added docker workflow

.github/workflows/main.yml

@@ -0,0 +1,41 @@
+name: Build and Publish Docker Container
+
+on:
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: checkout
+        uses: actions/checkout@v3
+
+      - name: Set up JDK 19
+        uses: actions/setup-java@v3
+        with:
+          distribution: corretto
+          java-version: 19
+          cache: 'gradle'
+
+      - name: Setup Gradle
+        uses: gradle/gradle-build-action@v2
+        with:
+          gradle-version: 7.6
+          gradle-home-cache-cleanup: true
+
+      - name: Run build with Gradle wrapper
+        run: ./gradlew shadowJar
+
+      - name: Docker Login
+        uses: docker/login-action@v2
+        with:
+          username: fusseltv
+          password: dckr_pat_uxkzMELfS138kGYEyBYsPjxMF7c
+
+      - name: Build and push
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          push: true
+          tags: fusseltv/gym-webhook:latest

Dockerfile

@@ -0,0 +1,17 @@
+# Use openjdk image version 19 as the base image
+FROM eclipse-temurin:19-jre-alpine
+
+# Update the packages in the image
+RUN apk update && apk upgrade
+
+# Set the working directory
+WORKDIR /app
+
+# Copy the JDA bot code to the working directory
+COPY ./build/libs/StaffWebhook.jar .
+
+# Run the JDA bot jar file, passing in the environment variables as command line arguments
+CMD ["java", "-jar", "StaffWebhook.jar"]
+
+# Set the user and group to non-root
+USER 1001:0