Perform a Rollback on a DaemonSet

This page shows how to perform a rollback on a DaemonSetEnsures a copy of a Pod is running across a set of nodes in a cluster. .

Before you begin

You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using Minikube, or you can use one of these Kubernetes playgrounds:

Your Kubernetes server must be at or later than version 1.7. To check the version, enter kubectl version.

You should already know how to perform a rolling update on a DaemonSet.

Performing a rollback on a DaemonSet

Step 1: Find the DaemonSet revision you want to roll back to

You can skip this step if you just want to roll back to the last revision.

List all revisions of a DaemonSet:

kubectl rollout history daemonset <daemonset-name>

This returns a list of DaemonSet revisions:

daemonsets "<daemonset-name>"
REVISION        CHANGE-CAUSE
1               ...
2               ...
...
  • Change cause is copied from DaemonSet annotation kubernetes.io/change-cause to its revisions upon creation. You may specify --record=true in kubectl to record the command executed in the change cause annotation.

To see the details of a specific revision:

kubectl rollout history daemonset <daemonset-name> --revision=1

This returns the details of that revision:

daemonsets "<daemonset-name>" with revision #1
Pod Template:
Labels:       foo=bar
Containers:
app:
 Image:        ...
 Port:         ...
 Environment:  ...
 Mounts:       ...
Volumes:      ...

Step 2: Roll back to a specific revision

# Specify the revision number you get from Step 1 in --to-revision
kubectl rollout undo daemonset <daemonset-name> --to-revision=<revision>

If it succeeds, the command returns:

daemonset "<daemonset-name>" rolled back
Note: If --to-revision flag is not specified, kubectl picks the most recent revision.

Step 3: Watch the progress of the DaemonSet rollback

kubectl rollout undo daemonset tells the server to start rolling back the DaemonSet. The real rollback is done asynchronously inside the cluster control planeThe container orchestration layer that exposes the API and interfaces to define, deploy, and manage the lifecycle of containers. .

To watch the progress of the rollback:

kubectl rollout status ds/<daemonset-name>

When the rollback is complete, the output is similar to:

daemonset "<daemonset-name>" successfully rolled out

Understanding DaemonSet revisions

In the previous kubectl rollout history step, you got a list of DaemonSet revisions. Each revision is stored in a resource named ControllerRevision.

To see what is stored in each revision, find the DaemonSet revision raw resources:

kubectl get controllerrevision -l <daemonset-selector-key>=<daemonset-selector-value>

This returns a list of ControllerRevisions:

NAME                               CONTROLLER                     REVISION   AGE
<daemonset-name>-<revision-hash>   DaemonSet/<daemonset-name>     1          1h
<daemonset-name>-<revision-hash>   DaemonSet/<daemonset-name>     2          1h

Each ControllerRevision stores the annotations and template of a DaemonSet revision.

kubectl rollout undo takes a specific ControllerRevision and replaces DaemonSet template with the template stored in the ControllerRevision. kubectl rollout undo is equivalent to updating DaemonSet template to a previous revision through other commands, such as kubectl edit or kubectl apply.

Note: DaemonSet revisions only roll forward. That is to say, after a rollback completes, the revision number (.revision field) of the ControllerRevision being rolled back to will advance. For example, if you have revision 1 and 2 in the system, and roll back from revision 2 to revision 1, the ControllerRevision with .revision: 1 will become .revision: 3.

Troubleshooting

Last modified May 20, 2020 at 8:53 AM PST: Revise DaemonSet rollback task (82eb6672e)