Integrate bot for cherry-picking / backporting commits to release branches

.github/scripts/backport.js

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+module.exports = async ({ github, context, core }) => {
+const branches = JSON.parse(process.env.BRANCHES_JSON || '[]');
+
+// Get PR number from event
+const prNumber = context.payload.pull_request?.number || context.payload.issue.number;
+
+// Fetch full PR data (needed when triggered via issue_comment)
+const { data: pullRequest } = await github.rest.pulls.get({
+  owner: context.repo.owner,
+  repo: context.repo.repo,
+  pull_number: prNumber
+});
+
+const prTitle = pullRequest.title;
+const prAuthor = pullRequest.user.login;
+
+// Validate PR is merged
+if (!pullRequest.merged) {
+  // If triggered by a comment on an unmerged PR, acknowledge and exit gracefully
+  if (context.eventName === 'issue_comment') {
+    core.info('PR is not merged yet. Acknowledging /cherry-pick command and will backport after merge.');
+    // Add a reaction to the comment
+    await github.rest.reactions.createForIssueComment({
+      owner: context.repo.owner,
+      repo: context.repo.repo,
+      comment_id: context.payload.comment.id,
+      content: 'eyes'
+    });
+    // Add a comment explaining what will happen
+    await github.rest.issues.createComment({
+      owner: context.repo.owner,
+      repo: context.repo.repo,
+      issue_number: prNumber,
+      body: `👀 Backport request acknowledged for: ${branches.map(b => `\`${b}\``).join(', ')}\n\nThe backport PR(s) will be automatically created when this PR is merged.`
+    });
+    return [];
+  }
+  core.setFailed('PR is not merged yet. Only merged PRs can be backported.');
+  return;
+}
+
+// Get all commits from the PR
+const { data: commits } = await github.rest.pulls.listCommits({
+  owner: context.repo.owner,
+  repo: context.repo.repo,
+  pull_number: prNumber
+});
+
+if (commits.length === 0) {
+  core.setFailed('No commits found in PR. This should not happen for merged PRs.');
+  return;
+}
+
+core.info(`Backporting PR #${prNumber}: "${prTitle}"`);
+core.info(`Commits to cherry-pick: ${commits.length}`);
+commits.forEach((commit, index) => {
+  core.info(`  ${index + 1}. ${commit.sha.substring(0, 7)} - ${commit.commit.message.split('\n')[0]}`);
+});
+
+const { execSync } = require('child_process');
+
+const results = [];
+
+for (const targetBranch of branches) {
+  core.info(`\n========================================`);
+  core.info(`Backporting to ${targetBranch}`);
+  core.info(`========================================`);
+  const backportBranch = `backport-${prNumber}-to-${targetBranch}`;
+  try {
+    // Create backport branch from target release branch
+    core.info(`Creating branch ${backportBranch} from ${targetBranch}`);
+    execSync(`git fetch origin ${targetBranch}:${targetBranch}`, { stdio: 'inherit' });
+    execSync(`git checkout -b ${backportBranch} ${targetBranch}`, { stdio: 'inherit' });
+    // Cherry-pick each commit from the PR
+    let hasConflicts = false;
+    for (let i = 0; i < commits.length; i++) {
+      const commit = commits[i];
+      const commitSha = commit.sha;
+      const commitMessage = commit.commit.message.split('\n')[0];
+      core.info(`Cherry-picking commit ${i + 1}/${commits.length}: ${commitSha.substring(0, 7)} - ${commitMessage}`);
+      try {
+        execSync(`git cherry-pick -x ${commitSha}`, { 
+          encoding: 'utf-8',
+          stdio: 'pipe'
+        });
+      } catch (error) {
+        // Check if it's a conflict
+        const status = execSync('git status', { encoding: 'utf-8' });
+        if (status.includes('Unmerged paths') || status.includes('both modified')) {
+          hasConflicts = true;
+          core.warning(`Cherry-pick has conflicts for commit ${commitSha.substring(0, 7)}.`);
+          // Add all files (including conflicted ones) and commit
+          execSync('git add .', { stdio: 'inherit' });
+          try {
+            execSync(`git -c core.editor=true cherry-pick --continue`, { stdio: 'inherit' });
+          } catch (e) {
+            // If continue fails, make a simple commit
+            execSync(`git commit --no-edit --allow-empty-message || git commit -m "Cherry-pick ${commitSha} (with conflicts)"`, { stdio: 'inherit' });
+          }
+        } else {
+          throw error;
+        }
+      }
+    }
+    // Push the backport branch
+    core.info(`Pushing ${backportBranch} to origin`);
+    execSync(`git push origin ${backportBranch}`, { stdio: 'inherit' });
+    // Create pull request
+    const commitList = commits.map(c => `- \`${c.sha.substring(0, 7)}\` ${c.commit.message.split('\n')[0]}`).join('\n');
+    const prBody = hasConflicts 
+      ? `🤖 **Automated backport of #${prNumber} to \`${targetBranch}\`**
+
+⚠️ **This PR has merge conflicts that need manual resolution.**
+
+Original PR: #${prNumber}
+Original Author: @${prAuthor}
+
+**Cherry-picked commits (${commits.length}):**
+${commitList}
+
+**Next Steps:**
+1. Review the conflicts in the "Files changed" tab
+2. Check out this branch locally: \`git fetch origin ${backportBranch} && git checkout ${backportBranch}\`
+3. Resolve conflicts manually
+4. Push the resolution: \`git push origin ${backportBranch}\`
+
+---
+<details>
+<summary>Instructions for resolving conflicts</summary>
+
+\`\`\`bash
+git fetch origin ${backportBranch}
+git checkout ${backportBranch}
+# Resolve conflicts in your editor
+git add .
+git commit
+git push origin ${backportBranch}
+\`\`\`
+</details>`
+      : `🤖 **Automated backport of #${prNumber} to \`${targetBranch}\`**
+
+✅ Cherry-pick completed successfully with no conflicts.
+
+Original PR: #${prNumber}
+Original Author: @${prAuthor}
+
+**Cherry-picked commits (${commits.length}):**
+${commitList}
+
+This backport was automatically created by the backport bot.`;
+
+    const newPR = await github.rest.pulls.create({
+      owner: context.repo.owner,
+      repo: context.repo.repo,
+      title: `[${targetBranch}] ${prTitle}`,
+      head: backportBranch,
+      base: targetBranch,
+      body: prBody,
+      draft: hasConflicts
+    });
+    // Add labels
+    await github.rest.issues.addLabels({
+      owner: context.repo.owner,
+      repo: context.repo.repo,
+      issue_number: newPR.data.number,
+      labels: ['backport', hasConflicts ? 'needs-manual-resolution' : 'auto-backport']
+    });
+    // Link to original PR
+    await github.rest.issues.createComment({
+      owner: context.repo.owner,
+      repo: context.repo.repo,
+      issue_number: prNumber,
+      body: `🤖 Backport PR created for \`${targetBranch}\`: #${newPR.data.number} ${hasConflicts ? '⚠️ (has conflicts)' : '✅'}`
+    });
+    results.push({
+      branch: targetBranch,
+      success: true,
+      prNumber: newPR.data.number,
+      prUrl: newPR.data.html_url,
+      hasConflicts
+    });
+    core.info(`✅ Successfully created backport PR #${newPR.data.number}`);
+  } catch (error) {
+    core.error(`❌ Failed to backport to ${targetBranch}: ${error.message}`);
+    // Comment on original PR about the failure
+    await github.rest.issues.createComment({
+      owner: context.repo.owner,
+      repo: context.repo.repo,
+      issue_number: prNumber,
+      body: `❌ Failed to create backport PR for \`${targetBranch}\`\n\nError: ${error.message}\n\nPlease backport manually.`
+    });
+    results.push({
+      branch: targetBranch,
+      success: false,
+      error: error.message
+    });
+  } finally {
+    // Clean up: go back to main branch
+    try {
+      execSync('git checkout main', { stdio: 'inherit' });
+      execSync(`git branch -D ${backportBranch} 2>/dev/null || true`, { stdio: 'inherit' });
+    } catch (e) {
+      // Ignore cleanup errors
+    }
+  }
+}
+
+// Summary (console only)
+core.info('\n========================================');
+core.info('Backport Summary');
+core.info('========================================');
+for (const result of results) {
+  if (result.success) {
+    core.info(`✅ ${result.branch}: PR #${result.prNumber} ${result.hasConflicts ? '(has conflicts)' : ''}`);
+  } else {
+    core.error(`❌ ${result.branch}: ${result.error}`);
+  }
+}
+return results;
+};
+
+

.github/scripts/extract-branches.js

@@ -0,0 +1,42 @@
+module.exports = async ({ github, context, core }) => {
+  let branches = [];
+
+  // Get PR number
+  const prNumber = context.payload.pull_request?.number || context.payload.issue?.number;
+
+  if (!prNumber) {
+    core.setFailed('Could not determine PR number from event');
+    return [];
+  }
+
+  // Check PR body
+  if (context.payload.pull_request?.body) {
+    const prBody = context.payload.pull_request.body;
+    // Enforce release-X.Y or release-X.Y.Z
+    const bodyMatches = prBody.matchAll(/\/cherry-pick\s+(release-\d+\.\d+(?:\.\d+)?)/g);
+    branches.push(...Array.from(bodyMatches, m => m[1]));
+  }
+
+  // Check all comments
+  const comments = await github.rest.issues.listComments({
+    owner: context.repo.owner,
+    repo: context.repo.repo,
+    issue_number: prNumber
+  });
+
+  for (const comment of comments.data) {
+    const commentMatches = comment.body.matchAll(/\/cherry-pick\s+(release-\d+\.\d+(?:\.\d+)?)/g);
+    branches.push(...Array.from(commentMatches, m => m[1]));
+  }
+
+  // Deduplicate
+  branches = [...new Set(branches)];
+
+  if (branches.length === 0) {
+    core.setFailed('No valid release branches found in /cherry-pick comments');
+    return [];
+  }
+
+  core.info(`Target branches: ${branches.join(', ')}`);
+  return branches;
+};

.github/workflows/cherrypick.yml

@@ -0,0 +1,67 @@
+# Copyright 2025 NVIDIA CORPORATION
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Cherry-Pick
+
+on:
+  pull_request_target:
+    types: [closed]
+  issue_comment:
+    types: [created]
+
+permissions:
+  contents: write
+  pull-requests: write
+  issues: write
+
+jobs:
+  backport:
+    name: Backport PR
+    runs-on: ubuntu-latest
+    # Run on merged PRs OR on /cherry-pick comments
+    if: |
+      (github.event_name == 'pull_request_target' && github.event.pull_request.merged == true) ||
+      (github.event_name == 'issue_comment' && github.event.issue.pull_request && startsWith(github.event.comment.body, '/cherry-pick'))
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract target branches from PR comments
+        id: extract-branches
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const run = require('./.github/scripts/extract-branches.js');
+            return await run({ github, context, core });
+
+      - name: Configure git
+        run: |
+          git config user.name "nvidia-backport-bot"
+          git config user.email "noreply@nvidia.com"
+
+      - name: Backport to release branches
+        id: backport
+        uses: actions/github-script@v7
+        env:
+          BRANCHES_JSON: ${{ steps.extract-branches.outputs.result }}
+        with:
+          script: |
+            const run = require('./.github/scripts/backport.js');
+            return await run({ github, context, core });
+
+