Continuous integration/continuous deployment (CI/CD) is a modern software development and deployment methodology that advocates for continuously pushing new commits to repositories and immediately pushing those commits to production. This stands in contrast to other popular development methodologies, such as agile, which favor batching deployments into two-week sprints. While there are advantages and disadvantages to both methodologies, CI/CD pipelines have become significantly more popular with many software development teams over time. Read on to learn about setting up a CI/CD pipeline and why it might be beneficial for your project.
CI/CD Defined
Continuous integration/continuous deployment (CI/CD) are two different terms that are often used in tandem with one another, but they refer to distinct concepts. They’re often used together, so it’s more typical to see CI/CD rather than either of them separately.
Continuous Integration
When it comes to developing software, there are many different schools of thought about how it should be done, particularly when working with a team of developers. This has never been more important than now due to the global pandemic and the rise of remote working. If teams may not be working in the same building or even the same country, how do you keep repositories updated and avoid code merge conflicts?
Well, the truth is that some code conflicts are inevitable. If two developers check out the same script and make different changes to the same bit of code before pushing it back to the repository, how do you determine which changes to keep? This is one of the problems continuous integration tries to solve. Within agile development, components are usually built at the feature level, which means that a feature touching several different files may be pulled from the main repo and not pushed back until a day, or several days, later. Should another developer need access to the same files, teams either must come up with an access priority system or plan development in such a way that developers do not end up simultaneously working on the same file.
Continuous integration is a development methodology that advocates developing and pushing small commits on a regular basis back to the main repository. Code changes should be kept to a minimum and those changes should be directly relevant to whatever feature or issue is presently being worked on. This makes it much easier to test and push new features, as well as providing improved granularity on the rare occasions a roll-back is needed.
Small, regular commits that are limited in scope and pushed back to the repository within a short timeframe minimize the chances of code merge conflicts, which can severely impact developer velocity. It makes individual commits easier to push to production or roll-back and it keeps the main repository running the most up-to-date code at any moment. For these reasons, continuous integration has become very popular as a contemporary development methodology.
Continuous Delivery
The other side of the CI/CD coin is continuous delivery. This is sometimes referred to as continuous deployment. These terms are very closely related, though they are not exactly interchangeable. Our previous post provides an explanation of the differences between continuous delivery and continuous deployment. For this article, we’ll be sticking to discussing continuous delivery.
The reason CI/CD are so often used together is because continuous delivery is somewhat of a natural extension of continuous integration. If continuous integration means that a project’s codebase always contains the most up-to-date code, then it stands to reason that end-users should reap the benefits of new features and code changes as soon as they are ready.
Referring back to agile methodology, changes there are made in large batches across two-week sprints. If a feature is completed early on in a cycle, it still has to wait until the development and testing phases are over before it gets pushed to production. There may be no real reason a feature could not be rolled out early, but it’s difficult and discouraged to stray from the established phases of sprints. Thus, in agile methodology, features may be held back unnecessarily and end-users have to wait longer to start making use of new features. In a highly competitive market, even waiting another week can mean losing ground to a competitor.
Continuous delivery, therefore, advocates for pushing the commits from continuous integration to production as soon as they are received and pass testing. This means that your end-users are always on the bleeding edge of production builds and removes artificial barriers to new feature releases. In very competitive markets, continuous delivery can help teams gain a competitive edge when new features are continuously developed and released.
Due to the significantly increased frequency of commits and the pace of commits being pushed to production, CI/CD pipelines are rarely run as part of a manual process. The real benefits of CI/CD beyond what has already been stated lie in the automation of the CI/CD pipeline.
The Benefits of CI/CD
Some of the benefits of CI/CD have already been mentioned, such as reduced code merge conflicts and greater granularity of commits, which makes both pushing and rolling back small changes between branches and repositories much easier. A smoother pipeline from development to deployment will undoubtedly be welcome by development teams, but what makes CI/CD particularly attractive is how well it works as an automated process.
Automating your CI/CD pipeline can save your team significant manhours that would be otherwise spent merging code commits and pushing code to production. When this is done as part of an agile process, it happens every 2 weeks and therefore gives ample time for teams to do so manually. However, the pace of integration and deployment is so much faster in a CI/CD environment that manual processes simply cannot keep up, which is why so many teams choose to automate their CI/CD pipeline.
Doing so also means that teams can focus their priorities on the business product itself rather than the processes around developing and deploying that product. Once a pipeline has been established, developers can simply push commits whenever they are ready. These commits are then automatically tested and pushed to production provided they pass. It takes some effort to set up a CI/CD pipeline, but once that upfront work has been done, maintenance is pretty minimal.
Implementing Your CI/CD Pipeline
Fortunately, there are plenty of tools and services available that make implementing a CI/CD pipeline easier now than ever before. Here are some of the services that can be used for CI/CD automation:
- Jenkins
- TravisCI
- CircleCI
- TeamCity
- Bamboo
- GitLab
- Github Actions
Each tool and service will have its own process to follow for implementation, but as an example, Github Actions makes it simple to create a CI/CD pipeline from within your repository. Github Actions can be created through a GUI or API and can hook onto almost any event related to your repo. An action can be created that runs when a push is made to a repo. From there, a list of jobs to run and any required dependencies can be programmatically added in a .YAML file.
Building, testing, and publishing across multiple platforms in a single workflow is possible, which vastly reduces the complexity associated with doing so manually. Since these steps are added programmatically, they too can be modified as necessary at any time. This not only makes the actual build and deployment process simpler, but it also codifies it in a way that lets you explicitly state the steps required as part of the build, test and deploy process. These steps are not subject to any of the issues associated with manual deployment processes, such as human error and forgetfulness.
Take Your Deployment to the Next Level with a CI/CD Pipeline
Integrating an automated CI/CD pipeline into an agile project can reap numerous benefits, from much shorter software development life cycles to reduced merge conflicts, increased developer velocity, and more. However, it’s not a simple drop-in replacement and does require some retooling and retraining. That can seem like a large upfront expense that may initially put off some team leads looking into implementing CI/CD.
If that is the case, then ProdPerfect may be able to help. We’ve worked with some of our most talented and forward-thinking clients to help transition from a slower agile posture to CI/CD: our role has been to manage an E2E testing layer which supports CD by testing every build.. CI/CD pipelines have become increasingly popular in contemporary software development but there are challenges and considerations that need to be taken into account when transitioning, from setting up the pipeline to integrating testing, external API calls, and more. But there is a big payoff: CI/CD pipelines is that they are largely set-and-forget, meaning that after the process has been configured and put into action, developers can seamlessly utilize it as part of their regular daily workflow with minimal maintenance.