ci: add Dockerfile and ghcr upload workflow

Author: matthiasemde

.github/workflows/docker.yml

@@ -0,0 +1,55 @@
+name: Build and Push Docker Images
+
+on:
+  workflow_dispatch:
+  release:
+    types: [published]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=raw,value=latest
+
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          platforms: linux/amd64, linux/arm64
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          build-args: |
+            VERSION=${{ github.ref_name }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

Dockerfile

@@ -0,0 +1,33 @@
+FROM node:16-alpine AS map-builder
+WORKDIR /build
+COPY map/package*.json ./
+RUN npm install
+COPY map/ ./
+RUN npm run compile
+
+FROM golang:1.25.4-alpine AS go-builder
+WORKDIR /build
+COPY Companion/go.* ./
+RUN go mod download
+COPY Companion/ ./
+ARG VERSION=dev
+RUN CGO_ENABLED=0 go build -ldflags="-X 'main.Version=${VERSION}'" -o companion main.go
+
+FROM alpine:latest
+ARG PROMETHEUS_VERSION=2.27.1
+ARG TARGETARCH
+WORKDIR /app
+
+RUN apk --no-cache add curl tar && \
+    curl -sL https://github.com/prometheus/prometheus/releases/download/v${PROMETHEUS_VERSION}/prometheus-${PROMETHEUS_VERSION}.linux-${TARGETARCH}.tar.gz | tar xz && \
+    mv prometheus-${PROMETHEUS_VERSION}.linux-${TARGETARCH} prometheus && \
+    apk del curl tar
+
+COPY --from=go-builder /build/companion /app/
+COPY --from=map-builder /build/index.html /build/map-16k.png /build/vendor /build/img /build/js /app/map/
+COPY Companion/prometheus.yml /app/prometheus/prometheus.yml
+
+ENV FRM_LOG_STDOUT=true
+EXPOSE 9000
+
+CMD ["/app/companion"]