build(ci): improve caching efficiency in ci

.gitea/workflows/ci.yml

@@ -53,6 +53,8 @@ jobs:
           file: src/main/Dockerfile
           push: true
           tags: ${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-backend:latest
+          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-backend:buildcache
+          cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_PREFIX }}-backend:buildcache,mode=max
 
       - name: Build and push frontend image
         uses: https://github.com/docker/build-push-action@v6
@@ -73,7 +75,7 @@ jobs:
   deploy:
     name: Deploy to server
     needs: build-and-push
-    if: github.ref == 'refs/heads/master'
+    if: gitea.ref == 'refs/heads/master'
     runs-on: ubuntu-latest
 
     steps:

src/main/Dockerfile

@@ -2,19 +2,17 @@
 FROM maven:3.9.6-eclipse-temurin-21 AS builder
 WORKDIR /app
 COPY pom.xml .
+RUN --mount=type=cache,target=/root/.m2 mvn dependency:go-offline -B
 COPY src ./src
-RUN mvn clean package -DskipTests
-
+RUN --mount=type=cache,target=/root/.m2 mvn clean package -DskipTests -B
 
 # Run stage
-FROM eclipse-temurin:21-jdk
-
+FROM eclipse-temurin:21-jre
 # dependencies
 RUN apt-get update && \
-    apt-get install -y ffmpeg && \
+    apt-get install -y --no-install-recommends ffmpeg && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/*
-
 WORKDIR /app
 COPY --from=builder /app/target/*.jar app.jar
 EXPOSE 8080