managing-k8s-argocd-deep

name	managing-k8s-argocd-deep
description	Use when working with K8S Argocd Deep — argoCD deep-dive management for advanced GitOps operations. Covers ApplicationSet controllers, multi-cluster sync strategies, notification configurations, resource hook analysis, sync wave ordering, application health aggregation, image updater integration, and RBAC policy auditing. Use when debugging complex sync failures, analyzing multi-cluster deployments, or optimizing ArgoCD performance at scale.
connection_type	k8s
preload	false

ArgoCD Deep-Dive Skill

Advanced analysis of ArgoCD GitOps deployments, ApplicationSets, and multi-cluster management.

MANDATORY: Discovery-First Pattern

Always check ArgoCD component health and application inventory before deep-diving.

Phase 1: Discovery

#!/bin/bash

echo "=== ArgoCD Components ==="
kubectl get deployment -n argocd -o custom-columns='NAME:.metadata.name,READY:.status.readyReplicas,IMAGE:.spec.template.spec.containers[0].image' 2>/dev/null

echo ""
echo "=== ArgoCD Server Version ==="
kubectl get configmap argocd-cm -n argocd -o jsonpath='{.metadata.labels.app\.kubernetes\.io/version}' 2>/dev/null
echo ""

echo ""
echo "=== Applications Summary ==="
kubectl get applications -n argocd -o custom-columns='NAME:.metadata.name,SYNC:.status.sync.status,HEALTH:.status.health.status,DEST-NS:.spec.destination.namespace,PROJECT:.spec.project' 2>/dev/null | head -20

echo ""
echo "=== ApplicationSets ==="
kubectl get applicationsets -n argocd -o custom-columns='NAME:.metadata.name,GENERATORS:.spec.generators[*]' 2>/dev/null | head -15

echo ""
echo "=== AppProjects ==="
kubectl get appprojects -n argocd -o custom-columns='NAME:.metadata.name,SOURCE-REPOS:.spec.sourceRepos[0],DESTINATIONS:.spec.destinations[*].namespace' 2>/dev/null | head -10

Phase 2: Analysis

#!/bin/bash

echo "=== Unhealthy Applications ==="
kubectl get applications -n argocd -o json 2>/dev/null | jq -r '
  .items[] |
  select(.status.health.status != "Healthy" or .status.sync.status != "Synced") |
  "\(.metadata.name)\tSync:\(.status.sync.status)\tHealth:\(.status.health.status)"
' | head -15

echo ""
echo "=== Sync Errors ==="
kubectl get applications -n argocd -o json 2>/dev/null | jq -r '
  .items[] |
  select(.status.conditions != null) |
  .status.conditions[] |
  "\(.type)\t\(.message[0:100])"
' | head -15

echo ""
echo "=== Resource Hooks ==="
kubectl get applications -n argocd -o json 2>/dev/null | jq -r '
  .items[] |
  select(.status.operationState.syncResult.resources != null) |
  .status.operationState.syncResult.resources[] |
  select(.hook == true) |
  "\(.kind)/\(.name)\tPhase:\(.hookPhase)\tStatus:\(.status)"
' | head -10

echo ""
echo "=== ApplicationSet Generator Status ==="
kubectl get applicationsets -n argocd -o json 2>/dev/null | jq -r '
  .items[] |
  "\(.metadata.name)\tGenerators:\([.spec.generators[].type // keys[0]] | join(","))\tApps:\(.status.conditions[0].message // "unknown")"
' | head -10

echo ""
echo "=== Image Updater (if installed) ==="
kubectl get deployment argocd-image-updater -n argocd -o custom-columns='NAME:.metadata.name,READY:.status.readyReplicas' 2>/dev/null
kubectl get applications -n argocd -o json 2>/dev/null | jq -r '
  .items[] |
  select(.metadata.annotations["argocd-image-updater.argoproj.io/image-list"] // "" != "") |
  "\(.metadata.name)\tImages:\(.metadata.annotations["argocd-image-updater.argoproj.io/image-list"])"
' | head -10

echo ""
 
kubectl get configmap argocd-notifications-cm -n argocd -o jsonpath= 2>/dev/null | jq -r  |  -10

 
 
kubectl get configmap argocd-rbac-cm -n argocd -o jsonpath= 2>/dev/null |  -10

 
 
kubectl logs deployment/argocd-application-controller -n argocd --=20 2>/dev/null | grep -i  |  -10

Output Format

• Target ≤50 lines per output
• Use -o custom-columns for Application listings
• Show sync/health status matrix for quick overview
• Aggregate ApplicationSet-generated apps by set name
• Never dump full Application manifests -- show status and source references only

Anti-Hallucination Rules

1. NEVER assume resource names — always discover via CLI/API in Phase 1 before referencing in Phase 2.
2. NEVER fabricate metric names or dimensions — verify against the service documentation or --help output.
3. NEVER mix CLI commands between service versions — confirm which version/API you are targeting.
4. ALWAYS use the discovery → verify → analyze chain — every resource referenced must have been discovered first.
5. ALWAYS handle empty results gracefully — an empty response is valid data, not an error to retry.

Counter-Rationalizations

Shortcut	Counter	Why
"I'll skip discovery and check known resources"	Always run Phase 1 discovery first	Resource names change, new resources appear — assumed names cause errors
"The user only asked for a quick check"	Follow the full discovery → analysis flow	Quick checks miss critical issues; structured analysis catches silent failures
"Default configuration is probably fine"	Audit configuration explicitly	Defaults often leave logging, security, and optimization features disabled
"Metrics aren't needed for this"	Always check relevant metrics when available	API/CLI responses show current state; metrics reveal trends and intermittent issues
"I don't have access to that"	Try the command and report the actual error	Assumed permission failures prevent useful investigation; actual errors are informative

Common Pitfalls

• Sync waves: Resources with argocd.argoproj.io/sync-wave are applied in order -- failed early waves block later ones
• ApplicationSet generators: Git, List, Cluster, Matrix, Merge generators have different refresh behaviors
• Resource tracking: argocd.argoproj.io/tracking-method annotation controls label vs annotation tracking
• Diff customization: ignoreDifferences in Application spec prevents false OutOfSync on dynamic fields
• Server-side apply: Enable for large resources or CRDs that exceed client-side apply limits
• Sharding: Large installations need controller sharding -- check --application-controller-shard settings
• Notification templates: Template errors silently fail -- test with argocd admin notifications CLI
• Image updater: Writes back to Git or uses parameter overrides -- check write-back method configuration
• Orphaned resources: Enabled via AppProject orphanedResources -- can cause unexpected warnings