Send a custom workflow status embed to Discord

This commit introduces the same custom status embed as is already being
used for Sir Lancebot. The default embeds GitHub sends are disabled, as
they were causing slight issues with rate limits from time to time.

It works like this:

- The Lint & Test workflow stores an artifact with PR information, if we
  are linting/testing a PR.

- Whenever we reach the end of a workflow run sequence, a status embed
  is send with the conclusion status.

Signed-off-by: Sebastiaan Zeeff <[email protected]>

2 files changed, 100 insertions, 0 deletions

diff --git a/.github/workflows/lint-test.yml b/.github/workflows/lint-test.yml
index 5444fc3de..a38f031fa 100644
--- a/.github/workflows/lint-test.yml
+++ b/.github/workflows/lint-test.yml
@@ -113,3 +113,25 @@ jobs:
         env:
             GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: coveralls
+
+      # Prepare the Pull Request Payload artifact. If this fails, we
+      # we fail silently using the `continue-on-error` option. It's
+      # nice if this succeeds, but if it fails for any reason, it
+      # does not mean that our lint-test checks failed.
+      - name: Prepare Pull Request Payload artifact
+        id: prepare-artifact
+        if: always() && github.event_name == 'pull_request'
+        continue-on-error: true
+        run: cat $GITHUB_EVENT_PATH | jq '.pull_request' > pull_request_payload.json
+
+      # This only makes sense if the previous step succeeded. To
+      # get the original outcome of the previous step before the
+      # `continue-on-error` conclusion is applied, we use the
+      # `.outcome` value. This step also fails silently.
+      - name: Upload a Build Artifact
+        if: steps.prepare-artifact.outcome == 'success'
+        continue-on-error: true
+        uses: actions/upload-artifact@v2
+        with:
+          name: pull-request-payload
+          path: pull_request_payload.json
diff --git a/.github/workflows/status_embed.yaml b/.github/workflows/status_embed.yaml
new file mode 100644
index 000000000..b6a71b887
--- /dev/null
+++ b/.github/workflows/status_embed.yaml
@@ -0,0 +1,78 @@
+name: Status Embed
+
+on:
+  workflow_run:
+    workflows:
+      - Lint & Test
+      - Build
+      - Deploy
+    types:
+      - completed
+
+jobs:
+  status_embed:
+    # We need to send a status embed whenever the workflow
+    # sequence we're running terminates. There are a number
+    # of situations in which that happens:
+    #
+    # 1. We reach the end of the Deploy workflow, without
+    #    it being skipped.
+    #
+    # 2. A `pull_request` triggered a Lint & Test workflow,
+    #    as the sequence always terminates with one run.
+    #
+    # 3. If any workflow ends in failure or was cancelled.
+    if: >-
+      (github.event.workflow_run.name == 'Deploy' && github.event.workflow_run.conclusion != 'skipped') ||
+      github.event.workflow_run.event == 'pull_request' ||
+      github.event.workflow_run.conclusion == 'failure' ||
+      github.event.workflow_run.conclusion == 'cancelled'
+    name:  Send Status Embed to Discord
+    runs-on: ubuntu-latest
+
+    steps:
+      # A workflow_run event does not contain all the information
+      # we need for a PR embed. That's why we upload an artifact
+      # with that information in the Lint workflow.
+      - name: Get Pull Request Information
+        id: pr_info
+        if: github.event.workflow_run.event == 'pull_request'
+        run: |
+          curl -s -H "Authorization: token $GITHUB_TOKEN" ${{ github.event.workflow_run.artifacts_url }} > artifacts.json
+          DOWNLOAD_URL=$(cat artifacts.json | jq -r '.artifacts[] | select(.name == "pull-request-payload") | .archive_download_url')
+          [ -z "$DOWNLOAD_URL" ] && exit 1
+          wget --quiet --header="Authorization: token $GITHUB_TOKEN" -O pull_request_payload.zip $DOWNLOAD_URL || exit 2
+          unzip -p pull_request_payload.zip > pull_request_payload.json
+          [ -s pull_request_payload.json ] || exit 3
+          echo "::set-output name=pr_author_login::$(jq -r '.user.login // empty' pull_request_payload.json)"
+          echo "::set-output name=pr_number::$(jq -r '.number // empty' pull_request_payload.json)"
+          echo "::set-output name=pr_title::$(jq -r '.title // empty' pull_request_payload.json)"
+          echo "::set-output name=pr_source::$(jq -r '.head.label // empty' pull_request_payload.json)"
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      # Send an informational status embed to Discord instead of the
+      # standard embeds that Discord sends. This embed will contain
+      # more information and we can fine tune when we actually want
+      # to send an embed.
+      - name: GitHub Actions Status Embed for Discord
+        uses: SebastiaanZ/[email protected]
+        with:
+          # Our GitHub Actions webhook
+          webhook_id: '784184528997842985'
+          webhook_token: ${{ secrets.GHA_WEBHOOK_TOKEN }}
+
+          # Workflow information
+          workflow_name: ${{ github.event.workflow_run.name }}
+          run_id: ${{ github.event.workflow_run.id }}
+          run_number: ${{ github.event.workflow_run.run_number }}
+          status: ${{ github.event.workflow_run.conclusion }}
+          actor: ${{ github.actor }}
+          repository:  ${{ github.repository }}
+          ref: ${{ github.ref }}
+          sha: ${{ github.event.workflow_run.head_sha }}
+
+          pr_author_login: ${{ steps.pr_info.outputs.pr_author_login }}
+          pr_number: ${{ steps.pr_info.outputs.pr_number }}
+          pr_title: ${{ steps.pr_info.outputs.pr_title }}
+          pr_source: ${{ steps.pr_info.outputs.pr_source }}