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Rüdiger Schulz
Rüdiger Schulz

Reputation: 3108

Getting current branch and commit hash in GitHub action

I want to build a docker image using a GitHub action, migrating from TeamCity.

In the build script, I want to tag the image with a combination of branch and commit, e.g. master.ad959de. Testing that locally, I get that information like this:

git_branch=`git symbolic-ref --short HEAD`
git_hash=`git rev-parse --short HEAD`
docker_version=${git_branch}.${git_hash}

This is the relevant part of the GitHub action:

name: CI
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v1

    - name: Create docker image
      run: ./docker-build.sh

Running that script in that GitHub action results in this error:

fatal: ref HEAD is not a symbolic ref

How can I generate a tag like that inside a GitHub action?

Upvotes: 133

Views: 181369

Answers (8)

Tiago Gouvêa
Tiago Gouvêa

Reputation: 16820

A handy way to get the currrent branch and commit sha on the workflow could be getting it and saving on a "variable".

  - name: Declare some variables
    shell: bash
    run: |
      echo "sha_short=$(git rev-parse --short "$GITHUB_SHA")" >> "$GITHUB_ENV"
      echo "branch=$(echo ${GITHUB_REF#refs/heads/})" >> "$GITHUB_ENV"
  
  - name: Another step
    run: |
      echo "Branch: ${{ env.branch }}"
      echo "Sha: ${{ env.sha_short }}"

Maybe your docker-build.sh could receive the branch and sha as parameter, os the full version as parameter.

  - name: Create docker image
     run: ./docker-build.sh "${{ env.branch }}.${{ env.sha_short }}"

OR JUST

  - name: Create docker image
     run: ./docker-build.sh "${GITHUB_REF#refs/heads/}.${GITHUB_SHA}"

On this action you can see it better.

Upvotes: 50

bodacious
bodacious

Reputation: 6705

You should be able to access the SHA for the latest Git commit with ${{ github.event.pull_request.head.sha }}, assuming this is an Action triggered by a Pull Request

Upvotes: 4

anthony sottile
anthony sottile

Reputation: 70253

from Using environment variables

github provides two variables that are useful here, you'll need to process them a bit to get the values you desire:

GITHUB_SHA: The commit SHA that triggered the workflow. For example, ffac537e6cbbf934b08745a378932722df287a53.

GITHUB_REF: The branch or tag ref that triggered the workflow. For example, refs/heads/feature-branch-1. If neither a branch or tag is available for the event type, the variable will not exist.

The short values can be extracted like this:

git_hash=$(git rev-parse --short "$GITHUB_SHA")
git_branch=${GITHUB_REF#refs/heads/}

Upvotes: 141

Fauzi Firdaus
Fauzi Firdaus

Reputation: 47

Maybe Like this

name: CI 
on: push 
jobs:   
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v1

    - name: Get Branch
      id: branch
      run: echo "git_branch=${GITHUB_REF#refs/heads/}" >> $GITHUB_BRANCH

    - name: Check Branch
      run: echo "${{ env.branch }}"

    - name: Get Hash
      id: hash
      run: echo "git_hash=$(git rev-parse --short "$GITHUB_SHA")" >> $GITHUB_HASH

    - name: Check Hash
      run: echo "${{ env.hash }}"

    - name: Create docker image
      run: ./docker-build.sh ${{ env.branch }} ${{ env.hash }}

Upvotes: 3

Abhinav Manchanda
Abhinav Manchanda

Reputation: 6641

You can get it this way in your sh file -

BRANCH_NAME=$(echo $GITHUB_REF | cut -d'/' -f 3)
GITHUB_SHA_SHORT=$(echo $GITHUB_SHA | cut -c1-7)

Upvotes: 4

Azim Saiyed
Azim Saiyed

Reputation: 582

Simplest way to get a shortened SHA using Environment variables:

- name: Build Docker Image
    run: ./docker-build.sh alpha.${GITHUB_SHA::6}

Upvotes: 12

jackotonye
jackotonye

Reputation: 3853

Using https://github.com/tj-actions/branch-names provides an output which also works for push and pull_request events


...
    steps:
      - uses: actions/checkout@v2
      - name: Get branch names
        uses: tj-actions/[email protected]
        id: branch-names
      
      - name: Current branch name
        if: github.event_name == 'pull_request'
        run: |
          echo "${{ steps.branch-name.outputs.current_branch }}"
        # Outputs: "feature/test" current PR branch.
      
      - name: Current branch name
        if: github.event_name == 'push'
        run: |
          echo "${{ steps.branch-name.outputs.current_branch }}"
        # Outputs: "main" the default branch that triggered the push event.
      
      - name: Get Ref brach name
        run: |
          echo "${{ steps.branch-name.outputs.ref_branch }}"
        #  Outputs: "main" for non PR branches | "1/merge" for a PR branch

      - name: Get Head Ref branch name
        if: github.event_name == 'pull_request'
        run: |
          echo "${{ steps.branch-name.outputs.head_ref_branch }}"
        # Outputs: "feature/test" current PR branch.

      - name: Get Base Ref branch name
        if: github.event_name == 'pull_request'
        run: |
          echo "${{ steps.branch-name.outputs.base_ref_branch }}"
        # Outputs: "main" for main <- PR branch.

Upvotes: 1

ifoukarakis
ifoukarakis

Reputation: 1932

Another approach is to use github context.

- name: Create docker image
  run: ./docker-build.sh ${{ github.head_ref }}.${{ github.sha }}

The benefit of this approach is that you don't have to add a step to set the values. Note that it uses the full version of the sha (not the short version).

Upvotes: 143

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