Awesome Monorepo

A curated list of awesome Monorepo tools, software and architectures. Monorepos, short for mono-repositories, are repositories that contain multiple projects, usually related to each other.

Inspired by vinta/awesome-python.

Contents

• Build systems & dependency management tools
• Repository management tools
• Good reads
• Version control systems & add-ons
  • Git
  • Mercurial
• Development process tools
• Notable public monorepos
• Migration tools

Build systems & dependency management tools

• baur builds only changed applications in a monorepo branch and manages build artifacts
• Bazel is Google's monorepo-oriented build system. More on Bazel: awesome-bazel
• Buck is Facebook's monorepo-oriented build system.
• Nx is a build system for TypeScript monorepos and a set of monorepo management tools.
• Please a cross-language build system with an emphasis on high performance, extensibility and reproduceability.
• Pants is a monorepo-oriented build system, used by Twitter, Foursquare and multiple other companies.
• Yarn is a JavaScript dependency management tool that supports monorepos through workspaces.
• pnpm is a JavaScript dependency management tool that supports monorepos through a set of dedicated commands called pnpm multi.
• Lerna is a tool for managing JavaScript projects with multiple packages, built on Yarn.
• Bit is a tool for building and managing JavaScript projects with multiple components, and managing the dependency graph of components.
• OAO is a Yarn-based, opinionated JavaScript monorepo management tool.
• MBT is a build tool with differential build support.
• Bolt Pkg is a super-powered JavaScript project management.
• GitLab CI 11.4 supports running steps based on path changes.
• Symplify/MonorepoBuilder is a PHP monorepo management tool.
• Spago is a PureScript package manager and build tool powered by Dhall and package-sets.
• Tainted is a tool to determine which Go packages need to be rebuilt in a monorepo.
• Nix is a package and distribution build tool with remote caching, predominately used by NixOS.

Repository management tools

• oao
• FBShipIt
• Syncpack allows managing multiple package.json files in Lerna Monorepos.
• wsrun allows running a command in each package of a Yarn workspaces monorepo.
• monorepo-run is a collection of helpers to run scripts in each package of a yarn monorepo with a separated pane per package.
• Builder is a tool that makes it possible to ship the same scripts across projects in a Node.js monorepo. For example, share build and testing scripts across projects.
• Lank is a tool that links packages together in a Node.js monorepo using automatic configuration of NODE_PATH instead of symlinks. Lank also allows you to run the same commands across all (or subsets of all) packages.
• Ultra Runner is a smart script runner and build tool for Lerna, Pnpm, Rush and Yarn. Scripts run concurrently, using the dependency topology. Builds keep track of file changes and are skipped when possible.

Good reads

• Why Google Stores Billions of Lines of Code in a Single Repository
• Advantages and Disadvantages of a Monolithic Repository: A case study at Google
• Why you should use a single repository for all your company’s projects
• Advantages of monorepos

Version control systems & add-ons

Git

Tools

• Git shallow clones let you clone only part of your Git history.
  • How to Use Git Shallow Clone to Improve Performance
  • How to handle big repositories with Git
  • Git clones vs Shallow Git clones
• Git filter-branch let you rewrite a repository's history and prune branches.
  • How to handle big repositories with Git
• Git clone --single-branch
  • How to handle big repositories with Git
• Git sparse-checkout
  • Cloning specific folders from git
  • How to handle big repositories with Git
• Git LFS improves the handling of large files in Git.
• GVFS virtualizes the file system beneath your git repo so that git and all tools see what appears to be a normal repo, but GVFS only downloads objects as they are needed. Windows only.
• SlothFS is similar to GVFS, but read-only. It works on Linux and macOS.
• git subtree merges and splits subtrees from your project into subprojects and back. Part of Git since version 1.7.
  • git subsplit automates and simplifies the process of managing one-way read-only subtree splits.
• splitsh-lite is a very fast git subtree alternative to splits subtrees from your project into subprojects.
• josh is a git server proxy enabling on-the-fly virtualization of repositories.
• go-diff is a handy tool analyzes which packages needed to be rebuilt due to changes.

Scaling info

• Atlassian's Monorepos in Git and How to handle big repositories in Git cover scaling options for Git.

Mercurial

Tools

• hgwatchman and Watchman, replaced by fsmonitor trigger partial, incremental builds when your files change
• Facebook's hg-experimental extensions include better support for large repositories in Hg.

Scaling info

• Scaling Mercurial at Facebook

Development process tools

Code reviews

• Pull Review Hubot plugin to automate pull reviews with lots of configuration options.
• Rietveld is a code review tool by Google used by Chromium.

CI tools

• Incremental CI in Jenkins with Bazel, article by Kristina Chodorow (Bazel team).
• bazel-travis is a minimal setup to use Travis CI in a Bazel monorepo.
• buildpipe is a tool to dynamically generate Buildkite pipelines by looking at changes in projects.
• Codefresh is a CI/CD platform for Docker/Kubernetes that has native Monorepo support
• CI/CD for Microservices Using Monorepos, a post describing a Shippable.com build designed for trigerring builds specific to the microservice that has actually been modified and ones depending on it.

Code ownership

• GitHub's CODEOWNERS can restrict who can approve a pull request that affects a given part of a monorepo.
• Chromium's OWNERS file inspired GitHub's CODEOWNERS.
• Write Guard uses GitHub actions to enforce file-level write access to a monorepo.

Notable public monorepos

• Foursquare's opensource projects
• Stellar's Go monorepo
• Habitat's monorepo
• startup-os monorepo: working examples for Google's Open Source tools (bazel, etc) in a monorepo
• M3 monorepo - Distributed TSDB, Aggregator and Query Engine, Prometheus Sidecar, Metrics Platform
• Entria's Full Stack Playground Monorepo
• Berty's monorepo - React-native mobile App + Golang backend + Gomobile bridge + iOS & Android native drivers + Protobuf
• NixOS's monorepo of packages and modules can be used to incrementally build and deploy Linux machines

Migration tools

• Bazel's migration-tooling repository.
• Gazelle generates Bazel BUILD files automatically for Go packages.
• tomono imports an existing set of Git repositories into a monorepo.
• shopsys/monorepo-tools contains a set of tools for building and splitting a monolithic repository.
• Fastlane monorepo migration tools tools for migrating code and github issues. Specific for fastlane so requires some code changes to use

Development Workflows

• Trunk Based Development, a source-control branching model, where developers collaborate on code in a single branch called ‘trunk’, resist any pressure to create other long-lived development branches by employing documented techniques. They therefore avoid merge hell, do not break the build, and live happily ever after.
• Branch By Abstraction, is a set-piece technique to effect a ‘longer to complete’ change in the trunk.

License

To the extent possible under law, Uriel Corfa has waived all copyright and related or neighboring rights to this work.