I've got a Github workflow for a CI build that looks like this:

- name: Checkout meta-repo
  uses: actions/checkout@v4
  with:
    ssh-key: ${{ secrets.CI_BUILD_PRIVATE_SSH_KEY }}
    repository: meta-repo
    ref: ${{ github.event.client_payload.ref || 'dev' }}
    path: meta-repo

The github.event.client_payload.ref comes from enabling repository_dispatch - if that's not defined then we default to the dev branch. But this means when we build the main branch for this repo we use the dev branch from meta-repo which is incorrect. What I want to do is say:

1. If github.event.client_payload.ref is defined then checkout that.
2. If we're in main then checkout main.
3. Otherwise checkout dev.

I can't see a way of doing this. There's an if command but that seems to be for conditionally running entire steps. Is that the only way to achieve this?

I've got a Github workflow for a CI build that looks like this:

- name: Checkout meta-repo
  uses: actions/checkout@v4
  with:
    ssh-key: ${{ secrets.CI_BUILD_PRIVATE_SSH_KEY }}
    repository: meta-repo
    ref: ${{ github.event.client_payload.ref || 'dev' }}
    path: meta-repo

The github.event.client_payload.ref comes from enabling repository_dispatch - if that's not defined then we default to the dev branch. But this means when we build the main branch for this repo we use the dev branch from meta-repo which is incorrect. What I want to do is say:

1. If github.event.client_payload.ref is defined then checkout that.
2. If we're in main then checkout main.
3. Otherwise checkout dev.

I can't see a way of doing this. There's an if command but that seems to be for conditionally running entire steps. Is that the only way to achieve this?

• github-actions

2 Answers 2

According to GitHub Actions Operators:

GitHub offers ternary operator like behaviour that you can use in expressions. By using a ternary operator in this way, you can dynamically set the value of an environment variable based on a condition, without having to write separate if-else blocks for each possible option.

Example:

env:
  MY_ENV_VAR: ${{ github.ref == 'refs/heads/main' && 'value_for_main_branch' || 'value_for_other_branches' }}

So, you can use the ternary expression

${{ expression && true-case || false-case }}

and chain it according to your use case.

Here's an example:

- name: Checkout
  uses: actions/checkout@v4
  with:
    ref: ${{ github.event.client_payload.ref && github.event.client_payload.ref || (github.ref_name == 'main' && 'main' || 'dev') }}

A long expression may span onto multiple lines:

- name: Checkout
  uses: actions/checkout@v4
  with:
    ref: >-
      ${{ github.event.client_payload.ref && github.event.client_payload.ref
       || (github.ref_name == 'main' && 'main' || 'dev') }}

For YAML's folding and stripping with >-, See https://yaml-multiline.info/ for more details and interactive examples.

you can add a condition before code checkout 

jobs:
  runs-on: [xx]
  steps:
     - name: Checkout - main ref or client payload ref
       if: github.ref_name == 'main'
       uses: actions/checkout@v4
       with:
         ssh-key: xx
         repository: meta-repo
         ref: ${{ github.event.client_payload.ref || 'main' }}
         path: xx
     - name: Checkout - dev ref or client payload ref
       if: github.ref_name != 'main'
       uses: actions/checkout@v4
       with:
         ssh-key: xx
         repository: meta-repo
         ref: ${{ github.event.client_payload.ref || 'dev' }}
         path: xx