Check if a github tag exists in a repo within a github action

May 4, 2023

I am trying to check if a specific tag exists in a repository. Here is a simplified version of what I have tried so far.

Attempt 1:

name: Check for Tag

on: push

jobs:
  check-tag:
    runs-on: ubuntu-latest

    steps:
      - name: Check for Tag
        run: |
          TAG="0.1"
          if git show-ref --tags --verify --quiet "refs/tags/${TAG}"; then
            echo "Tag ${TAG} exists"
          else
            echo "Tag ${TAG} does not exist"
          fi

Output: Tag 0.1 does not exist

However if i execute the following command on CLI, the tag exists

git show-ref --tags --verify returns an exit code of 0 if the tag has been found.

Attempt 2:

name: Check for Tag

on: push

jobs:
  check-tag:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v2
        
      - name: Check for Tag
        run: |
          TAG="0.2"
          git show-ref --tags --verify --quiet "refs/tags/${TAG}" 
          exit_code=$?
          echo ${exit_code}
          if [[ $exit_code -eq 0 ]]; then
            echo "Tag ${TAG} exists"
          else
            echo "Tag ${TAG} does not exist"
          fi

The workflow fails because 0.2 tag does not exist and returns 1 as exit code

>Solution :

You need the complete git history to query that.

Use fetch-depth: 0 with actions/checkout.

Here’s your updated workflow:

name: Check for Tag

on: push

jobs:
  check-tag:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v3
        with:
          fetch-depth: 0
        
      - name: Check for Tag
        run: |
          TAG="0.2"
          if git show-ref --tags --verify --quiet "refs/tags/${TAG}"; then
            echo "Tag ${TAG} exists"
          else
            echo "Tag ${TAG} does not exist"
          fi

See https://github.com/actions/checkout for more details.