ArgoCD App of Apps can manage mixed YAML/Helm workloads but may introduce unnecessary complexity; evaluate against simpler tools like Keel based on team needs and scale.

Diagnosis: When App of Apps Makes Sense

App of Apps is designed for hierarchical, multi-application deployments. For a single folder with mixed YAML and Helm charts, it’s often overkill. The added abstraction introduces sync latency, RBAC complexity, and operational overhead. Use it only if you need:

• Structured dependency management across multiple apps
• Declarative Git-driven lifecycle control for nested resources
• Fine-grained sync policies (e.g., per-app health checks)

If your use case is a flat directory of resources (e.g., a few Helm charts + raw YAML), simpler tools like Keel or plain ArgoCD (without App of Apps) are better.

Workflow: Implementing App of Apps vs. Keel

For ArgoCD App of Apps

1. Create root App manifest: Define the folder as a parent app with project, sourceRepo, and dest fields.
2. Generate child apps: Use Kustomize to patch Helm charts and YAML files into App of Apps manifests.
3. Sync: argocd app sync --repo <repo> --path <path>
4. Validate: Check sync status and health via UI or argocd app get <name>.

For Keel

1. Define HelmRelease or Kustomization CRs: Create YAML files in your repo specifying resources to manage.
2. Deploy Keel: Apply the operator and configure Git repository webhook.
3. Sync: Keel auto-detects changes and applies updates.

Policy Example: App of Apps vs. Keel

App of Apps (Kustomize Patch)

apiVersion: kustomize.config.k8s.io/v1beta1  
kind: Kustomization  
resources:  
  - helmrelease.yaml  
  - crd.yaml  
generatorOptions:  
  disableNameSuffixHash: true  

Keel (HelmRelease CR)

apiVersion: keel.sh/v1  
kind: HelmRelease  
metadata:  
  name: my-app  
spec:  
  chart: ./charts/my-chart  
  version: 1.2.3  
  values:  
    env: dev  

Tooling Comparison

Tradeoffs and Caveats

• App of Apps: Adds 2-3x operational overhead (e.g., managing App manifests, sync loops). Useful for large teams with strict governance but risky for small projects.
• Keel: Lacks granular sync policies and health checks. Ideal for teams prioritizing simplicity over fine-grained control.

Troubleshooting Common Issues

App of Apps

• Sync failures: Check argocd app sync --retry and verify Helm version compatibility.
• RBAC denied: Ensure argocd service account has get, list permissions on target namespaces.
• Child app drift: Use argocd app diff to detect unapplied changes.

Keel

• Webhook timeouts: Increase readTimeout in Keel operator args.
• Image pull errors: Verify imagePullSecrets in HelmRelease CRs.
• No sync after push: Check GitHub/GitLab webhook delivery logs.

Final Verdict

Use App of Apps only if you need its hierarchical control. For most single-folder mixed workloads, Keel or plain ArgoCD is simpler, faster, and less error-prone. Start small, and escalate complexity only when required by scale or compliance.

Source thread: ArgoCD App of Apps for a single folder with mixed YAML/Helm — overkill? Considering Keel instead