Automated Container Image Updates with ArgoCD

Automated Image Updates

This guide enables ArgoCD Image Updater to track container images and commit updates back to Git.

Step 1: Store registry credentials in Vault

Create these Vault secrets:

kubectl -n vault exec -it vault-0 -- vault kv put kv/argocd-image-updater/ghcr \
  username="REPLACE_ME" token="REPLACE_ME"

kubectl -n vault exec -it vault-0 -- vault kv put kv/argocd-image-updater/dockerhub \
  username="REPLACE_ME" token="REPLACE_ME"

Step 2: Store Git write-back credentials in Vault

Create a GitHub token with repo write access and store it:

kubectl -n vault exec -it vault-0 -- vault kv put kv/argocd/repo-creds \
  username="REPLACE_ME" token="REPLACE_ME"

Step 3: Let ArgoCD sync

ArgoCD will install ArgoCD Image Updater, create the registry secret, and create the repo credentials.

Step 4: Verify image updates

Look for .argocd-source-<appName>.yaml files added under apps/ after Image Updater runs.

Notes

• Image rules live in infrastructure/argocd-image-updater/image-updater.yaml.
• Registry secrets are created by External Secrets in infrastructure/external-secrets/.
• Updates commit to the tracked branch (master) so ArgoCD can auto-sync.
• Apps should include a kustomization.yaml so ArgoCD can apply Image Updater overrides.