab2
@@ -447,100 +447,12 @@ caused by scaling the StatefulSet down.
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## Updating StatefulSets
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In Kubernetes 1.7, the StatefulSet controller supports automated updates. The
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In Kubernetes 1.7 and later, the StatefulSet controller supports automated updates. The
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strategy used is determined by the `spec.updateStrategy` field of the
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StatefulSet API Object. This feature can be used to upgrade the container
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images, resource requests and/or limits, labels, and annotations of the Pods in a
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StatefulSet. There are two valid update strategies, `OnDelete` and
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`RollingUpdate`.
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### On Delete
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The `OnDelete` update strategy implements the legacy (prior to 1.7) behavior,
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and it is the default update strategy. When you select this update strategy,
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the StatefulSet controller will not automatically update Pods when a
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modification is made to the StatefulSet's `.spec.template` field.
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Patch the container image for the `web` StatefulSet.
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```shell
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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"}]'
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"web" patched
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```
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Delete the `web-0` Pod.
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```shell
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kubectl delete pod web-0
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pod "web-0" deleted
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```
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Watch the `web-0` Pod, and wait for it to transition to Running and Ready.
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```shell
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kubectl get pod web-0 -w
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NAME READY STATUS RESTARTS AGE
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web-0 1/1 Running 0 54s
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web-0 1/1 Terminating 0 1m
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web-0 0/1 Terminating 0 1m
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web-0 0/1 Terminating 0 1m
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web-0 0/1 Terminating 0 1m
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web-0 0/1 Pending 0 0s
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web-0 0/1 Pending 0 0s
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web-0 0/1 ContainerCreating 0 0s
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web-0 1/1 Running 0 3s
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```
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Get the `web` StatefulSet's Pods to view their container images.
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```shell{% raw %}
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kubectl get pod -l app=nginx -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[0].image}{"\n"}{end}'
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web-0 gcr.io/google_containers/nginx-slim:0.7
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web-1 gcr.io/google_containers/nginx-slim:0.8
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web-2 gcr.io/google_containers/nginx-slim:0.8
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{% endraw %}```
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`web-0` has had its image updated, but `web-1` and `web-2` still have the original
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image. Complete the update by deleting the remaining Pods.
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```shell
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kubectl delete pod web-1 web-2
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pod "web-1" deleted
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pod "web-2" deleted
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```
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Watch the StatefulSet's Pods, and wait for all of them to transition to Running and Ready.
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```
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kubectl get pods -w -l app=nginx
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NAME READY STATUS RESTARTS AGE
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web-0 1/1 Running 0 8m
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web-1 1/1 Running 0 4h
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web-2 1/1 Running 0 23m
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NAME READY STATUS RESTARTS AGE
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web-1 1/1 Terminating 0 4h
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web-1 1/1 Terminating 0 4h
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web-1 0/1 Pending 0 0s
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web-1 0/1 Pending 0 0s
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web-1 0/1 ContainerCreating 0 0s
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web-2 1/1 Terminating 0 23m
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web-2 1/1 Terminating 0 23m
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web-1 1/1 Running 0 4s
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web-2 0/1 Pending 0 0s
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web-2 0/1 Pending 0 0s
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web-2 0/1 ContainerCreating 0 0s
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web-2 1/1 Running 0 36s
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```
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Get the Pods to view their container images.
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```shell{% raw %}
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kubectl get pod -l app=nginx -o jsonpath='{range .items[*]}{.metadata.name}{"\t"}{.spec.containers[0].image}{"\n"}{end}'
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web-0 gcr.io/google_containers/nginx-slim:0.7
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web-1 gcr.io/google_containers/nginx-slim:0.7
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web-2 gcr.io/google_containers/nginx-slim:0.7
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{% endraw %}```
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All the Pods in the StatefulSet are now running a new container image.
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StatefulSet. There are two valid update strategies, `RollingUpdate` and
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`OnDelete`.
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### Rolling Update
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@@ -797,6 +709,15 @@ gcr.io/google_containers/nginx-slim:0.7
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By moving the `partition` to `0`, you allowed the StatefulSet controller to
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continue the update process.
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### On Delete
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The `OnDelete` update strategy implements the legacy (1.6 and prior) behavior,
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When you select this update strategy, the StatefulSet controller will not
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automatically update Pods when a modification is made to the StatefulSet's
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`.spec.template` field. This strategy can be selected by setting the
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`.spec.template.updateStrategy.type` to `OnDelete`.
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## Deleting StatefulSets
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StatefulSet supports both Non-Cascading and Cascading deletion. In a
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@@ -13,13 +13,16 @@ spec:
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selector:
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app: nginx
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---
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apiVersion: apps/v1beta1
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apiVersion: apps/v1beta2
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kind: StatefulSet
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metadata:
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name: web
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spec:
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serviceName: "nginx"
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replicas: 2
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selector:
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matchLabels:
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app: nginx
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template:
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metadata:
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labels:
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@@ -13,7 +13,7 @@ spec:
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selector:
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app: nginx
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---
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apiVersion: apps/v1beta1
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apiVersion: apps/v1beta2
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kind: StatefulSet
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metadata:
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name: web
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@@ -21,6 +21,9 @@ spec:
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serviceName: "nginx"
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podManagementPolicy: "Parallel"
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replicas: 2
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selector:
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matchLabels:
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app: nginx
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template:
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metadata:
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labels:
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