Commit Hash

A GitHub Action for using the long and short hash of a commit — with an optional prefix.

prompt/actions-commit-hash@v3

📦 Automatic Release Packaging is used by this action, please reference by tag or commit hash in your Workflows.

Inputs

All inputs are optional.

ID	Description	Default	Examples
commit	Full, 40-character SHA-1 hash of the commit	${{github.sha}}	734713bc047d87bf7eac9674765ae793478c50d3
prefix	Optional string prepended to short and long		commit sha-

Outputs

ID	Description	Examples
short	Short, 7-character hash of the commit with optional prefix	734713b sha-734713b
long	Full, 40-character SHA-1 hash of the commit with optional prefix	734713bc047d87bf7eac9674765ae793478c50d3 sha-734713bc047d87bf7eac9674765ae793478c50d3
hash	Original, 40-character SHA-1 hash of the commit without prefix	734713bc047d87bf7eac9674765ae793478c50d3

Examples

Build image with commit tag

docker/build-push-action builds Docker images with tags, here we tag the image we're building with the short commit hash.

jobs:
  tag-image:
    runs-on: ubuntu-latest
    steps:
    steps:
      - id: commit
        uses: prompt/actions-commit-hash@v3
      - uses: docker/setup-buildx-action@v3
      - name: Build image for commit
        uses: docker/build-push-action@v5
        with:
          push: true
          tags: ${{ steps.commit.outputs.short }}

Prefix commit hash for workflow_run event

workflow_run events are handled by Workflows within the context of the main branch, therefore the github.sha context value does not represent the commit that triggered the Workflow and we must use the head_sha value on the event instead.

on:
  workflow_run:
    workflows:
      - Build
    types:
      - completed

jobs:
  tag-image:
    runs-on: ubuntu-latest
    steps:
    steps:
      - id: commit
        uses: prompt/actions-commit-hash@v3
        with:
          commit: "${{ github.event.workflow_run.head_sha }}"
          prefix: "sha-"
      - uses: docker/setup-buildx-action@v3
      - name: Build image for commit
        uses: docker/build-push-action@v5
        with:
          push: true
          tags: ${{ steps.commit.outputs.short }}

Automatic Release Packaging

Packaging (creation of dist) happens automatically when a new tag is created. Any reference to this Action in a Workflow must use a tag (mutable) or the commit hash of a tag (immutable).

✅ uses: prompt/actions-commit-hash@v3
✅ uses: prompt/actions-commit-hash@v3.0.0
✅ uses: prompt/actions-commit-hash@01d19a83c242e1851c9aa6cf9625092ecd095d09
❌ uses: prompt/actions-commit-hash@main

The blog post Package GitHub Actions automatically with GitHub Actions describes how this is achieved.