What are CI/CD Tools and how do they work?

DevOps and CI/CD's aim is to help software teams deliver products to users faster while maintaining quality.

A CI/CD tool plays a central role in CI management, coordinating and automating the various stages of the pipeline, from kicking off the process following a commit, to managing the build, triggering automated tests, publishing artifacts and collating and relaying feedback.

Choosing the right continuous integration or continuous development/delivery tool for your organization is an important step in implementing your CI/CD pipeline, so we’ve gathered the key considerations for you to bear in mind.

Integration options

The job of your CI/CD tool is to coordinate activities between a whole host of systems, including version control systems (e.g. Git, Mercurial or Perforce), build tools (e.g. Ant, Maven or Gradle), automated testing frameworks (e.g. NUnit or JUnit), package managers (e.g. NuGet), issue trackers (e.g. Jira, YouTrack or Github) and container platforms (e.g. Docker).

When it comes to building your CI/CD pipeline, there is no one-size-fits-all approach, so it’s essential to have the option to integrate with different tools, whether that’s via built-in support, third party plugins, or APIs that allow you to extend the functionality to suit your needs. Having this flexibility makes it easier to extend your CI/CD platform to other teams within your organization in the future.

Tech stack support

Any continuous integration solutions you choose need to support the programming languages, platforms and frameworks you’re currently using, and leave room for you to adopt new ones in the future. A tool that is actively developed and supported is more likely to be updated with support for new trends.

Interfaces for everyone

While it’s likely that your CI/CD tool's initial users will be developers, a key aspect of the DevOps practice is breaking down silos between different functions and encouraging collaboration between teams.

Tools to implement continuous integration designed with a DevOps culture in mind provide multiple interfaces to support this. Command line interfaces and APIs enable you to integrate with other systems programmatically. At the same time, a well-designed GUI makes it easy for anyone – including product managers and support teams – to understand the status of the latest build and what’s coming through the pipeline.

Customizable

We’ve said there’s no standard design for a CI/CD pipeline, and the reality is they often become more complex over time. It’s common to have multiple routes through a pipeline, with some stages only included if earlier conditions have been met.

Having the facility to configure branching logic, dependencies and conditions means you can achieve complex workflows without having to create many separate pipeline instances, each of which has to be maintained separately.

Feedback

Rapid feedback loops are at the heart of CI management, with results returned from each stage of the pipeline. A continuous integration tool uses that feedback to resolve conditions in the pipeline logic and displays the information back to users, usually on a dashboard.

Support for email notifications and integrations with IDEs or communication platforms (such as Slack) ensure you stay informed of what’s happening without having to check the dashboard. It’s worth ensuring you have the flexibility to configure the alerts you receive, as getting too many risks them becoming background noise.

Infrastructure options

For some enterprises, keeping the codebase on-premises is a hard requirement, so hosting the entire pipeline on your own servers is essential. For others, offloading infrastructure management to a cloud provider is a distinct advantage.

Tools to implement continuous integration that support public cloud providers, such as AWS, Microsoft Azure or Google Cloud, will allow you to scale your build and test activities as needed, without the overhead of provisioning and maintaining additional infrastructure in-house.

Security

A CI/CD pipeline provides access to your source code and environment parameters, and potentially provides access to your production environment, all of which could lead to considerable damage if they fell into the wrong hands.

Securing your pipeline against malicious actors should therefore be a high priority. That includes managing secrets securely, applying the principle of least privilege (for both human and machine users), and monitoring activity across the pipeline. Tools should also provide an audit trail so that you can investigate any unusual behavior.

Performance

One of the benefits of an automated CI/CD pipeline is that it speeds up the time to market for your product, and the performance of your CI/CD tool is therefore a limiting factor. Continuous integration solutions that allow you to parallelize tasks and take advantage of elastic scalability on cloud-hosted infrastructure will help you keep your pipeline fast.

Metrics

Your CI/CD pipeline will evolve as you use it, accruing more tasks and expanding to handle more projects. By monitoring statistics, such as test coverage and failures, build duration and time spent in queues, you can identify areas of your pipeline that may be slowing down the process or stages that could benefit from being redesigned.

Tools that give you access to a range of metrics and the option to generate reports or export them to other tools for analysis will make it easier to keep improving your CI/CD practice.

Support

When choosing any software tool, it’s important to consider the quality of the documentation and whether there’s a thriving developer community where you’ll be able to ask questions and exchange ideas.

For many enterprises, a paid support option that ensures you can get assistance when you need it by email or online, is a requirement for any product or service that is on the critical path to market.

Testing frameworks support

CI/CD testing tools are software applications that are specifically designed to support continuous integration and continuous delivery/deployment (CI/CD) practices. These tools automate the testing and deployment process, allowing developers to more easily and quickly verify that changes to the codebase are working as expected.

It’s important for a CI/CD testing tool to support testing frameworks that are in use at your organization.

Cost

When comparing the cost of a CI/CD platform, the license fee is only part of the equation. Ease of use and the level of support available will have a considerable impact on the time you spend setting up and maintaining your pipeline over the longer term. If you’re expecting to scale up in future, the ease of moving to cloud-hosted infrastructure is also worth bearing in mind.

Conclusion

DevOps is often described as requiring three key elements to put it into practice: culture, processes, and tools. Choosing the right build and deployment tools for your organization will help you realize the benefits of CI/CD and allow you to keep evolving and improving your software development process and CI management.