.github/workflows/deploy.yml

deploy.yml

name: Deploy

on:
  push:
    branches: [main]

jobs:
  deploy:
    env:
      GIT_TERMINAL_PROMPT: 1

    runs-on: ubuntu-latest
    steps:
      - name: github private modules access
        run: git config --global url."https://${{ secrets.PAT }}:x-oauth-basic@github.com/".insteadOf "https://github.com/"

      - name: Check out code into the Go module directory
        uses: actions/checkout@v3

      - name: Set up cache
        uses: actions/cache@v3
        with:
          path: /tmp/.buildx-cache
          key: ${{ runner.os }}-buildx-${{ github.sha }}
          restore-keys: |
            ${{ runner.os }}-buildx-

      - uses: docker/setup-buildx-action@v2

      - name: Log in to the Container registry
        uses: docker/login-action@v2
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
          password: ${{ secrets.GITHUB_TOKEN }}

      # If this fails due to 403 Forbidden, you'll check https://github.com/docker/build-push-action/issues/463#issuecomment-924995909
      - uses: docker/build-push-action@v3
        with:
          context: .
          push: true
          tags: ghcr.io/${{ github.repository_owner }}/${{ github.event.repository.name }}:latest

GithubのOrganization→Settings→Secrets and variables→ActionsにPATというSecretsを登録しておいて，Dockerfileをレポジトリのルートに含むレポジトリで，.github/workflows以下に上記をdeploy.ymlとしておくと，mainブランチにpushされるごとにイメージを作ってくれる

最初のdeploy(push image)が失敗する時，レポジトリのSettings->Actions->General->Workflow permissionsでRead and write permissions にチェックが入っているか確認