Added helper to run workflows on forks (#3197)

* Added workflow helper for the forked repositories.

* Use secret.ARMBIAN_SELF_DISPATCH_TOKEN, Added `event_details`

* Use secret.ARMBIAN_SELF_DISPATCH_TOKEN, Added `event_details`

* Updated .github/workflows/README.md with `armbian` event

* Fix newline in the end of yaml.

* Remove `Debug details` step

* Added comment for JSON processing

.github/workflows/README.md

@@ -25,3 +25,31 @@ use gpg1 otherwise signing fails
         sudo ./svc.sh install # install
         sudo ./svc.sh start   # start
         sudo ./svc.sh status  # check
+
+# Use workflows in forked repositories
+
+`forked-helper.yml` workflow helper can help to run custom workflows on the forked repositories.
+
+1. Set `ARMBIAN_SELF_DISPATCH_TOKEN` secret on your repository with `security_events` permissions.
+2. Helper will dispatch `repository_dispatch` event `armbian` on `push`, `release`, `deployment`, 
+   `pull_request` and `workflow_dispatch` events. All needed event details you can find in `client_payload` 
+   property of the event.
+4. Create empty default branch in forked repository
+5. Create workflow with `repository_dispatch` in default branch.
+6. Run any need actions in this workflow.
+
+Workflow example:
+```yaml
+name: Test Armbian dispatch
+
+on:
+  repository_dispatch:
+    types: ["armbian"]
+
+jobs:
+  show-dispatch:
+    name: Show dispatch event details
+    runs-on: ubuntu-latest
+    steps:
+      - uses: hmarr/debug-action@v2
+```

.github/workflows/forked-helper.yml

@@ -0,0 +1,42 @@
+name: Forked helper
+
+on:
+  push:
+  release:
+  deployment:
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  fork-repository-dispatch:
+    name: 📢 Run repository dispatch to default fork branch
+    if: ${{ github.repository_owner != 'armbian' }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Assign secret
+        id: get_dispatch_secret
+        run: echo '::set-output name=dispatch_secret::${{ secrets.ARMBIAN_SELF_DISPATCH_TOKEN }}'
+      - name: Get event details
+        id: get_event_details
+        # Process JSON according https://github.community/t5/GitHub-Actions/set-output-Truncates-Multiline-Strings/td-p/37870
+        run: |
+          JSON=$(cat ${{ github.event_path }})
+          JSON="${JSON//'%'/'%25'}"
+          JSON="${JSON//$'\n'/'%0A'}"
+          JSON="${JSON//$'\r'/'%0D'}"
+          echo "::set-output name=event_details::${JSON}"
+      - name: Dispatch event on forked repostitory
+        if: steps.get_dispatch_secret.outputs.dispatch_secret
+        uses: peter-evans/repository-dispatch@v1
+        with:
+          token: ${{ steps.get_dispatch_secret.outputs.dispatch_secret }}
+          repository: ${{ github.repository }}
+          event-type: armbian
+          client-payload: >
+            {
+              "event": "${{ github.event_name }}",
+              "ref": "${{ github.ref }}",
+              "base_ref": "${{ github.base_ref }}",
+              "sha": "${{ github.sha }}",
+              "event_details": ${{ steps.get_event_details.outputs.event_details }}
+            }