CODEWITHSUNDEEP
kubernetes
Laizer
Laizer

Reputation: 6140

Kubernetes - trigger job when pod restarts

I'd like to run a particular Kubernetes job whenever the pod of particular deployment restarts.

In particular, I have a Redis deployment. It is not backed by permanent storage. When the pod in the Redis deployment restarts, I'd like to populate some keys in Redis.

Is there a way to trigger a job on pod restart?

Upvotes: 1

Views: 2209

Answers (2)

Itamar Lev
Itamar Lev

Reputation: 84

There's a way to rerun the job with the following command:

kubectl get job <job name> -n <namespace> -o json | jq 'del(.spec.selector)' | jq 'del(.spec.template.metadata.labels)'| kubectl replace --force -f -

This works however it's not totally automatic.

The solution which was more effective was to copy the commands in the job ,which were relevant for a single pod, and put in the deployment of the pod. Then whenever it restarts these commands are run.

      containers: 
      - name: <container name>
        command:
          - /bin/sh
          - -c
          - |
            <first command>;
            <second command>;

Upvotes: 0

Amrit
Amrit

Reputation: 2072

The best option comes to my mind is an k8s operator - A simple python/go script watches your target pod (by label, name, namespace, etc.) and performs some actions when the state changes.

An operator is just a deployment with special features. There are various ways to implement, one of them is https://sdk.operatorframework.io/docs/building-operators/golang/quickstart/

You can also use https://github.com/kubernetes-client/python#examples (check the second example).

You can get rid of the job and write your redis logic inside the operator itself.

Upvotes: 1

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