CLDC-4236: use pr comment trigger

.github/workflows/review_app_prompt.yml

@@ -0,0 +1,24 @@
+name: Review app deploy prompt
+
+on:
+  pull_request:
+    types: [opened]
+
+jobs:
+  prompt:
+    name: Add review app deploy instructions
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+
+    steps:
+      - name: Comment with deploy instructions
+        uses: actions/github-script@v7
+        with:
+          script: |
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body: 'To deploy a review app for this PR, comment `/deploy-review`.',
+            });

.github/workflows/review_pipeline.yml

@@ -1,46 +1,64 @@
 name: Review app pipeline
 
-concurrency:
-  group: review-${{ inputs.pull_request_id }}
-
 on:
-  workflow_dispatch:
-    inputs:
-      pull_request_id:
-        required: true
-        type: string
-        description: "The pull request ID to deploy a review app for."
+  issue_comment:
+    types: [created]
 
 defaults:
   run:
     shell: bash
 
 jobs:
+  setup:
+    name: Resolve PR details
+    if: github.event.issue.pull_request && startsWith(github.event.comment.body, '/deploy-review')
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: read
+    outputs:
+      pr_number: ${{ steps.resolve.outputs.pr_number }}
+      ref: ${{ steps.resolve.outputs.ref }}
+    steps:
+      - name: Resolve PR number and ref
+        id: resolve
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const prNumber = context.issue.number;
+            const { data: pr } = await github.rest.pulls.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: prNumber,
+            });
+            core.setOutput('pr_number', prNumber.toString());
+            core.setOutput('ref', pr.head.ref);
+
   infra:
     name: Deploy review app infrastructure
+    needs: [setup]
     uses: communitiesuk/submit-social-housing-lettings-and-sales-data-infrastructure/.github/workflows/create_review_app_infra.yml@main
     with:
-      key: ${{ inputs.pull_request_id }}
+      key: ${{ needs.setup.outputs.pr_number }}
       app_repo_role: arn:aws:iam::815624722760:role/core-application-repo
     permissions:
       id-token: write
 
   code:
     name: Deploy review app code
-    needs: [infra]
+    needs: [setup, infra]
     uses: ./.github/workflows/aws_deploy.yml
     with:
       aws_account_id: 837698168072
       aws_role_prefix: core-dev
-      aws_task_prefix: core-review-${{ inputs.pull_request_id }}
-      concurrency_tag: ${{ inputs.pull_request_id }}
+      aws_task_prefix: core-review-${{ needs.setup.outputs.pr_number }}
+      concurrency_tag: ${{ needs.setup.outputs.pr_number }}
       environment: review
     permissions:
       id-token: write
 
   comment:
     name: Add link to PR
-    needs: [code]
+    needs: [setup, code]
     runs-on: ubuntu-latest
     permissions:
       pull-requests: write
@@ -50,19 +68,19 @@ jobs:
         uses: actions/github-script@v7
         with:
           script: |
-            const pullRequestId = ${{ inputs.pull_request_id }};
-            const body = `Created review app at https://review.submit-social-housing-data.communities.gov.uk/${pullRequestId}. Note that the review app will be automatically deprovisioned after 30 days and will need the review app pipeline running again.`;
+            const prNumber = ${{ needs.setup.outputs.pr_number }};
+            const body = `Created review app at https://review.submit-social-housing-data.communities.gov.uk/${prNumber}. Note that the review app will be automatically deprovisioned after 30 days and will need the review app pipeline running again.`;
             const { data: comments } = await github.rest.issues.listComments({
               owner: context.repo.owner,
               repo: context.repo.repo,
-              issue_number: pullRequestId,
+              issue_number: prNumber,
             });
             const duplicate = comments.find(c => c.body.startsWith('Created review app at'));
             if (!duplicate) {
               await github.rest.issues.createComment({
                 owner: context.repo.owner,
                 repo: context.repo.repo,
-                issue_number: pullRequestId,
+                issue_number: prNumber,
                 body: body,
               });
             }