PCSM. Change CI workflow to dynamically select branch in QA repo (#164)

Author: sandraromanchenko

.github/workflows/ci.yml

@@ -37,11 +37,37 @@ jobs:
     env:
       PCSM_BRANCH: ${{ github.event_name == 'pull_request' && github.head_ref || github.event.inputs.pcsm_branch || 'main' }}
     steps:
+      - name: Determine test branch
+        id: test_branch
+        run: |
+          if [ -n "${{ github.event.inputs.tests_ver }}" ]; then
+            echo "branch=${{ github.event.inputs.tests_ver }}" >> $GITHUB_OUTPUT
+          elif [ -n "${{ github.event.pull_request.title }}" ]; then
+            PR_TITLE="${{ github.event.pull_request.title }}"
+            echo "PR title: $PR_TITLE"
+            BRANCH_TO_CHECK=$(echo "$PR_TITLE" | grep -oE 'PCSM-[0-9]+' | head -1)
+            if [ -n "$BRANCH_TO_CHECK" ]; then
+              echo "Extracted branch pattern: $BRANCH_TO_CHECK"
+              if curl -sf "https://api.github.com/repos/Percona-QA/psmdb-testing/branches/$BRANCH_TO_CHECK" > /dev/null; then
+                echo "Branch $BRANCH_TO_CHECK found, using it"
+                echo "branch=$BRANCH_TO_CHECK" >> $GITHUB_OUTPUT
+              else
+                echo "Branch $BRANCH_TO_CHECK not found, falling back to main"
+                echo "branch=main" >> $GITHUB_OUTPUT
+              fi
+            else
+              echo "No PCSM-XXXXX pattern found in PR title, using main"
+              echo "branch=main" >> $GITHUB_OUTPUT
+            fi
+          else
+            echo "branch=main" >> $GITHUB_OUTPUT
+          fi
+
       - name: Checkout testing repo
         uses: actions/checkout@v4
         with:
           repository: Percona-QA/psmdb-testing
-          ref: ${{ github.event.inputs.tests_ver || 'main'}}
+          ref: ${{ steps.test_branch.outputs.branch }}
           path: psmdb-testing
 
       - name: Setup environment with PSMDB ${{ matrix.psmdb }} and PCSM PR/branch ${{ github.head_ref || github.event.inputs.pcsm_branch || env.PCSM_BRANCH }}