Add Dockerfile and CI

Add a Dockerfile to build an image for GoAuthing, which can be used to
run the app on a server without configuring systemd or other init
systems (e.g. Some commercial NAS devices may not support systemd).

Add two GitHub Actions jobs to build and push the Docker image to
GitHub Container Registry.

.github/workflows/go.yml

@@ -42,3 +42,22 @@ jobs:
         CGO_ENABLED=0 GOARCH=riscv64 GOOS=linux go build -ldflags="-s -w" -o auth-thu.linux.riscv64 ./cli/main.go
         CGO_ENABLED=0 GOARCH=loong64 GOOS=linux go build -ldflags="-s -w" -o auth-thu.linux.loong64 ./cli/main.go
 
+  build-image:
+    name: Build Docker Image
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v4
+
+    - name: Set up QEMU
+      uses: docker/setup-qemu-action@v3
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v3
+
+    - name: Build the Docker image
+      uses: docker/build-push-action@v5
+      with:
+        push: false
+        context: .

.github/workflows/release.yml

@@ -55,3 +55,41 @@ jobs:
         tag_name="${GITHUB_REF##*/}"
         hub release edit $(find . -type f -executable -name "auth-thu.*" -printf "-a %p ") -m "" "$tag_name" 
 
+  build-image:
+    name: Build Image
+    runs-on: ubuntu-latest
+    needs: build
+    env:
+      REGISTRY: ghcr.io
+      IMAGE_NAME: ${{ github.repository }}
+
+    steps:
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v4
+
+    - name: Set up QEMU
+      uses: docker/setup-qemu-action@v3
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v3
+
+    - name: Log in to the Container Registry
+      uses: docker/login-action@v3
+      with:
+        registry: ${{ env.REGISTRY }}
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Extract metadata
+      id: metadata
+      uses: docker/metadata-action@v5
+      with:
+        images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+    - name: Build and push the Docker image
+      uses: docker/build-push-action@v5
+      with:
+        push: true
+        context: .
+        tags: ${{ steps.metadata.outputs.tags }}
+        labels: ${{ steps.metadata.outputs.labels }}

Dockerfile

@@ -0,0 +1,13 @@
+FROM golang:alpine AS builder
+
+WORKDIR /app
+COPY . .
+
+RUN CGO_ENABLED=0 go build -ldflags="-s -w" -o /app/auth-thu /app/cli/main.go
+
+FROM scratch
+
+COPY --from=builder /app/auth-thu /auth-thu
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
+
+ENTRYPOINT [ "/auth-thu" ]

README.md

@@ -126,6 +126,21 @@ uci commit goauthing
 /etc/init.d/goauthing start
 ```
 
+### Docker
+
+For Docker users, you can run the container with a restart policy. An example docker compose is like this:
+
+```yaml
+services:
+  goauthing:
+    image: ghcr.io/z4yx/goauthing:latest
+    container_name: goauthing
+    restart: always
+    volumes:
+      - /path/to/your/config:/.auth-thu
+   command: auth -k
+```
+
 ## Build
 
 Requires Go 1.11 or above