Error: buildx failed with: error: invalid tag "docker.pkg.github.com/myself/cmms:": invalid reference format

Question

I have used github actions for CI.

I got an error in build and push: Error: buildx failed with: error: invalid tag "docker.pkg.github.com/myself/cmms:": invalid reference format

main.yml

   name: ci
on:
  workflow_dispatch: 
  push:
    tags:
      - "v*.*"
env:
  IMAGE_NAME: CMMS 
jobs:
  get-tags:
    runs-on: ubuntu-20.04
    env:
      TZ: Asia/Shanghai
    outputs:
      tags: ${{ steps.set-output-id.outputs.tags }}
    steps:
      - uses: actions/checkout@v2
      - name: set-output
        id: set-output-id
        run: |
          VERSION=edge
          if [[ $GITHUB_REF == refs/tags/* ]]; then
            VERSION=${GITHUB_REF#refs/tags/v}
          fi
          echo ::set-output name=tags::${VERSION}          
  push-ghcr:
    runs-on: ubuntu-20.04
    env:
      TZ: Asia/Shanghai
      REGISTRY: docker.pkg.github.com
    steps:
      - uses: actions/checkout@v2
      - name: Login
        uses: docker/login-action@v1
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.repository_owner }}
          password: ${{ secrets.PACKAGES_TOKEN }}
      - name: Build && Push
        uses: docker/build-push-action@v2
        with:
          context: .
          file: ./Dockerfile
          push: true
          tags: |
            ${{ env.REGISTRY }}/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}:${{ needs.get-tags.outputs.tags }}
            ${{ env.REGISTRY }}/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}:latest          

dockerfile:

FROM python:3.7
ENV PYTHONUNBUFFERED 1
RUN apt-get update
RUN mkdir /code
WORKDIR /code
ADD requirements.txt /code/
RUN pip install -r requirements.txt
ADD . /code/
EXPOSE 8000
CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]

How could I fix this error? The yaml file was copied from some technical blog, which should work well.

Answer 1

It's complaining that the tag is missing, and your image name (reference) has a trailing colon so it's expecting a tag. I'm not familiar with the needs syntax, normally I'd pass an output with the steps syntax:

tags: |
            ${{ env.REGISTRY }}/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}:${{steps.get-tags.outputs.tags }}
            ${{ env.REGISTRY }}/${{ github.repository_owner }}/${{ env.IMAGE_NAME }}:latest