Argo CD Application Hooks and Pitfalls to Avoid

Application Hooks Overview and Examples

Hooks can be defined to run before or after the application's deployment. For instance, a script can be run to send a notification to a Slack channel or an email to your team.

To define a hook, a Job must be created.

ℹ️ A Job is a Kubernetes-native resource that creates one or more Pods to perform a specific task that runs to completion and then terminates.

Here is a Job that sends an email after the application has been successfully deployed. It uses the argocd.argoproj.io/hook: PostSync annotation to specify that it should run after the application's synchronization. The argocd.argoproj.io/hook-delete-policy: HookSucceeded annotation is used to delete the Job after it has successfully completed.

# Define a secret to store the SMTP password
---
apiVersion: v1
kind: Secret
metadata:
  name: smtp-password
  namespace: argocd
type: Opaque
stringData:
  password: 
# Define the Job to send an email
---
apiVersion: batch/v1
kind: Job
metadata:
  generateName: email-
  namespace: argocd
  annotations:
    argocd.argoproj.io/hook: PostSync
    argocd.argoproj.io/hook-delete-policy: HookSucceeded
spec:
  template:
    spec:
      containers:
      - name: email
        image: bytemark/smtp
        command: ["/bin/sh"]
        args:
        - "-c"
        - "echo 'Hello World!' | mail -s 'Hello World!' "
        env:
        - name: RELAY_HOST
          value: 
        - name: RELAY_PORT
          value: 
        - name: RELAY_USERNAME
          value: 
        - name: RELAY_PASSWORD
          valueFrom:
            secretKeyRef:
              name: smtp-password
              key: password
      # Never restart the job container if it fails
      # but let the job controller handle retries
      restartPolicy: Never
  # Retry the job 4 times if it fails then give up
  backoffLimit: 4

You should be able to see the Job after running the previous command:

kubectl get jobs -n argocd

As well as the logs of the created container:

kubectl logs -n argocd email--

As in the above example, we can create a Job that will send a notification to a Slack channel:

apiVersion: batch/v1
kind: Job
metadata

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