app set

APPLICATIONSET_GUIDE.md

@@ -0,0 +1,290 @@
+# ApplicationSet Guide
+
+## Overview
+
+This repository uses **ApplicationSet** (instead of the traditional app-of-apps pattern) to manage infrastructure applications. ApplicationSet automatically discovers and creates ArgoCD Applications based on a git directory pattern.
+
+## How It Works
+
+### ApplicationSet Definition
+Located in `argocd/_app-of-apps.yaml`:
+
+```yaml
+apiVersion: argoproj.io/v1alpha1
+kind: ApplicationSet
+metadata:
+  name: infrastructure-apps
+  namespace: argocd
+spec:
+  goTemplate: true
+  generators:
+  - git:
+      repoURL: https://github.com/fortedigital/sturdy-adventure.git
+      revision: HEAD
+      directories:
+      - path: argocd/infra/*.yaml
+  template:
+    # Template applied to each discovered file
+```
+
+### Key Components
+
+1. **Generator**: Scans `argocd/infra/*.yaml` for all Application manifests
+2. **Path Variables**: Each match provides template variables:
+   - `{{ .path.basenameNormalized }}` - filename without extension (e.g., "prometheus")
+   - `{{ .path.dir }}` - directory path (e.g., "argocd/infra")
+3. **Template**: Used to create consistent Applications from the discovered files
+
+## How Applications Are Created
+
+When you create a new file `argocd/infra/my-app.yaml`:
+
+```yaml
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: my-app
+  # ... other config
+spec:
+  # ... your application spec
+```
+
+The ApplicationSet:
+1. Discovers the file matching `argocd/infra/*.yaml`
+2. Extracts metadata: `basenameNormalized=my-app`, `dir=argocd/infra`
+3. Renders the template with these variables
+4. Creates an Application resource with:
+   - Name: `my-app`
+   - Labels applied from the template
+   - Sync policy inherited from template
+   - Source path: `argocd/infra`
+
+## Adding New Applications
+
+### Step 1: Create Application YAML
+Create `argocd/infra/my-new-app.yaml`:
+
+```yaml
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: my-new-app
+  annotations:
+    argocd.argoproj.io/sync-wave: "2"  # Optional: control sync ordering
+spec:
+  project: default
+  source:
+    repoURL: https://my-helm-repo.com
+    chart: my-chart
+    targetRevision: "1.0.0"
+    helm:
+      releaseName: my-new-app
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: my-namespace
+  # Note: syncPolicy is applied from the ApplicationSet template
+  # No need to duplicate it here
+```
+
+### Step 2: Push to Repository
+```bash
+git add argocd/infra/my-new-app.yaml
+git commit -m "Add my-new-app infrastructure application"
+git push
+```
+
+### Step 3: Verify Discovery
+```bash
+# View all generated applications
+kubectl get applications -n argocd
+
+# Check ApplicationSet status
+kubectl describe applicationset infrastructure-apps -n argocd
+
+# Watch for your new application
+kubectl get application my-new-app -n argocd -w
+```
+
+## Template Variables
+
+The ApplicationSet template uses these variables for each discovered file:
+
+| Variable | Example | Description |
+|----------|---------|-------------|
+| `{{ .path.basenameNormalized }}` | `prometheus` | Filename without extension |
+| `{{ .path.dir }}` | `argocd/infra` | Directory containing the file |
+| `{{ .path.path }}` | `argocd/infra/prometheus.yaml` | Full path to the file |
+
+## ApplicationSet Features Used
+
+### 1. Git Directory Generator
+```yaml
+generators:
+- git:
+    repoURL: https://github.com/fortedigital/sturdy-adventure.git
+    revision: HEAD
+    directories:
+    - path: argocd/infra/*.yaml  # Match all YAML files
+```
+
+Automatically discovers applications in the git repository.
+
+### 2. Go Templating
+```yaml
+goTemplate: true
+```
+
+Enables Go template syntax for variable interpolation (e.g., `{{ .path.basenameNormalized }}`).
+
+### 3. Dynamic Application Generation
+```yaml
+template:
+  metadata:
+    name: "{{ .path.basenameNormalized }}"
+    labels:
+      app.kubernetes.io/name: "{{ .path.basenameNormalized }}"
+```
+
+Each discovered file generates an Application with consistent configuration.
+
+## Benefits Over App-of-Apps Pattern
+
+| Feature | ApplicationSet | App-of-Apps |
+|---------|---|---|
+| Auto-discovery | ✅ Automatic | ❌ Manual list required |
+| New app onboarding | 1 file created | 1 file created + parent update |
+| Consistency | ✅ Template enforced | ❌ Manual consistency |
+| Scalability | ✅ Grows automatically | ❌ Manual maintenance |
+| RBAC per app | ✅ Supported | ❌ Limited |
+| Drift detection | ✅ Per app | ✅ Per app |
+
+## Sync Policy Applied by ApplicationSet
+
+All generated Applications inherit this sync policy from the template:
+
+```yaml
+syncPolicy:
+  automated:
+    prune: true
+    selfHeal: true
+  syncOptions:
+  - CreateNamespace=true
+  - Validate=true
+  - ServerSideApply=true
+  timeout: 300s
+  retry:
+    limit: 5
+    backoff:
+      duration: 5s
+      factor: 2
+      maxDuration: 3m
+```
+
+**What this means:**
+- ✅ Automatic syncing when repository changes
+- ✅ Automatic pruning of deleted resources
+- ✅ Self-healing if cluster drifts from git
+- ✅ Namespace auto-creation if missing
+- ✅ Manifest validation before applying
+- ✅ Server-side apply for field ownership
+- ✅ 5-minute timeout per application sync
+- ✅ Up to 5 retry attempts with exponential backoff
+
+## Monitoring ApplicationSet
+
+### View ApplicationSet Status
+```bash
+kubectl describe applicationset infrastructure-apps -n argocd
+```
+
+Output shows:
+- Condition status (Healthy, Progressing, etc.)
+- Number of applications created
+- Last sync time
+- Error messages if any
+
+### View Generated Applications
+```bash
+# All applications created by this ApplicationSet
+kubectl get applications -n argocd -l app.kubernetes.io/managed-by=argocd
+
+# View a specific application
+kubectl get application prometheus -n argocd -o yaml
+```
+
+### Check Sync Status
+```bash
+# Watch all applications
+kubectl get applications -n argocd -w
+
+# Detailed sync status
+argocd app list
+
+# Application health
+kubectl get applications -n argocd -o wide
+```
+
+## Troubleshooting
+
+### ApplicationSet Not Creating Applications
+
+**Problem**: Files in `argocd/infra/` but no Applications created
+
+**Solutions**:
+1. Check file naming: Must end with `.yaml` (not `.yml`)
+2. Verify path: Files must be in `argocd/infra/` (not subdirectories)
+3. Check permissions: Repository URL must be accessible
+4. Review ApplicationSet status: `kubectl describe applicationset infrastructure-apps -n argocd`
+
+### Application Created But Not Syncing
+
+**Problem**: Application exists but stays in "OutOfSync" state
+
+**Solutions**:
+1. Check application spec is valid YAML
+2. Verify `destination.server` is accessible: `https://kubernetes.default.svc`
+3. Check `destination.namespace` exists or `CreateNamespace=true` is set
+4. Review application logs: `kubectl logs -n argocd deployment/argocd-application-controller`
+
+### ApplicationSet Generates Duplicate Applications
+
+**Problem**: Same application created multiple times
+
+**Solutions**:
+1. Check for duplicate files in `argocd/infra/` with same name
+2. Clear git cache: `git clean -fd`
+3. ApplicationSet may take time to reconcile; wait 60 seconds
+
+## Best Practices
+
+1. **File Organization**
+   - Keep only Application manifests in `argocd/infra/`
+   - Don't mix other resource types (ConfigMaps, Secrets, etc.)
+   - Use consistent naming: `lowercase-with-hyphens.yaml`
+
+2. **Application Design**
+   - Keep each Application spec in the discovered file
+   - Don't rely on syncPolicy being defined in the Application (it comes from ApplicationSet)
+   - Use sync waves for dependency ordering
+
+3. **Repository Management**
+   - All files in `argocd/infra/` should be valid Kubernetes manifests
+   - Regular commits to track changes
+   - Use branches for testing new applications before merging
+
+4. **Monitoring**
+   - Regularly check ApplicationSet status
+   - Monitor generated applications for sync status
+   - Set up alerts for Failed or Degraded applications
+
+5. **Updates**
+   - Update application specs directly in `argocd/infra/` files
+   - ApplicationSet changes take effect within 60 seconds
+   - Test in dev environment first
+
+## Related Documentation
+
+- [ArgoCD ApplicationSet Docs](https://argocd-applicationset.readthedocs.io/)
+- [ArgoCD Application Spec](https://argo-cd.readthedocs.io/en/stable/operator-manual/declarative-setup/#applications)
+- [Kubernetes Application Convention](https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#recommended-labels)
+

argocd/_app-of-apps.yaml

@@ -1,26 +1,44 @@
 apiVersion: argoproj.io/v1alpha1
-kind: Application
+kind: ApplicationSet
 metadata:
-  name: app-of-apps
+  name: infrastructure-apps
   namespace: argocd
-  labels:
-    scope: infra
 spec:
-  project: default
+  goTemplate: true
-  source:
+  generators:
-    repoURL: https://github.com/fortedigital/sturdy-adventure.git
+  - git:
-    targetRevision: HEAD
+      repoURL: https://github.com/fortedigital/sturdy-adventure.git
-    path: argocd
+      revision: HEAD
-    directory:
+      directories:
-      recurse: true
+      - path: argocd/infra/*.yaml
-  destination:
+  template:
-    server: https://kubernetes.default.svc
+    metadata:
-    namespace: argocd
+      name: "{{ .path.basenameNormalized }}"
-  syncPolicy:
+      labels:
-    automated:
+        app.kubernetes.io/name: "{{ .path.basenameNormalized }}"
-      prune: true
+        app.kubernetes.io/part-of: platform
-      selfHeal: true
+        app.kubernetes.io/managed-by: argocd
-    syncOptions:
+    spec:
-    - CreateNamespace=true
+      project: default
-    - Validate=true
+      source:
-    - ServerSideApply=true
+        repoURL: https://github.com/fortedigital/sturdy-adventure.git
+        targetRevision: HEAD
+        path: "{{ .path.dir }}"
+      destination:
+        server: https://kubernetes.default.svc
+        namespace: argocd
+      syncPolicy:
+        automated:
+          prune: true
+          selfHeal: true
+        syncOptions:
+        - CreateNamespace=true
+        - Validate=true
+        - ServerSideApply=true
+        timeout: 300s
+        retry:
+          limit: 5
+          backoff:
+            duration: 5s
+            factor: 2
+            maxDuration: 3m

bootstrap.sh

@@ -36,7 +36,7 @@ ArgoCd()
     helm upgrade --install argocd argo-cd \
             --repo https://argoproj.github.io/argo-helm \
             --namespace argocd --create-namespace \
-            --values argocd-values.yaml \
+            --values argocd/values/argocd-values.yaml \
             --timeout 60s --atomic
 }