⚡ 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:

Dockerfile.build

@@ -0,0 +1,39 @@
+# Build environment Dockerfile with pre-installed Go tools and dependencies
+# Optimized for CI/CD pipeline speed
+
+FROM golang:1.26.1-alpine AS builder
+
+# Install build dependencies
+RUN apk add --no-cache \
+    git \
+    bash \
+    curl \
+    make \
+    gcc \
+    musl-dev \
+    bc \
+    grep \
+    sed \
+    jq \
+    ca-certificates
+
+# Set up Go environment
+ENV GOPATH=/go
+ENV PATH=$GOPATH/bin:/usr/local/go/bin:/usr/local/bin:/usr/bin:/bin
+WORKDIR /go/src/dance-lessons-coach
+
+# Install common Go tools
+RUN go install github.com/swaggo/swag/cmd/swag@latest && \
+    go install golang.org/x/tools/cmd/goimports@latest && \
+    go install honnef.co/go/tools/cmd/staticcheck@latest
+
+# Copy only go.mod and go.sum first for dependency caching
+COPY go.mod go.sum ./
+RUN go mod download && go mod verify
+
+# Copy the rest of the source (this happens in CI)
+# COPY . .
+
+# Build command (will be run in CI)
+# RUN go build -o /out/server ./cmd/server && \
+#     go build -o /out/greet ./cmd/greet

scripts/ci-calculate-deps-hash.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+# Calculate hash for go.mod + go.sum to use as Docker tag
+# Usage: scripts/ci-calculate-deps-hash.sh
+
+set -e
+
+# Calculate SHA256 hash of go.mod and go.sum combined
+DEPS_HASH=$(sha256sum go.mod go.sum | sha256sum | cut -d' ' -f1 | head -c 12)
+echo "Dependency hash: $DEPS_HASH"
+echo "$DEPS_HASH" > .deps_hash
+
+echo "::set-output name=deps_hash::$DEPS_HASH"