Added a simple container image

.github/workflows/package.yaml

@@ -0,0 +1,43 @@
+name: Package
+
+on:
+  push:
+    branches:
+      - 'main'
+    tags:
+      - '*'
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@v4
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - uses: docker/login-action@v2
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - uses: docker/setup-buildx-action@v2
+
+      - uses: docker/build-push-action@v3
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -0,0 +1,27 @@
+ARG GOLANG_VERSION=1.18
+ARG ALPINE_VERSION=3.17
+
+FROM golang:${GOLANG_VERSION}-alpine${ALPINE_VERSION} AS build_deps
+
+RUN apk add --no-cache git
+
+WORKDIR /workspace
+
+COPY go.mod .
+COPY go.sum .
+
+RUN go mod download
+
+FROM build_deps AS build
+
+COPY . .
+
+RUN CGO_ENABLED=0 go build -o mqtt2cmd -ldflags '-w -extldflags "-static"' .
+
+FROM alpine:${ALPINE_VERSION}
+
+RUN apk add --no-cache ca-certificates
+
+COPY --from=build /workspace/mqtt2cmd /usr/local/bin/mqtt2cmd
+
+ENTRYPOINT ["/usr/local/bin/mqtt2cmd"]