Use buildx to create multi-architecture container images

Author: rjeberhard

.github/workflows/release.yml

@@ -51,16 +51,23 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+
+      - name: Set up Buildx
+        uses: docker/setup-buildx-action@v2
+
       - name: Log in to the Container registry
         uses: docker/login-action@v2
         with:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Build and push Docker image
-        uses: docker/build-push-action@v3
+      - name: Build and push container image
+        uses: docker/build-push-action@v4
         with:
           context: .
+          platforms: linux/amd64,linux/arm64
           push: true
           tags: ${{ env.IMAGE_NAME }}

Dockerfile

@@ -3,10 +3,17 @@
 
 FROM ghcr.io/oracle/oraclelinux:9-slim AS jre-build
 
-ENV JAVA_URL="https://download.java.net/java/GA/jdk19.0.2/fdb695a9d9064ad6b064dc6df578380c/7/GPL/openjdk-19.0.2_linux-x64_bin.tar.gz"
+ENV JAVA_URL_X64="https://download.java.net/java/GA/jdk20/bdc68b4b9cbc4ebcb30745c85038d91d/36/GPL/openjdk-20_linux-x64_bin.tar.gz"
+ENV JAVA_URL_AARCH64="https://download.java.net/java/GA/jdk20/bdc68b4b9cbc4ebcb30745c85038d91d/36/GPL/openjdk-20_linux-aarch64_bin.tar.gz"
 
 RUN set -eux; \
     microdnf -y install gzip tar; \
+    MACHINE_TYPE=`uname -m`; \
+    if [ ${MACHINE_TYPE} == 'x86_64' ]; then \
+      JAVA_URL=$JAVA_URL_X64; \
+    else \
+      JAVA_URL=$JAVA_URL_AARCH64; \
+    fi; \
     curl -fL -o /jdk.tar.gz "$JAVA_URL"; \
     mkdir -p /jdk; \
     tar --extract --file /jdk.tar.gz --directory /jdk --strip-components 1; \