Argo Workflows: Using the exit handler
2 min read | by Jordi Prats
An exit handler is a template that always executes at the end of a workflow (regardless of whether it completed successfully or returned an error). You can use this run any action, for example: to send notifications after a workflow runs, post the status of the workflow to a webhook, clean up artifacts or run another workflow.
In the following Workflow we are going to make it fail on purpose, and then we are going to use the exit handler to print the status of the workflow:
apiVersion: argoproj.io/v1alpha1 kind: Workflow metadata: generateName: exit-handler- spec: entrypoint: step1 onExit: exit-handler templates: - name: step1 container: image: alpine:latest command: [sh, -c] args: ["echo failed step; exit 1"] - name: exit-handler container: image: alpine:latest command: [sh, -c] # {{workflow.status}} can be: Succeeded, Failed or Error args: ["echo Exit status: {{workflow.status}}"] If we run this workflow, we can see how it is going to fail:
$ kubectl create -f exithandler.yaml ; kubectl get workflow -w workflow.argoproj.io/exit-handler-zx78p created NAME STATUS AGE MESSAGE exit-handler-zx78p Running 0s exit-handler-zx78p Running 10s exit-handler-zx78p Failed 20s Error (exit code 1) The exit handler is being executed at the end of the workflow in a different container:
$ kubectl get pods NAME READY STATUS RESTARTS AGE exit-handler-zx78p 0/2 Error 0 42s exit-handler-zx78p-exit-handler-3923311637 0/2 Completed 0 32s We can get the logs of the step and the exit handler as usual:
$ kubectl logs exit-handler-zx78p time="2024-10-28T04:22:48.156Z" level=info msg="capturing logs" argo=true failed step time="2024-10-28T04:22:49.157Z" level=info msg="sub-process exited" argo=true error="<nil>" Error: exit status 1 $ kubectl logs exit-handler-zx78p-exit-handler-3923311637 time="2024-10-28T04:22:58.064Z" level=info msg="capturing logs" argo=true time="2024-10-28T04:22:59.065Z" level=info msg="sub-process exited" argo=true error="<nil>" The exit handler is executed in a different container, so it doesn't have access to the workflow logs. However, it can access the workflow status using the {{workflow.status}} template variable.
Posted on 01/11/2024