Add GitHub Action for Maven deploy

.github/workflows/maven-build-push.yml

@@ -0,0 +1,57 @@
+# Based on: https://docs.github.com/en/actions/guides/publishing-java-packages-with-maven
+
+# This workflow will build a package using Maven and then publish it to GitHub packages when a release is created
+# For more information see: https://github.com/actions/setup-java/blob/main/docs/advanced-usage.md#apache-maven-with-a-settings-path
+
+name: Maven Deploy
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up JDK 8
+        uses: actions/setup-java@v2
+        with:
+          java-version: '8'
+          distribution: 'adopt'
+          server-id: github # Value of the distributionManagement/repository/id field of the pom.xml
+          settings-path: ${{ github.workspace }} # location for the settings.xml file
+
+      - name: Build with Maven
+        run: mvn --batch-mode package --file pom.xml
+
+      - name: Publish to GitHub Packages Apache Maven
+        run: |
+          # Need to make a dummy call to mvn help:evaluate because first time results in output like:
+          # "Downloading from central: https://repo.maven.apache.org/..."
+          # And later calls to `help:evaluate | grep` are only filtering out lines starting with [.
+          mvn help:evaluate -Dexpression=project.version
+
+          artifactId=$(mvn help:evaluate -Dexpression=project.artifactId | grep -e '^[^\\[]')
+          echo $artifactId
+
+          version=$(mvn help:evaluate -Dexpression=project.version | grep -e '^[^\\[]')
+          echo $version
+
+          # Save the fatjar as the artifact
+          ls -lahFtr target
+          rm target/${artifactId}-${version}.jar
+          mv target/${artifactId}-${version}-fatjar.jar target/${artifactId}-${version}.jar
+          ls -lahFtr target
+
+          # deploy:deploy because only want to deploy and not rebuild
+          # jar:jar because it will populate the build context but not recreate jars
+          # https://stackoverflow.com/questions/6308162/
+          mvn jar:jar deploy:deploy -s $GITHUB_WORKSPACE/settings.xml
+        env:
+          GITHUB_TOKEN: ${{ github.token }}