⚡ feat: implement Docker build cache for CI acceleration

.gitea/workflows/ci-cd.yaml

@@ -57,8 +57,69 @@ env:
   CI_REGISTRY: "gitea.arcodange.lab"
 
 jobs:
+  build-cache:
+    name: Build Docker Cache
+    runs-on: ubuntu-latest
+    if: "!contains(github.event.head_commit.message, '[skip ci]') && github.actor != 'ci-bot'"
+    outputs:
+      deps_hash: ${{ steps.calculate_hash.outputs.deps_hash }}
+      cache_hit: ${{ steps.check_cache.outputs.cache_hit }}
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Calculate dependency hash
+        id: calculate_hash
+        run: |
+          # Calculate hash of go.mod + go.sum
+          DEPS_HASH=$(sha256sum go.mod go.sum | sha256sum | cut -d' ' -f1 | head -c 12)
+          echo "Dependency hash: $DEPS_HASH"
+          echo "deps_hash=$DEPS_HASH" >> $GITHUB_OUTPUT
+
+      - name: Check for existing cache
+        id: check_cache
+        run: |
+          # Check if image exists in registry
+          IMAGE_NAME="${{ env.CI_REGISTRY }}/${{ env.GITEA_ORG }}/${{ env.GITEA_REPO }}-build-cache:${{ steps.calculate_hash.outputs.deps_hash }}"
+          
+          # Try to pull the image to see if it exists
+          if docker pull "$IMAGE_NAME" >/dev/null 2>&1; then
+            echo "✅ Cache hit - using existing build cache"
+            echo "cache_hit=true" >> $GITHUB_OUTPUT
+          else
+            echo "⚠️  Cache miss - will build new cache image"
+            echo "cache_hit=false" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Login to Gitea Container Registry
+        if: steps.check_cache.outputs.cache_hit == 'false'
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.CI_REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.PACKAGES_TOKEN }}
+
+      - name: Set up Docker Buildx
+        if: steps.check_cache.outputs.cache_hit == 'false'
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build and push Docker cache image
+        if: steps.check_cache.outputs.cache_hit == 'false'
+        run: |
+          IMAGE_NAME="${{ env.CI_REGISTRY }}/${{ env.GITEA_ORG }}/${{ env.GITEA_REPO }}-build-cache:${{ steps.calculate_hash.outputs.deps_hash }}"
+          echo "Building cache image: $IMAGE_NAME"
+          
+          docker buildx build \
+            --file Dockerfile.build \
+            --tag "$IMAGE_NAME" \
+            --push \
+            .
+
+          echo "✅ Build cache image pushed successfully"
+
   ci-pipeline:
     name: CI Pipeline
+    needs: build-cache
     runs-on: ubuntu-latest
     if: "!contains(github.event.head_commit.message, '[skip ci]') && github.actor != 'ci-bot'"
     
@@ -66,6 +127,22 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Gitea Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.CI_REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.PACKAGES_TOKEN }}
+
+      - name: Pull Docker build cache
+        run: |
+          IMAGE_NAME="${{ env.CI_REGISTRY }}/${{ env.GITEA_ORG }}/${{ env.GITEA_REPO }}-build-cache:${{ needs.build-cache.outputs.deps_hash }}"
+          echo "Using build cache image: $IMAGE_NAME"
+          docker pull "$IMAGE_NAME" || echo "Cache pull failed, will use regular setup"
+
       - name: Set up Go
         uses: actions/setup-go@v4
         with: