Docker (#77)

* add dockerfile

* [wip] add cd(image to github packages)

* modify cd

* modify readme

.github/workflows/cd.yaml

@@ -3,6 +3,11 @@ on:
   push:
     tags:
     - "v[0-9]+.[0-9]+.[0-9]+"
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
 jobs:
   goreleaser:
     runs-on: ubuntu-latest
@@ -22,4 +27,35 @@ jobs:
           args: release --rm-dist
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          HOMEBREW_TAP_GITHUB_TOKEN: ${{ secrets.HOMEBREW_TAP_GITHUB_TOKEN }}
+          HOMEBREW_TAP_GITHUB_TOKEN: ${{ secrets.HOMEBREW_TAP_GITHUB_TOKEN }}
+
+  # ref: https://docs.github.com/ja/actions/publishing-packages/publishing-docker-images#github-packages%E3%81%B8%E3%81%AE%E3%82%A4%E3%83%A1%E3%83%BC%E3%82%B8%E3%81%AE%E5%85%AC%E9%96%8B
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@f054a8b539a109f9f41c372932f1ae047eff08c9
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@98669ae865ea3cffbcbaa878cf57c20bbf1c6c38
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@ad44023a93711e3deb337508980b4b5e9bcdc5dc
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

Dockerfile

@@ -0,0 +1,12 @@
+# syntax=docker/dockerfile:1
+FROM golang:1.18-alpine AS builder
+WORKDIR /github.com/ddddddO/gtree
+COPY go.* *.go ./
+WORKDIR /github.com/ddddddO/gtree/cmd/gtree
+COPY cmd/gtree/*.go ./
+RUN go build -o gtree .
+
+FROM alpine:latest
+WORKDIR /app
+COPY --from=builder /github.com/ddddddO/gtree/cmd/gtree/gtree ./
+ENTRYPOINT ["./gtree"]

README_CLI.md

@@ -5,12 +5,27 @@
 go version requires 1.18 or later.
 
 ```console
-go install github.com/ddddddO/gtree/cmd/gtree@latest
+$ go install github.com/ddddddO/gtree/cmd/gtree@latest
 ```
 
 or using Homebrew.
 ```console
-brew install ddddddO/tap/gtree
+$ brew install ddddddO/tap/gtree
+```
+
+or [docker image](https://github.com/ddddddO/gtree/pkgs/container/gtree).
+```console
+$ docker pull ghcr.io/ddddddo/gtree:docker
+$ docker run ghcr.io/ddddddo/gtree:docker template | docker run -i ghcr.io/ddddddo/gtree:docker output
+gtree
+├── cmd
+│   └── gtree
+│       └── main.go
+├── testdata
+│   ├── sample1.md
+│   └── sample2.md
+├── makefile
+└── tree.go
 ```
 
 **or, download binary from [here](https://github.com/ddddddO/gtree/releases).**