ci: Create Dockerfile to build a basic container image

.forgejo/workflows/build.yml

@@ -28,5 +28,3 @@ jobs:
       - uses: https://github.com/gradle/actions/setup-gradle@v4
       - name: Build gradle project
         run: ./gradlew build
-        env:
-          ORG_GRADLE_PROJECT_SPRING_DEBUG: ${{ fromJSON(steps.pr-env.outputs.result).SPRING_DEBUG }}

.forgejo/workflows/formatting.yml

@@ -9,6 +9,11 @@ concurrency:
   cancel-in-progress: true
   group: ${{ github.workflow }}-${{ github.ref }}
 
+env:
+  HTTP_PROXY: http://6.fsn1-1.forsaken-ashbirds.net:8888
+  HTTPS_PROXY: http://6.fsn1-1.forsaken-ashbirds.net:8888
+  GRADLE_OPTS: -Dhttp.proxyHost=6.fsn1-1.forsaken-ashbirds.net -Dhttp.proxyPort=8888 -Dhttps.proxyHost=6.fsn1-1.forsaken-ashbirds.net -Dhttps.proxyPort=8888
+
 jobs:
   check-formatting:
     runs-on: ubuntu-24.04

Dockerfile

@@ -0,0 +1,31 @@
+FROM node:22 AS fe-build
+
+RUN mkdir /mnt/workspace
+WORKDIR /mnt/workspace
+
+COPY ./frontend /mnt/workspace
+
+RUN npm install --global pnpm \
+    && pnpm install \
+    && pnpm run build \
+
+FROM gradle AS be-build
+
+RUN mkdir /mnt/workspace
+WORKDIR /mnt/workspace
+
+COPY --exclude=./frontend . ./mnt/workspace
+
+RUN ./gradlew -x test build
+
+FROM eclipse-temurin:21-jre-nanoserver
+
+ENV USE_SYSTEM_CA_CERTS=1
+
+RUN mkdir /opt/home-cert-assistant
+WORKDIR /opt/home-cert-assistant
+
+COPY --from=fe-build /mnt/workspace/dist /opt/home-cert-assistant/frontend
+COPY --from=be-build /mnt/workspace/build/home-cert-assistant-0.0.1-SNAPSHOT.jar /opt/home-cert-assistant/
+
+CMD ["java", "-jar", "/opt/home-cert-assistant/.jar"]