ci: temporarily revert runners to public images to bootstrap custom image build

## Problem

Init container skips registration if `.runner` file exists on PVC:
```
test -f /data/.runner || forgejo-runner register ...
```

This means changing runner labels in `values.yaml` (e.g. the label image fix from PR #1) has **no effect** until PVCs are manually deleted — not GitOps-friendly.

## Fix

Always delete `.runner` and re-register on every pod start:
```
rm -f /data/.runner
forgejo-runner register --no-interactive ...
```

Labels now stay in sync with `values.yaml` automatically. ArgoCD syncs → pods restart → init re-registers with current labels.

## Files Changed

- `k8s/infra/forgejo-runner/templates/deployment.yaml` (init container logic)

## After Merge

ArgoCD syncs → deployment spec changes → pods restart → init re-registers with new labels from PR #1 → CI works across all repos.Reviewed-on: rock/homelab#2

Co-authored-by: rock <[email protected]>

.gitea/workflows/build-runner-images.yml

@@ -0,0 +1,93 @@
+name: Build & Push Runner Images
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:  # Manual trigger
+  schedule:
+    - cron: '0 2 * * 0'  # Weekly on Sunday 2 AM UTC (ensure fresh images)
+
+env:
+  REGISTRY: forgejo.riotpiao.com
+
+jobs:
+  build-runner-images:
+    name: Build & Push All Runner Images
+    runs-on: golang
+    steps:
+      - name: Install Node.js and Docker
+        run: |
+          apt-get update
+          apt-get install -y nodejs docker.io
+
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Get short SHA
+        id: sha
+        run: |
+          SHORT_SHA=$(git rev-parse --short HEAD)
+          echo "short_sha=${SHORT_SHA}" >> $GITHUB_OUTPUT
+
+      - name: Registry login
+        run: |
+          echo "${REGISTRY_TOKEN}" | docker login "${REGISTRY}" \
+            --username "${REGISTRY_USER}" --password-stdin
+        env:
+          REGISTRY_USER: ${{ secrets.FORGEJO_REGISTRY_USER }}
+          REGISTRY_TOKEN: ${{ secrets.FORGEJO_REGISTRY_TOKEN }}
+
+      - name: Build and push Golang runner image
+        run: |
+          IMAGE="${REGISTRY}/rock/forgejo-runner-golang"
+          echo "Building: ${IMAGE}:${{ steps.sha.outputs.short_sha }}"
+          
+          docker build --no-cache \
+            -f k8s/infra/forgejo-runner-images/Dockerfile.golang \
+            -t "${IMAGE}:${{ steps.sha.outputs.short_sha }}" \
+            -t "${IMAGE}:latest" \
+            .
+          
+          docker push "${IMAGE}:${{ steps.sha.outputs.short_sha }}"
+          docker push "${IMAGE}:latest"
+          echo "✓ Pushed golang runner"
+
+      - name: Build and push Node runner image
+        run: |
+          IMAGE="${REGISTRY}/rock/forgejo-runner-node"
+          echo "Building: ${IMAGE}:${{ steps.sha.outputs.short_sha }}"
+          
+          docker build --no-cache \
+            -f k8s/infra/forgejo-runner-images/Dockerfile.node \
+            -t "${IMAGE}:${{ steps.sha.outputs.short_sha }}" \
+            -t "${IMAGE}:latest" \
+            .
+          
+          docker push "${IMAGE}:${{ steps.sha.outputs.short_sha }}"
+          docker push "${IMAGE}:latest"
+          echo "✓ Pushed node runner"
+
+      - name: Build and push Rust runner image
+        run: |
+          IMAGE="${REGISTRY}/rock/forgejo-runner-rust"
+          echo "Building: ${IMAGE}:${{ steps.sha.outputs.short_sha }}"
+          
+          docker build --no-cache \
+            -f k8s/infra/forgejo-runner-images/Dockerfile.rust \
+            -t "${IMAGE}:${{ steps.sha.outputs.short_sha }}" \
+            -t "${IMAGE}:latest" \
+            .
+          
+          docker push "${IMAGE}:${{ steps.sha.outputs.short_sha }}"
+          docker push "${IMAGE}:latest"
+          echo "✓ Pushed rust runner"
+
+      - name: Prune unused images
+        run: docker image prune -a --force 2>&1 | tail -3 || true
+
+      - name: Summary
+        run: |
+          echo "=== Runner Images Built and Pushed ===" 
+          echo "✓ forgejo.riotpiao.com/rock/forgejo-runner-golang:latest"
+          echo "✓ forgejo.riotpiao.com/rock/forgejo-runner-node:latest"
+          echo "✓ forgejo.riotpiao.com/rock/forgejo-runner-rust:latest"

CLAUDE.example.md

@@ -208,3 +208,95 @@ versions without warning in your own values file.
 Grouping by layer (rather than by day or by "misc fixes") makes it much
 easier to `git log --oneline -- <path>` your way back to *why* a given
 piece of config looks the way it does, months later.
+
+## Unified Forgejo CI Workflow Pattern (Enforced 2026-09-07+)
+
+All repositories MUST follow this exact structure. No variations.
+
+```yaml
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+env:
+  REGISTRY: <your-registry-hostname>
+  IMAGE: <registry>/<org>/<service-name>
+
+jobs:
+  test:
+    name: Test
+    runs-on: [golang|node|rust]
+    steps:
+      - name: Install Node.js for actions runtime
+        run: apt-get update && apt-get install -y nodejs
+
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      # Language-specific tests here (no docker, no registry)
+      # - name: Run tests
+      #   run: npm test -- --run || true
+
+  build-push:
+    name: Build & Push Image
+    needs: test
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    runs-on: [golang|node|rust]
+    steps:
+      - name: Install Node.js and Docker
+        run: |
+          apt-get update
+          apt-get install -y nodejs docker.io
+
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Get short SHA
+        id: sha
+        run: |
+          SHORT_SHA=$(git rev-parse --short HEAD)
+          echo "short_sha=${SHORT_SHA}" >> $GITHUB_OUTPUT
+
+      - name: Registry login
+        run: |
+          echo "${REGISTRY_TOKEN}" | docker login "${REGISTRY}" \
+            --username "${REGISTRY_USER}" --password-stdin
+        env:
+          REGISTRY_USER: ${{ secrets.FORGEJO_REGISTRY_USER }}
+          REGISTRY_TOKEN: ${{ secrets.FORGEJO_REGISTRY_TOKEN }}
+
+      - name: Build Docker image
+        run: |
+          docker build --no-cache \
+            -t "${IMAGE}:${{ steps.sha.outputs.short_sha }}" \
+            -t "${IMAGE}:latest" \
+            .
+
+      - name: Push Docker image
+        run: |
+          docker push "${IMAGE}:${{ steps.sha.outputs.short_sha }}"
+          docker push "${IMAGE}:latest"
+
+      - name: Prune unused images
+        run: docker image prune -a --force 2>&1 | tail -3 || true
+```
+
+### Anti-Patterns (DO NOT USE)
+
+- ❌ `container: image: golang:1.26` overrides — breaks docker socket sharing
+- ❌ Conditional `if:` on individual steps — use separate jobs instead
+- ❌ Installing docker.io in test job — only needed in build-push
+- ❌ Monolithic job doing test + build + push — hard to debug
+- ❌ Using `{{ github.sha }}` for image tag — use short commit SHA for readability
+
+### How It Works
+
+1. **PR to feature branch** → test job runs, build-push skipped, nothing pushed
+2. **Push to main** → test runs, build-push runs after test passes, image pushed
+3. Docker socket shared between dind sidecar and runner via emptyDir mount at `/run`
+4. `docker_host: automount` in runner config injects socket into workflow containers
+5. Secrets (FORGEJO_REGISTRY_USER, TOKEN) set in Forgejo repo settings, NOT in git

k8s/infra/forgejo-runner-images/Dockerfile.golang

@@ -0,0 +1,12 @@
+FROM golang:1.26-bookworm
+
+# Install Node.js, npm, and Docker CLI
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    nodejs npm docker.io \
+    && rm -rf /var/lib/apt/lists/*
+
+# Verify installations
+RUN go version && node --version && npm --version && docker --version
+
+LABEL maintainer="homelab" \
+      description="Golang 1.26 + Node.js + Docker CLI pre-installed"

k8s/infra/forgejo-runner-images/Dockerfile.node

@@ -0,0 +1,12 @@
+FROM node:22-bookworm
+
+# Node.js already installed, add Docker CLI
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    docker.io \
+    && rm -rf /var/lib/apt/lists/*
+
+# Verify installations
+RUN node --version && npm --version && docker --version
+
+LABEL maintainer="homelab" \
+      description="Node.js 22 + Docker CLI pre-installed"

k8s/infra/forgejo-runner-images/Dockerfile.rust

@@ -0,0 +1,12 @@
+FROM rust:1-bookworm
+
+# Add Node.js and Docker CLI
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    nodejs npm docker.io \
+    && rm -rf /var/lib/apt/lists/*
+
+# Verify installations
+RUN rustc --version && cargo --version && node --version && npm --version && docker --version
+
+LABEL maintainer="homelab" \
+      description="Rust 1 + Node.js + Docker CLI pre-installed"

k8s/infra/forgejo-runner/values.yaml

@@ -5,7 +5,7 @@ runner:
   name: golang-runner
   # Label image is what workflow steps run in (NOT the runner daemon image).
   # golang:1.26-bookworm: Debian, root, apt-get, Go, git.
-  # Install Node.js/docker in workflow steps as needed.
+  # TODO: Switch to custom image once build-runner-images.yml pushes images
   labels: "golang:docker://golang:1.26-bookworm"
   forgejoUrl: http://forgejo-gitea-http.cicd.svc.cluster.local:3000
   tokenSecret: runner-token