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 https://github.com/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.
• 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.

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.

Good reads

• gomonorepo covers tooling and concepts of monorepos, centered around PHP.
• 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.
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• Git filter-branch let you rewrite a repository's history and prune branches.
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• Git clone --single-branch
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• Git sparse-checkout
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• 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.
  • 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.

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.

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

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.