Add docker file and github workflow to publish to ghcr.io

.github/workflows/docker-publish.yml

@@ -0,0 +1,41 @@
+name: Create and publish a Docker image
+
+on:
+  release:
+    types: [published]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@v1
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v3
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Dockerfile

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+FROM golang:alpine
+
+WORKDIR /app
+
+# Download necessary Go modules
+COPY go.mod .
+COPY go.sum .
+RUN go mod download
+
+# Copy files and build
+COPY *.go .
+RUN go build -o /mirth_channel_exporter
+
+# Runtime
+EXPOSE 8080
+CMD [ "/mirth_channel_exporter" ]