Fix ArgoCD ApplicationSet Generator Error

The Problem

ArgoCD ApplicationSet fails with generator errors. Applications are not created or are created incorrectly.

Root Cause

ApplicationSet generators fail when:

• Git repository is unreachable
• Directory path does not exist
• Template variables are undefined
• Generator produces empty results

Fix

Check ApplicationSet Controller Logs

kubectl logs -n argocd deployment/argocd-applicationset-controller --tail=100

Common Fixes

Git generator — repository not found:

spec:
  generators:
    - git:
        repoURL: https://github.com/org/repo.git
        revision: HEAD
        directories:
          - path: "apps/*"   # Ensure this path exists

List generator — validate entries:

spec:
  generators:
    - list:
        elements:
          - cluster: production
            url: https://kubernetes.default.svc
          - cluster: staging
            url: https://staging-cluster:6443

Matrix generator — check both sub-generators independently first.

Validate Before Applying

# Dry-run to see what applications would be created
kubectl apply --dry-run=server -f applicationset.yaml

Related Resources

• ArgoCD Cheat Sheet
• Fix ArgoCD App of Apps Sync Issues