Perform a Rollback on a DaemonSet
This page shows how to perform a rollback on a DaemonSet.
Before you begin
You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. 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, enterkubectl 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 only 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
inkubectl
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 plane.
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
.