Continuous Delivery: What is it?

Continuous Delivery (CD) is all about getting changes—whether they're bug fixes, new features, or configuration updates—into the hands of end-users as quickly and safely as possible. The ultimate aim is to ensure that deploying to production is a smooth and on-demand process, regardless of the system’s size or complexity. Think of it as an approach where you're always ready for deployment, whether you're pushing out a small "Hello World" app or a massive distributed system.

A key factor in CD is ensuring that necessary resources, such as runtime processing power, are always available when needed.

Before diving deeper, let’s clarify a few essential concepts:

  • Continuous Delivery (CD): This involves a manual trigger for deploying to production.
  • Continuous Deployment: Here, releases to production are automatic.
  • Continuous Integration (CI): This is typically the starting point for both CD and Continuous Deployment, focusing on automatically testing and building new or updated code.

If your deployment process feels slow or frustrating, that's a sign something's wrong!

Continuous Delivery in Practice

As mentioned above, Continuous Delivery is a methodology that allows for smooth delivery of final products. It's a core part of the software development lifecycle (SDLC), and many tech giants—like Amazon, Facebook, Walmart, and Target—have adopted CD for streamlining their processes.

Traditionally, getting software updates to users could be slow, error-prone, and expensive. Continuous Delivery breaks this pattern by:

  • Reducing release management overhead: Developers can deploy updates or bug fixes quickly, with minimal hassle.
  • Faster feedback loops: Thanks to automation, feedback from end-users or QA can be acted upon swiftly, without human intervention.
  • Adapting to market needs: CD allows teams to respond to changes in the market or business strategies without much friction.
  • Streamlined testing and QA: Developers can push updates through testing and QA much faster with CD tools.

How Jenkins Fits into the Picture

Enter Jenkins: one of the most widely used open-source automation servers.

Jenkins shines by offering a vast array of plugins that enable building, testing, deploying, and automating virtually any project. It’s essentially the backbone of many CI/CD pipelines, acting as the glue that holds your automation together.

Thanks to its extensive plugin ecosystem—created by a large developer community—Jenkins can support a variety of programming languages, frameworks, and tools. This makes it a versatile choice for CI/CD compared to other platforms.

Moreover, Jenkins separates responsibilities within the software development lifecycle:

  • Developers focus on writing code.
  • QA teams handle testing and quality assurance, which are automated using Jenkins.

Key Benefits of Jenkins

  • Open-source and completely free to use.
  • Automatically detects issues in tests and builds, providing immediate feedback.
  • Cross-platform: Works seamlessly on Windows, macOS, and Linux.
  • Highly configurable and customizable for any type of project.

A Typical Jenkins Continuous Delivery Pipeline

Here’s a basic overview of how a Continuous Delivery pipeline works with Jenkins:

  1. Update your local codebase: Start by ensuring your local repository is up-to-date with the main codebase (often hosted on platforms like GitHub).
  2. Create a new branch: Check out a new branch to make your changes, and don't forget to include your tests!
  3. Run your tests: If everything passes, you're good to go.
  4. Push your changes: Once your branch is up-to-date, commit and push your changes to the main repository.
  5. Jenkins kicks in: As soon as Jenkins detects changes in the GitHub repository, it automatically starts the build process.
  6. Automated testing: If the tests pass, Jenkins triggers a build automatically.

This flow ensures that your updates make it through testing and into production quickly and reliably.

Setting Up Jenkins for Continuous Delivery

Now that we’ve covered Jenkins’ role in the Continuous Delivery process, it’s time to roll up our sleeves and set up your Jenkins environment.

Ready to get started?