├── packages/
│ ├── project1/ # First project or component
│ │ ├── src/ # Source code
│ │ ├── tests/ # Test code
│ │ ├── package.json # Project-specific dependencies
│ │ └── ...
│ ├── project2/ # Second project or component
│ │ ├── src/
│ │ ├── tests/
│ │ ├── package.json
│ │ └── ...
│ ├── shared/ # Shared code and utilities
│ └── ...
├── .gitignore # Gitignore file
├── package.json # Root package.json for managing monorepo dependencies
├── lerna.json # Lerna configuration file (if using Lerna)
├── README.md # Monorepo documentation
└── ...other project files
Choosing this type of architecture has some major advantages over its counterparts below are the most useful advantages.
- Code Sharing : In a monorepo, all your code is stored in a single repository. This makes it easy to share code and libraries across different projects within your organization. It encourages code reuse and minimizes duplication.
- Easier Dependency Management : Managing dependencies in a monorepo is often more straightforward compared to multiple repositories. You can have a centralized way to manage dependencies, making it easier to update and maintain them.
- Easy visibility : Using a monorepo, it’s easier to standardize code and tooling across the teams. The single view of the whole code available in a monorepo increases discoverability of status and changes. This results in smoother release management and easier refactoring.
- Streamlined Testing and CI/CD : Continuous integration and continuous deployment (CI/CD) pipelines can be set up more efficiently in a monorepo. Testing changes across multiple projects becomes more manageable, and you can deploy related changes together.
- Atomic Commits: Monorepo encourage atomic commits, meaning that changes to multiple projects can be bundled together in a single commit. This makes it easier to track changes, perform rollbacks, and maintain a clear history of your codebase.
- Standardization : With monorepo, it is easier to standardize code and tooling across the teams. You can create policies that keep your main branch uncluttered, limit access to specific branches, enforce naming guidelines, include code reviewers, and enforce best practices. Branch policies keep in-progress work isolated from completed work.
- Release management : A monorepo retains all the information about how to deploy the whole system. An automated build and deploy pipeline doesn't hide deployment knowledge within each team the way it does in a poly-repo.
- Easier refactoring : Direct access to all microservices makes it easier to refactor the code in a monorepo. Also, you can change the code structure. Moving the source code between folders and sub-folders is much easier than moving the source code between multiple repositories.
- Reduced Git Overhead : Managing multiple repositories can lead to Git overhead, especially when dealing with a large number of repositories. In a monorepo, you have a single Git repository to manage.
Decision to use a monorepo should consider your specific project requirements, team size, development processes, and the tools available but this can also create some problems which are as follows
- Complexity : Managing a monorepo can be complex, especially for large projects or organizations. As the codebase grows, it can become challenging to maintain a clear project structure and ensure that everything remains organized.
- Build Times : In a monorepo, changes to one component can trigger the need to rebuild and test multiple other components. This can lead to longer build times, which can be frustrating for developers, especially when they're only working on a small part of the codebase.
- Tooling and CI/CD Complexity : Setting up and maintaining tooling for a monorepo can be more complex than managing separate repositories. Continuous integration and continuous deployment (CI/CD) pipelines may require special configuration to handle the monorepo structure effectively.
- Access Control : Managing access control and permissions in a monorepo can be challenging. Not all developers may need access to all parts of the codebase, and defining granular access control can be more difficult.
- Merge Conflicts : With multiple developers working on different parts of the monorepo, merge conflicts can become more frequent and complex. Resolving these conflicts can be time-consuming.
- Tooling and Language Limitations : Some development tools and languages are better suited for monorepo than others. If your technology stack is not well-suited for monorepo development, you may encounter limitations.
- Risk of Monolithic Behavior : In some cases, a monorepo can lead to monolithic behavior, where it becomes challenging to modularize components effectively. This can result in tightly coupled code, making it harder to maintain and scale the system.
- Team Independence : Teams working on different components within a monorepo may have less independence in terms of their development and release cycles. This can lead to coordination challenges.
- Migration Complexity : If you decide to move from a monorepo to a multi-repo setup or vice versa, it can be a complex and time-consuming process, potentially disrupting development workflows.
In a monorepo, you'll perform various operations to manage and work with the multiple projects or components within a single repository. Here are different monorepo operations:
-
Adding a New Project/Component:
- This operation involves adding a new project or component to the monorepo. You'll typically create a new directory or folder for the component and configure it to work within the monorepo structure.
-
Committing Changes:
- Committing changes in a monorepo is similar to committing changes in a regular Git repository. Developers make changes to the codebase and commit them with descriptive messages.
-
Building:
- Building in a monorepo involves compiling or preparing the code for execution. Depending on your project structure, you may have a single build command that builds all projects or individual commands for each component.
-
Testing:
- Testing operations in a monorepo include running unit tests, integration tests, and end-to-end tests for individual projects or the entire codebase. This ensures that changes don't introduce regressions.
-
Dependency Management:
- Managing dependencies is crucial in a monorepo. You may use a tool like Yarn Workspaces, Lerna, or custom scripts to manage dependencies for each project and ensure consistent versions.
-
Versioning:
- Versioning operations involve defining and managing version numbers for the monorepo and its individual components. You may use semantic versioning (SemVer) or a custom versioning scheme.
-
Pull Requests and Code Reviews:
- Developers submit pull requests (PRs) for changes they've made to the codebase. Code reviews are conducted to ensure code quality and adherence to coding standards before merging the changes.
-
Merging Changes:
- After code reviews and testing, changes are merged into the main branch of the monorepo. Care must be taken to resolve any merge conflicts that may arise.
-
Continuous Integration (CI):
- CI operations involve setting up automated build and testing pipelines for the monorepo. CI tools like Jenkins, Travis CI, or GitHub Actions can be configured to monitor changes and trigger builds and tests.
-
Continuous Deployment (CD):
- CD operations automate the deployment of changes to production or staging environments. Deployments can be triggered automatically or manually after successful CI.
-
Code Reuse:
- Monorepo encourage code reuse. Developers can import and use code from one project in another, which reduces duplication and promotes a modular architecture.
-
Code Organization:
- Organizing code within the monorepo is an ongoing operation. You need to maintain a clear directory structure and naming conventions to keep the codebase organized and easy to navigate.
-
Access Control:
- Managing access control is crucial to ensure that only authorized users have access to specific projects or components within the monorepo. Git permissions and access management tools can be used.
-
Documentation:
- Keeping documentation up-to-date is essential in a monorepo. Developers should document project-specific details, APIs, and guidelines for working with the codebase.
-
Monitoring and Logging:
- Monitoring and logging operations help track the performance and behavior of the monorepo in production. Tools like Prometheus and Grafana can be used for monitoring.
-
Backup and Disaster Recovery:
- Regularly backing up the monorepo and having a disaster recovery plan in place is crucial to prevent data loss in case of unexpected issues.
-
Maintenance and Upgrades:
- Keeping dependencies, tools, and libraries up-to-date is an ongoing operation. This ensures that the monorepo remains secure and compatible with the latest technologies.
-
Scaling:
- As the monorepo grows, you may need to implement strategies for scaling, such as optimizing build times, improving testing processes, and managing larger codebase effectively.
These operations are fundamental for managing a monorepo efficiently. Depending on your specific development workflow and tools, you may implement variations or additional operations tailored to your project's needs. Mostly the monorepo effectiveness depends upon your project type.