backport

How it works

1. Select a commit to backport
2. Select a branch to backport to
3. The commit will be cherrypicked, pushed and a pull request created.

Requirements

• Node 16 or higher
• git

Install

npm install -g backport

After installation you should add an access token to the global config in ~/.backport/config.json. See the documentation for how the access token is generated.

Quick start

npm install backport

Add a project config to the root of your repository:

// .backportrc.json
{
  "repoOwner": "elastic",
  "repoName": "kibana",

  // the branches available to backport to
  "targetBranchChoices": ["main", "6.3", "6.2", "6.1", "6.0"],

  // Optional: Automatically detect which branches a pull request should be backported to based on the pull request labels.
  // In this case, adding the label "backport-to-production" will backport the PR to the "production" branch
  "branchLabelMapping": {
    "^backport-to-(.+)quot;: "$1"
  }
}

Add personal access token to global config:

// ~/.backport/config.json
{
  "accessToken": "ghp_very_secret"
}

Run:

npx backport

This will start an interactive prompt. You can use your keyboards arrow keys to choose options, <space> to select checkboxes and <enter> to proceed.

Config options

See configuration.md

CLI options

Option	Shorthand notation	Description	Default
--access-token		Github access token
--all	-a	Show commits from any author	false
--assignee	--assign	Assign users to the target PR
--author		Filter commits by Github username. Opposite of --all	Current user
--auto-assign		Assign current user to the target PR	false
--branch	-b	Target branch to backport to
--ci		Disable interactive prompts	false
--config-file		Custom path to project config file (.backportrc.json)
--dir		Clone repository into custom directory	~/.backport/repositories/
--dry-run		Perform backport without pushing to Github	false
--editor		Editor (eg. code) to open and resolve conflicts	nano
--fork		Create backports in fork repo	true
--git-hostname		Hostname for Git	github.com
--mainline		Parent id of merge commit	1
--max-number	--number, -n	Number of commits to choose from	10
--multiple		Multi-select for commits and branches	false
--multiple-branches		Multi-select for branches	true
--multiple-commits		Multi-select for commits	false
--no-cherrypick-ref		Do not append "(cherry picked from commit...)". Git Docs	false
--no-status-comment		Do not publish a status comment to Github with the results of the backport	false
--no-verify		Bypass the pre-commit and commit-msg hooks	false
--path	-p	Filter commits by path
--pr-description	--description	Description for pull request
--pr-filter		Find PRs using Github's search syntax
--pr-title	--title	Title of pull request
--pull-number	--pr	Backport pull request by number
--repo-name		Name of repository
--repo-owner		Owner of repository
--reset-author		Set yourself as commit author
--reviewer		Add reviewer to the target PR
--sha		Sha of commit to backport
--source-branch		Specify a non-default branch to backport from
--source-pr-label		Labels added to the source PR
--target-branch	-b	Target branch(es) to backport to
--target-pr-label	--label, -l	Labels added to the target PR
--help		Show help
-v, --version		Show version number

The CLI options will override the configuration options.

Backport Module API

backport can be imported as a Node module and interacted with programatically. This can be useful when creating automation around the Backport tool. See for example the Backport Github Action

backportRun

Backport a commit programatically. Commits can be selected via pullNumber or sha.

Arguments:

All of the options listed on configuration.md are valid. The most common options are:

accessToken string (Required)
Github access token to authenticate the request

repoName string (Required)
Name of repository

repoOwner string (Required)
Owner of repository (organisation or username)

pullNumber number
Filter commits by pull request number

sha string
Filter commits by commit sha

ci boolean
Enabling this will disable the interactive prompts

Example

import { backportRun } from 'backport';

const result = await backportRun({
  accessToken: 'abc',
  repoName: 'kibana',
  repoOwner: 'elastic',
  pullNumber: 121633,
  ci: true,
  targetPRLabels: ['backport'],
  autoMerge: true,
  autoMergeMethod: 'squash',
});

console.log(result);

getCommits

Retrieve information about commits and whether they are backported

Arguments:

accessToken string (Required)
Github access token to authenticate the request

repoName string (Required)
Name of repository

repoOwner string (Required)
Owner of repository (organisation or username)

author string
Filter commits by Github user

pullNumber number
Filter commits by pull request number

sha string
Filter commits by commit sha

sourceBranch string
The branch to display commits from. Defaults to the default branch (normally "main" or "master")

Example

import { getCommits } from 'backport';

const commits = await getCommits({
  accessToken: 'abc',
  repoName: 'kibana',
  repoOwner: 'elastic',
  pullNumber: 121633,
});

console.log(commits);

/*
[{
  soureCommit: {
    committedDate: '2021-12-20T14:20:16Z',
    sha: 'd421ddcf6157150596581c7885afa3690cec6339',
    message: '[APM] Add note about synthtrace to APM docs (#121633)',
  },
  sourcePullRequest: {
    number: 121633,
    url: 'https://github.com/elastic/kibana/pull/121633'
    mergeCommit: {
      sha: 'd421ddcf6157150596581c7885afa3690cec6339',
      message: '[APM] Add note about synthtrace to APM docs (#121633)',
    }
  },
  sourceBranch: 'main',
  expectedTargetPullRequests: [
    {
      url: 'https://github.com/elastic/kibana/pull/121643',
      number: 121643,
      branch: '8.0',
      state: 'MERGED'
    }
  ]
}]
*/

The Backport Tool as a Github Action

A Github Action around The Backport Tool for automatically creating backports when pull requests are merged.

What is backporting?

Backporting is the action of taking parts from a newer version of a software system [..] and porting them to an older version of the same software. It forms part of the maintenance step in a software development process, and it is commonly used for fixing security issues in older versions of the software and also for providing new features to older versions.

Source: https://en.wikipedia.org/wiki/Backporting

Who is this tool for?

This tools is for anybody who is working on a codebase where they have to maintain multiple versions. If you manually cherry-pick commits from master and apply them to one or more branches, this tool might save you a lot of time.

backport is a CLI tool that will let you backport commit(s) interactively and then cherry-pick and create pull requests automatically. backport will perform all git operations in a temporary folder (~/.backport/repositories/) separate from your working directory, thereby never interfering with any unstages changes your might have.

Features:

• interactively backport one or more commits to one or more branches with an intuitive UI
• ability to see which commits have been backported and to which branches
• ability to customize the title, description and labels of the created backport PRs
• all git operations are handled in a separate directory to not interfere with unstaged files
• Conflicts are handled gracefully, and hints are provided to help the user understand the source of the conflict
• backport a commit by specifying a PR: backport --pr 1337
• list and backport commits by a particular user: backport --author john
• list and backport commits by a particular path: backport --path src/plugins/chatbot
• list PRs filtered by a query: backport --pr-filter label:backport-v2 (will list commits from PRs with the label "backport-v2")
• forward port commits: backport --source-branch 7.x --branch master (will forwardport from 7.x to master)
• backport merge commits: backport --mainline

Contributing

See CONTRIBUTING.md