What are the best methods for managing application dependencies in deployment?

1 Use a dependency manager

A dependency manager is a tool that automates the process of downloading, installing, updating, and resolving dependencies for your application. It also keeps track of the specific versions and configurations of the dependencies that your application needs, and stores them in a file or a database. Some examples of dependency managers are npm for Node.js, pip for Python, Maven for Java, and Bundler for Ruby. By using a dependency manager, you can save time and effort, avoid manual errors, and ensure consistency and reproducibility across different environments.

2 Use a container

A container is a lightweight and isolated unit that packages your application and all its dependencies into a single executable image. It runs on a shared operating system, but has its own file system, network, and resources. Some examples of container platforms are Docker, Kubernetes, and Podman. By using a container, you can isolate your application from the host environment, reduce the risk of conflicts or interference, and simplify the deployment and scaling process.

3 Use a virtual environment

A virtual environment is a tool that creates a separate and isolated space for your application and its dependencies on your local machine. It allows you to install and manage different versions and combinations of dependencies without affecting the global system or other projects. Some examples of virtual environment tools are venv for Python, RVM for Ruby, and virtualenv for Python. By using a virtual environment, you can test and debug your application in a controlled and consistent setting, and avoid polluting or breaking your system.

5 Use a lock file

A lock file is a file that records the exact versions and checksums of the dependencies that your application uses at a given point in time. It is usually generated by your dependency manager when you install or update your dependencies, and it should be committed to your version control system. Some examples of lock files are package-lock.json for npm, Pipfile.lock for pipenv, and Gemfile.lock for Bundler. By using a lock file, you can ensure that your application always uses the same and verified versions of the dependencies, and avoid discrepancies or surprises in different environments.