replace backport label with a more flexible backport command (#17497)

* replace backport label with a more flexible backport command

* fix backport bot command

.github/workflows/auto-backport.yml

-# Creates a pull request with the latest release branch as a target with a cherry-picked commit if an associated pull request has `backport` label
-name: AutoBackport
-
-on:
-  push:
-    branches:
-      - master
-
-jobs:
-  pr_info:
-    name: Check if the commit should be backported
-    runs-on: ubuntu-latest
-    outputs:
-      title: ${{ fromJson(steps.collect_pr_info.outputs.result).title }}
-      number: ${{ fromJson(steps.collect_pr_info.outputs.result).pullRequestNumber }}
-      author: ${{ fromJson(steps.collect_pr_info.outputs.result).author }}
-      should_backport: ${{ fromJson(steps.collect_pr_info.outputs.result).hasBackportLabel }}
-    steps:
-      - uses: actions/github-script@v4
-        id: collect_pr_info
-        with:
-          script: |
-            const commitMessage = context.payload.commits[0].message;
-            const pullRequestNumbers = Array.from(commitMessage.matchAll(/\(#(.*?)\)/g))
-
-            if (pullRequestNumbers.length === 0) {
-              return;
-            }
-
-            if (pullRequestNumbers > 1) {
-              throw "Multiple PRs are associated with this commit";
-            }
-
-            const pullRequestNumber = pullRequestNumbers[0][1];
-
-            const { data } = await github.pulls.get({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              pull_number: pullRequestNumber
-            });
-
-            const hasBackportLabel = data.labels.some((label) => label.name === 'backport');
-            const { title, user } = data
-
-            console.log(`PR #${pullRequestNumber}: "${title}" hasBackportLabel=${hasBackportLabel}`)
-
-            return {
-              author: user.login,
-              pullRequestNumber,
-              title: data.title,
-              hasBackportLabel
-            }
-
-  get_latest_release_branch:
-    name: Get latest release branch
-    runs-on: ubuntu-latest
-    outputs:
-      branch_name: ${{ steps.get_branch_name.outputs.result }}
-    steps:
-      - uses: actions/github-script@v4
-        id: get_branch_name
-        with:
-          result-encoding: string
-          script: |
-            const releaseBranches = await github.git.listMatchingRefs({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              ref: "heads/release-x.",
-            });
-
-            const getVersionFromBranch = branch => {
-              const match = branch.match(/release-x\.(.*?)\.x/);
-              return match && parseInt(match[1])
-            };
-            const latestReleaseBranch = releaseBranches.data
-              .filter(branch => getVersionFromBranch(branch.ref) !== null)
-              .reduce((prev, current) => getVersionFromBranch(prev.ref) > getVersionFromBranch(current.ref) ? prev : current);
-            const latestReleaseBranchName = latestReleaseBranch.ref.replace(/^refs\/heads\//, "");
-
-            console.log(`Latest release branch: ${latestReleaseBranchName}`)
-
-            return latestReleaseBranchName;
-
-  create_backport_pull_request:
-    runs-on: ubuntu-latest
-    name: Create a backport PR with the commit
-    needs: [pr_info, get_latest_release_branch]
-    if: ${{ needs.pr_info.outputs.should_backport == 'true' }}
-    env:
-      RELEASE_BRANCH: ${{ needs.get_latest_release_branch.outputs.branch_name }}
-      ORIGINAL_PR_TITLE: ${{ needs.pr_info.outputs.title }}
-      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-    steps:
-      - uses: actions/checkout@v2
-        name: Checkout
-        with:
-          fetch-depth: 0
-      - run: |
-          git config --global user.email "metabase-github-automation@metabase.com"
-          git config --global user.name "$GITHUB_ACTOR"
-
-          PR_BRANCH="backport-$GITHUB_SHA"
-
-          git fetch --all
-          git checkout -b "${PR_BRANCH}" origin/"${RELEASE_BRANCH}"
-          git cherry-pick "${GITHUB_SHA}"
-          git push -u origin "${PR_BRANCH}"
-
-          hub pull-request -b "${RELEASE_BRANCH}" -h "${PR_BRANCH}" -l "auto-created-backport" -a "${GITHUB_ACTOR}" -m "backported \"${ORIGINAL_PR_TITLE}\""
-
-  notify_when_failed:
-    runs-on: ubuntu-latest
-    name: Notify about failure
-    needs: [pr_info, create_backport_pull_request]
-    if: ${{ failure() }}
-    steps:
-      - uses: actions/github-script@v4
-        with:
-          script: |
-            github.issues.createComment({
-              issue_number: ${{ needs.pr_info.outputs.number }},
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              body: '@${{ needs.pr_info.outputs.author }} could not automatically create a backport PR 😩'
-            })

.github/workflows/backport.yml

+# Cherry-picks commits from current branch to a specified one in a command "@metabase-bot backport release-x.40.x"
+name: Backport
+
+on:
+  issue_comment:
+    types: [created]
+
+jobs:
+  create_pull_request:
+    name: Creates a pull request
+    if: contains(github.event.comment.body, '@metabase-bot backport')
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/github-script@v4
+        id: branch_info
+        with:
+          script: |
+            // Example: @metabase-bot backport release-x.40.x
+            const [_botName, _command, targetBranch] = context.payload.comment.body.split(" ");
+            console.log(`Target branch is ${targetBranch}`);
+
+            const { data: originalPullRequest } = await github.pulls.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: context.payload.issue.number,
+            });
+
+            const { data: commits } = await github.pulls.listCommits({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: context.payload.issue.number,
+            });
+
+            const targetRef = await github.git.getRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref: `heads/${targetBranch}`,
+            });
+
+            const backportBranch = `backport-${originalPullRequest.head.ref}`
+
+            try {
+              await github.git.getRef({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                ref: `heads/${backportBranch}`,
+              });
+            } catch(e) {
+              if (e.status === 404) {
+                await github.git.createRef({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  ref: `refs/heads/${backportBranch}`,
+                  sha: targetRef.data.object.sha,
+                });
+              }
+            }
+
+            return {
+              backportBranch,
+              targetBranch,
+              originalPullRequest,
+              startSha: commits[0].sha,
+              endSha: commits[commits.length - 1].sha
+            }
+      - uses: actions/checkout@v2
+        name: Cherry-pick commits and create PR
+        with:
+          fetch-depth: 0
+      - run: |
+          git config --global user.email "metabase-github-automation@metabase.com"
+          git config --global user.name "$GITHUB_ACTOR"
+
+          git fetch --all
+
+          git checkout "${BACKPORT_BRANCH}"
+          git reset --hard origin/${TARGET_BRANCH}
+
+          if [[ -z $(git ls-remote --heads origin ${ORIGINAL_HEAD_REF}) ]]; then
+            echo "PR has been merged, searching for a squashed commit in the base branch"
+            echo "searching for a commit in a ${ORIGINAL_BASE_REF} that contains pull request number ${ORIGINAL_PULL_REQUEST_NUMBER}"
+            SQUASHED_COMMIT=$(env -i git log ${ORIGINAL_BASE_REF} --grep="(#${ORIGINAL_PULL_REQUEST_NUMBER})" --format="%H")
+            echo "found commit ${SQUASHED_COMMIT}"
+            git cherry-pick ${SQUASHED_COMMIT}
+          else
+            echo "PR has not been merged, copying all commits"
+            git cherry-pick ${ORIGINAL_BASE_SHA}..${ORIGINAL_HEAD_SHA}
+          fi
+
+          git push origin "${BACKPORT_BRANCH}" --force-with-lease
+
+          if [[ $(hub pr list -b "${TARGET_BRANCH}" -h "${BACKPORT_BRANCH}" -s "open") ]]; then
+              echo "PR already exists"
+          else
+              hub pull-request -b "${TARGET_BRANCH}" -h "${BACKPORT_BRANCH}" -l "auto-backported" -a "${GITHUB_ACTOR}" -F- <<<"🤖 backported \"${ORIGINAL_TITLE}\"
+
+              #${ORIGINAL_PULL_REQUEST_NUMBER}"
+              echo "New PR has been created"
+          fi
+        env:
+          ORIGINAL_TITLE: ${{ fromJson(steps.branch_info.outputs.result).originalPullRequest.title }}
+          ORIGINAL_BASE_REF: ${{ fromJson(steps.branch_info.outputs.result).originalPullRequest.base.ref }}
+          ORIGINAL_BASE_SHA: ${{ fromJson(steps.branch_info.outputs.result).originalPullRequest.base.sha }}
+          ORIGINAL_HEAD_REF: ${{ fromJson(steps.branch_info.outputs.result).originalPullRequest.head.ref }}
+          ORIGINAL_HEAD_SHA: ${{ fromJson(steps.branch_info.outputs.result).originalPullRequest.head.sha }}
+          ORIGINAL_PULL_REQUEST_NUMBER: ${{ fromJson(steps.branch_info.outputs.result).originalPullRequest.number }}
+          TARGET_BRANCH: ${{ fromJson(steps.branch_info.outputs.result).targetBranch }}
+          BACKPORT_BRANCH: ${{ fromJson(steps.branch_info.outputs.result).backportBranch }}
+          START_SHA: ${{ fromJson(steps.branch_info.outputs.result).startSha }}
+          END_SHA: ${{ fromJson(steps.branch_info.outputs.result).endSha }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  notify_when_failed:
+    runs-on: ubuntu-latest
+    name: Notify about failure
+    needs: create_pull_request
+    if: ${{ failure() }}
+    steps:
+      - uses: actions/github-script@v4
+        with:
+          script: |
+            const { GITHUB_SERVER_URL, GITHUB_REPOSITORY, GITHUB_RUN_ID} = process.env;
+            const runUrl = `${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}`
+            const author = context.payload.comment.user.login;
+
+            github.issues.createComment({
+              issue_number: context.payload.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body: `@${author} could not automatically a backport PR 😩 [[Logs]](${runUrl})`
+            })