CI/CD Explained
CI/CD or CICD is the practice of continuously integrating and either delivering or deploying applications. The combined practices of continuous integration, continuous deployment and delivery should be seamless and bridge the gap between development and operations teams by being automated.
Continuous development is a way for engineers and DevOps teams to test if the changes they’ve made to a codebase are ready for deployment through automated testing. The code then passes or fails the test based on prerequisites that a team has set. This automated way of testing saves developers time and minimizes human error.
In the past, development teams would have to manually transfer code from one machine to another and check if it worked as expected. Now, automated deployment and continuous integration tools can take care of this entire process. These tools allow engineering organizations to focus on their core business needs instead of the overhead of infrastructure.
What Is Continuous Integration?
Continuous integration is an automated process that merges code contributions from different developers into a central repository. It's a valuable DevOps practice because it allows continuous testing of new changes to code.
The Difference: Continuous Deployment vs. Continuous Delivery
Continuous development and continuous delivery are terms that are used together frequently and have similar roles. Continuous delivery happens before continuous deployment. In the delivery process, there is a manual step needed before code is released to production. In this step, the code is reviewed for QA.
If it fails the QA check then it will be sent back for developers to continue working on. If it passes the QA process it will be automatically deployed to production through continuous deployment. Together, continuous deployment and continuous delivery is an automated process for the modern end-to-end deployment pipeline.
What Are The Benefits of CI/CD?
It's no secret that software development is hard. But continuous deployment is a game-changer. It lets you react quickly to changing market demands and find the best way to deploy new features and ideas. That means faster fixes to bugs, faster iterations on product features, and faster releases of whole new products.
Real-time customer feedback has the power to impact the future of your product. Deployment pipelines are a way for teams to react quickly to customer feedback, concerns, and requests. With continuous deployment, teams can respond to these things in real-time. If customers want bugs fixed or new features added, it's as easy as updating the code.
Implementing CI/CD With Feature Flags
Feature flags can be used to create a continuous deployment system as they can safely separate the code change from showing the new feature to end-users. With a feature flag, a code change can live in a production environment then be shown to users once the feature flag it’s hidden behind is turned on to be shown to users.
Additionally, if the code does not work as expected, by having it behind a feature flag it can be easily rolled back. You can also reduce risk by using the feature flag to only show the new code to only a small subset of your users. That way you can test for any bugs and gather customer feedback.
CI/CD Best Practices
We all know that CI/CD is important for an engineering team to make sure it keeps up with its most up-to-date product. The following best practices and behaviors will help ensure an engineering team is getting the most value out of a continuous deployment pipeline.
Before software development begins, you should define the specs for each new feature. Once you have this spec, you can write automation tests to match it. Now that the tests are written and the code is tested, you can finally write the deliverables that match your specs. This process ensures code is covered with automated tests from the get-go. This eliminates any opportunity for gaps between what you expect and what your code actually does.
Once a continuous deployment pipeline is in place and running smoothly, manual changes outside of the pipeline should not be made. Doing so will cause problems with the flow of deployments and cause issues with the CD process. The important thing to remember is that if a company deploys code manually, it will break the deploy flow. That’s why developers should not be making manual changes with code. It's also very important that the only way to deploy is through the pipeline.
Containers allow your software to behave the same, no matter where it goes. This eliminates an entire class of issues where your software might work on one machine but behave differently on another. Containers are also very easy to integrate into your CI/CD pipeline so that your code behaves the same, no matter what happens during automated testing or production deployment.