Trigger your CircleCI pipelines from any event on Github with Github Actions.

1. Create a Github Action's workflow for the desired CircleCI pipeline.

   Do this by adding a workflow YAML file (we'll use main.yml) to ./.github/workflows.

   A release trigger is shown in this example. Try any of the Github events for triggering workflows: https://docs.github.com/en/actions/learn-github-actions/events-that-trigger-workflows

   Select a custom name and id for the step for additional contextual metadata in your CircleCI pipeline

on:
  release:
    types: [published]
jobs:
  trigger-circleci:
    runs-on: ubuntu-latest
    steps:
      - name: <customize name>
        id: <customize id>
        uses: circleci/trigger_circleci_pipeline@v1.0
        env:
          CCI_TOKEN: ${{ secrets.CCI_TOKEN }}

2. Create an encrypted secret named CCI_TOKEN containing the Personal API Token that will be used to trigger the pipelines. This is suggested to be a machine user.

3. Add the Pipeline Parameter definitions to your CircleCI config. This data will be entered by the GitHub Action when triggered.

   Add the following to the top of your .circleci/config.yml file. Ensure you are specifying version 2.1

   version: 2.1
   parameters:
     GHA_Actor:
       type: string
       default: ""
     GHA_Action:
       type: string
       default: ""
     GHA_Event:
       type: string
       default: ""
     GHA_Meta:
       type: string
       default: ""

4. Use the Pipeline Parameter data to run workflows conditionally.

   See: Examples

Optional input parameters that allow you to specify additional metadata.

required: false

description: An optional additional metadata parameter. Will be available on the CircleCI pipeline as GHA_Meta.

jobs:
  trigger-circleci:
    runs-on: ubuntu-latest
    steps:
      - name: <customize name>
        id: <customize id>
        uses: circleci/trigger_circleci_pipeline@v1.0
        with:
          GHA_Meta: "<custom data>"
        env:
          CCI_TOKEN: ${{ secrets.CCI_TOKEN }}

By default, when a repository is connected to CircleCI, if the workflows within that project's configuration does not specify any conditionals or filters that would otherwise prevent execution, the workflow will execute on every push event by default.

This may mean it is possible to accidentally run a job twice, once on the push event from CircleCI, as well as other events triggered by the GitHub Action.

If you are relying on GitHub Actions to provide all of your API triggers, ensure that each of your CircleCI configuration's workflows contains a conditional limiting it's execution to only the GitHub Action trigger.

Example

workflows:
  # This workflow is set to be conditionally triggered,
  # only via the GitHub Action.
  # With no other unfiltered workflows, normal push events will be ignored.
  when: << pipeline.parameters.GHA_Action >>
  test:
    jobs:
      - test