When we talk about a CI/CD pipeline, we’re referring to the process that takes code from your development environment through various steps like testing and staging, ultimately delivering it into your users’ hands.

The aim of CI/CD is to execute this process regularly – multiple times per day or even per hour – so it’s essential to automate as much of your CI/CD pipeline as possible. If a step completes successfully, it should trigger the next one automatically. If a step fails, that feedback should be communicated quickly so the problem can be fixed.

Automating your CI/CD pipelines not only speeds up the overall process of building, testing, and deploying software, but it also ensures that each step is performed consistently and reliably.

The first step in adopting continuous integration is to get your entire codebase into a version control system or VCS (aka source control management or SCM), such as Git, Mercurial, or Perforce, and then to get everyone on your team into the habit of committing their changes frequently. Each commit to main initiates the continuous integration pipeline, building and testing the code to provide rapid feedback on the latest changes.

While frequent commits are an important practice in the CI/CD pipeline, if you’re working on a larger feature that will take several days or weeks to complete, then committing periodically during that process can feel slightly counterproductive.

On the one hand, pushing your changes through the pipeline in regular increments provides you with rapid feedback. It also makes complex merge conflicts less likely than if you wait until you’ve completed the feature.

On the other hand, pushing unfinished features through the pipeline might not be ideal. Sharing incomplete work with users, even in staging environments, might not be desirable either.

Feature flags and feature branches offer ways around this issue. With feature flags, you specify the environments in which your code is visible to users. Your changes are still committed to main and visible to your team, but you decide when the functionality becomes available in staging and production.

Feature branches allow you to develop your feature in a separate branch without losing out on the benefits of automated builds and tests. By triggering the CI/CD pipeline on each commit to a feature branch, just as you would with a commit to main, you can get rapid feedback on what you’ve built.

For the results of your automated tests to be reliable, you need to ensure they run consistently.

Ideally, your test environments should be configured to resemble production as closely as possible, and they should be reset between test runs to avoid environmental inconsistencies disrupting your test results.

Virtual machines (VMs) have long been a popular choice for running test environments, as you can script the process of refreshing them for each new build under test.

However, tearing down and spinning up new VMs takes time, while your scripts will need to include configuration for each virtual environment to provide all the dependencies the software needs to run. When new dependencies are added, the environment scripts will need to be updated – an easy detail to miss until you’re wondering why your build won’t run.

You can avoid these issues by packaging your code in a container as part of the initial build step. A container includes all the dependencies that the software needs to run, making it highly portable and easier to deploy to different environments.

If you’re hosting your CI/CD pipelines on your own infrastructure, you’ll still need VMs to deploy the containers to, but there is less work involved in preparing the test environments. If you’re running your pipeline in the cloud, using containers means you can take advantage of managed services and offload the infrastructure management to your cloud provider.

The number of testing and staging environments in your pipeline architecture will depend on what you’re building and the needs of the different stakeholder groups in your organization. Examples include exploratory testing, security reviews, user research, sales demos, training environments, and sandboxes for support staff to replicate customer issues.

Automating the creation of and deployment to these environments is more efficient than refreshing them manually. You can also configure different pipeline triggers for different environments.

For example, while your test environments might be updated with every build, you may decide to refresh staging environments less frequently – perhaps once a day or once a week with the latest successful build.

Once your code changes have passed each of the previous pipeline stages successfully, they are ready for release to production. This final step can be either manual or automatic.

Releasing manually (continuous delivery) is useful if:

• You want to control when new features or functionality are made available.
• Your deployment process involves downtime for your users.
• Users need to install your product, and you want to batch up changes for delivery on a regular release schedule.

With continuous deployment, the release is automatic. Changes go live providing they have passed all previous stages. For larger teams that commit frequently, this can mean deploying updates to users dozens of times per day – a feat that is practically impossible without an automated pipeline.

CI/CD forms part of a wider practice known as DevOps. Combining development (creating software products and services) with operations (releasing and maintaining that software), DevOps is both a way of working and a mindset. It builds on Agile principles to help the wider organization – not just development teams – deliver quality software faster.

When implementing your CI/CD pipelines, understanding what DevOps means will help you get started. The following points are worth bearing in mind:

• DevOps emphasizes the importance of aligning everyone involved in the creation, release, and maintenance of software around a common goal: delivering working software that meets users’ needs.
• Central to a DevOps approach is the concept of shifting left. This means finding out about problems as early as possible so they don’t create delays later in the process. That’s why CI/CD focuses on regular and rapid feedback loops, which help you shift left.
• Bringing developer skills and expertise into operations opens up the possibility of automating tasks like maintaining infrastructure and refreshing environments.
• By exposing development teams to work typically handled by operations teams, developers gain visibility into the entire process, allowing them to proactively address bugs and user feedback.

With CI/CD pipelines, you can automate what happens from when you commit changes to when you release a new version of your software. Automating these tasks accelerates execution, delivering feedback faster, which in turn allows necessary action to be taken earlier, potentially saving valuable time and resources.

CI/CD is a DevOps practice that uses automation to provide rapid feedback on each stage of the software development life cycle. Discovering issues introduced by your latest code changes makes software development more efficient. By shifting left (moving interactions earlier and getting feedback sooner), you are empowered to fail fast, and building an automated pipeline helps put these techniques into practice.

When it comes to designing your own CI/CD process, it’s a good idea to build it up in stages, starting with continuous integration. The exact stages of the pipeline and the logic determining when each stage is triggered depend on your product and your organization.

Choosing a CI/CD platform that provides the flexibility to configure your pipeline for your unique requirements, while still being easy to manage, will help you forge a dependable release process and improve the quality of your software.

TeamCity is a CI/CD solution designed for a DevOps way of working. With support for all leading version control systems, a wide range of build, test, and package management tools, as well as popular VM and container management platforms, TeamCity helps you transform your existing processes into automated CI/CD pipelines.

Flexible trigger options and a visual pipeline editor make it easy to configure pipelines for any workflow. Configurations are automatically stored as code, giving you the freedom to build your logic in the GUI while leveraging all the benefits of configuration as code.

Thanks to TeamCity’s high-performance design, a single build server can handle thousands of projects. On-premises and cloud-native deployment options give you the flexibility to run your pipelines where you want and scale up on demand. Test parallelization and real-time results shorten feedback loops even more, helping you fail fast for a more productive developer experience.