Github Action trigger on another repo update (push, pull_request)

Question

I'm having some trouble setting up a proper build chain for me and some friends. So, I forked two repos, the official ghidra and ghidra-ci. ghidra-ci is an repo which builds your fork of ghidra, when you cherry-pick some pr's so, you can add some things which aren't added to the official ghidra repo yet.

So, ghidra-ci should build the ghidra repo when the ghidra repo is updated. So far I managed to get it to build when ghidra-ci itself is updatet. I used

name: Ghidra Build
on: [push, pull_request]

(After this are only the build jobs)

So, I know this is wrong. I deleted the on: line, but I it wants a on: line, I just pasted on: [workflow_dispatch] in. I don't know if this is gonna work.

I have a workflow called "Check for new commits"

name: Check for new commits
on:
  schedule:
    - cron: '30 12 * * *'
  workflow_dispatch:
    inputs: {}

jobs:
  # Ensure all steps use a common revision
  check:
    name: Check for new commits since last release
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          repository: Lockna/Ghidra
      - name: Check for new commits
        id: check
        run: |
          LAST_REL_NAME=$(curl --silent "https://api.github.com/repos/${{github.repository}}/releases/latest" | jq .name)
          LAST_REL_COMMITID=$(echo $LAST_REL_NAME | grep -oP "$\K\w+(?=$)")
          COMMIT_HASH_SHORT=$(git rev-parse --short HEAD)
          COMMIT_HASH_LONG=$(git rev-parse HEAD)
          echo "Latest commit is $COMMIT_HASH_LONG"
          if [[ "$LAST_REL_NAME" == *"$COMMIT_HASH_SHORT"* ]]; then
            echo "No commits since last release $LAST_REL_NAME"
          else
            echo "Found new commits since $LAST_REL_NAME. Triggering ci."
            echo ::set-output name=trigger::true
            echo ::set-output name=rev::$COMMIT_HASH_LONG
            echo ::set-output name=lastrev::$LAST_REL_COMMITID
          fi
      - name: Trigger build
        if: steps.check.outputs.trigger
        uses: benc-uk/workflow-dispatch@v1.1
        with:
          workflow: "Ghidra Build"
          repo: Lockna/ghidra-ci
          token: ${{secrets.PAT_TOKEN}}
          inputs: '{ "rev": "${{steps.check.outputs.rev}}", "prevRev": "${{steps.check.outputs.lastrev}}" }'

so, this workflow should check (I would prefer that it triggers when I'm updating the ghidra itself, but I have found out that this doesn't work out as I would like to) if there are some changes and if there are some it should trigger the "Ghidra Build" workflow. For testing I run this build manually

Run benc-uk/workflow-dispatch@v1.1
  with:
    workflow: Ghidra Build
    repo: Lockna/ghidra-ci
    token: ***
    inputs: { "rev": "c1a1674214007bf467dd90f6d80fda453d25b16c", "prevRev": "133d6c2" }
Workflow id is: 3932827
Error: Unexpected inputs provided

That's the error message I get. I don't know what else I could try to get this work. If someone has a solution where it really builds when ghidra repo is updated, I would like to hear that.

user_3266847 · Answer

You could have ghidra-ci listen to the repository_dispatch event:

name: Listener for ghidra

on:
  repository_dispatch:
  workflow_dispatch:

jobs:
  dump:
    runs-on: ubuntu-20.04
    steps:
      - name: Dump event payload
        run: |
          jq . "$GITHUB_EVENT_PATH"

workflow_dispatch is there so you can manually trigger the workflow for test purposes. The run step just dumps the event payload, and you can replace that with whatever build steps you want; you can further filter which events should trigger by filtering by event type, such as

on:
  repository_dispatch:
    types:
      - mytrigger

In ghidra, you can generate that event by sending a POST request to /repos/Lockna/ghidra-ci/dispatches, for example using the GitHub CLI:

name: Notify ghidra-ci

on:
  push:
  workflow_dispatch:

jobs:
  notify:
    runs-on: ubuntu-20.04
    steps:
      - name: Create repository dispatch event
        env:
          GITHUB_TOKEN: ${{ secrets.PAT_TOKEN }}
        run: |
          gh api repos/Lockna/ghidra-ci/dispatches \
              --raw-field event_type=mytrigger

Again, the workflow_dispatch trigger is there to allow manual triggering.

For authentication, you must use a personal access token with at least public_repo scope; $GITHUB_TOKEN alone doesn't work.

The value set for event_type shows up as action in the event payload.

Github Action trigger on another repo update (push, pull_request)

1 Answers