Add Dockerfile and automated image building (#213)

* Add Dockerfile

* Add Docker build workflow

* Make the image be tagged with commit sha and latest

* Fix naming of builder layer

* Switch to eclipse temurin for run image

* Try using java 22

* nvm 21 it is

* Install git in image

* That wasn't the problem, copy .git now

* Remove chown's cuz not needed

* 17?

* Add newline at the end of docker workflow

* Only build container image on push to main

.github/workflows/build-docker.yml

@@ -0,0 +1,42 @@
+name: build-docker
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+
+env:
+  REGISTRY: ghcr.io
+
+jobs:
+  build:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v4
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Log into registry ${{ env.REGISTRY }}
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          tags: |
+            type=raw,value=latest
+            type=sha
+          images: ${{ env.REGISTRY }}/${{ github.repository }}
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          platforms: linux/amd64,linux/arm64
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

Dockerfile

@@ -0,0 +1,11 @@
+FROM --platform=$BUILDPLATFORM gradle:jdk17 as builder
+WORKDIR /build
+COPY build.gradle settings.gradle gradle.properties ./
+COPY .git .git
+COPY src src
+RUN gradle --no-daemon build
+
+FROM --platform=$TARGETPLATFORM eclipse-temurin:21-jre-alpine
+WORKDIR /app
+COPY --from=builder /build/build/libs/ViaProxy-*.jar ViaProxy.jar
+ENTRYPOINT ["java", "-jar", "ViaProxy.jar"]