Argocdclusterbootstrapping

ArgoCD Cluster Bootstrapping

Operational skill for bootstrapping ArgoCD clusters using the app-of-apps pattern with Kustomize-curated ApplicationSets. Covers diagnosing sync failures from missing CRDs, creating root Applications for GitOps lifecycle management, and onboarding new clusters to existing ApplicationSet generators.

Workflow Routing

Examples

Example 1: Diagnose a sync failure caused by missing CRD

User: "example-app-hub-adp-agent is SyncFailed with missing AzureKeyVaultSecret CRD"
-> Invokes DiagnoseSyncFailure workflow
-> Traces dependency chain: adp-agent needs akv2k8s CRDs
-> Checks if akv2k8s ApplicationSet exists on cluster
-> Identifies root cause: ApplicationSet never deployed
-> Recommends fix via root Application or manual apply

Example 2: Create a root Application for GitOps ApplicationSet management

User: "Create a root Application to manage all ApplicationSets via GitOps"
-> Invokes CreateRootApplication workflow
-> Audits applicationset directory for active vs inactive files
-> Creates kustomization.yaml with curated list
-> Creates root-applicationsets.yaml Application
-> Provides bootstrap instructions for ArgoCD UI

Example 3: Add a new cluster to existing ApplicationSets

User: "Onboard example-app-prd cluster to the otel ApplicationSet"
-> Invokes OnboardCluster workflow
-> Reads existing ApplicationSet generator list
-> Adds new cluster element with correct URL, project, branch
-> Creates values file in argo-cd-helm-values repo
-> Validates with kustomize build

Key Patterns

• App-of-Apps via Kustomize: Root Application watches infra-team/applicationset/ with kustomization.yaml for explicit curation
• Multi-source Helm: ApplicationSets combine chart repo + Git values repo using $values ref
• Sync waves: Dependencies deploy first (e.g., akv2k8s at wave -5, consumers at wave +5)
• ServerSideApply: Prevents adoption conflicts when bringing existing resources under GitOps
• Bootstrap chicken-and-egg: Root Application must be applied once via ArgoCD UI, then self-manages
• Pure GitOps: No kubectl apply/patch/edit/delete — all changes via Git commits

Architecture Reference

root-applicationsets (Application)
  └── watches: infra-team/applicationset/ (Kustomize)
       ├── akv2k8s.yaml (ApplicationSet)
       ├── adp-agent.yaml (ApplicationSet)
       ├── otel.yaml (ApplicationSet)
       └── ... (curated list in kustomization.yaml)

Quick Reference

• Root Application path: infra-team/bootstrap/root-applicationsets.yaml
• ApplicationSet directory: infra-team/applicationset/
• Kustomization file: infra-team/applicationset/kustomization.yaml
• Values repo: argo-cd-helm-values/kube-addons/{addon}/{cluster}/values.yaml
• Git repo URL: https://your-org@dev.azure.com/your-org/devops-team/_git/argocd

Full documentation: See workflow files in Workflows/ directory.