What Is CI/CD?
Continuous Integration / Continuous Delivery (CI/CD) is a development process for producing and releasing applications. The CD part of CI/CD sometimes also refers to continuous deployment. The goal of CI/CD is to increase the speed and efficiency of development and deployment.
A key component of CI/CD is the use of automation. Automation enables teams to increase productivity, standardize processes, and reduce tedious, repetitive work. This automation is applied as a pipeline you use to process work. A pipeline is a collection of scripts that serve as a set of instructions for automated tools.
The other key component of CI/CD is a version control process, such as GitFlow. Version control separates your primary codebase from feature branches, which are merged (added to the codebase) when ready. It enables you to reduce feature conflicts and to easily rollback your codebase when a breaking issue is introduced. GitFlow is a method of managing your codebase that uses a branching model to enable parallel development. Using GitFlow, you have a master branch of code that has been approved and branches with proposed changes.
The CI Process
Continuous Integration (CI) employs automation tools for building and testing code you wish to merge with your master branch. Automated testing enables you to test sections of code significantly faster than you can do manually. Early testing and identification of issues enable developers to correct issues faster.
In CI workflows, code is merged as frequently as possible to prevent large issues from arising. Small changes are faster and easier to verify. Frequent merges ensure developers are working on the most up to date product. This makes it easier to ensure any new code they develop is compatible with the master branch.
The CD Processes
Continuous Delivery (CD) is a process in which developers produce code changes in short cycles. Short development cycles reduce the time that it takes to code and test new features, minimizing time to production.
CD ensures that an application can be released on demand and that you can make new features available with minimal notice. Multiple small releases decrease the chance that an update will “break” an application or system. It also limits the number of bugs that can arise with each update. With continuous delivery, deployment is triggered manually.
Continuous deployment ensures the constant, automated deployment of changes. It works best for internal applications where all use cases can be tested before deployment or where stability is not as critical.
You can use continuous deployment in addition to continuous delivery by placing a manual review between the two processes. Using these processes in sequence enables you to benefit from automated deployment while ensuring that quality standards are met.
Tips for Improving Your CI/CD Pipeline
One of the appealing aspects of CI/CD is its flexibility. You can fully customize CI/CD processes to meet your needs and standards. To gain the greatest benefit from these customizations, consider adopting the following best practices.
Use Your Pipeline for All Deployments
When you need immediate patches or changes, it can be tempting to apply them ad hoc. You can apply ad hoc fixes more quickly, since you skip the CI/CD process. However, these fixes are not merged with your codebase and will be overwritten with your next deployment. This type of overwriting reintroduces the original issue and duplicates work.
When changes are applied outside of the pipeline, you no longer have access to automated testing. If you start going around the pipeline you will lose the benefits of standardization and complicate future merge processes. Uniformly using your pipeline helps you ensure uniform software quality and increase efficiency in the long run.
Secure Your Environments
Your CI/CD pipelines include access to your entire codebase and deployment processes. This access makes pipelines an appealing target for attackers so security is vital. Successful attacks could inject malicious code, deploy malware, or allow the theft of proprietary code. To maintain security, all of these must be prevented.
To secure your pipelines, consider using Virtual Private Networks (VPNs) and network access controls. VPNs and access controls enable you to isolate your systems and restrict traffic flow. It is also important to put measures in place to restrict lateral movement. Limit traffic between your pipelines and services with multiple layers of authentication. It is also important to limit access permissions to those required for functionality.
Streamline Your Testing
While automated testing eliminates manual work, it is not necessarily more efficient. To benefit from automation, you need to carefully choose and schedule your tests. Carefully evaluate which tests are run and in which cases. Try to eliminate tests with low value or indeterminate conclusions which are more likely to waste than save time. Remember, not all tests are useful in every case.
Prioritize your fastest tests to gain faster results. Running faster tests first can help you identify the majority of issues early on. Early identification enables you to more quickly fix issues and reduces the chance that you have to roll back significant changes. It can also save time that would be spent running complex tests unnecessarily.
You should also ensure that developers run local tests before making merge requests. Local tests ensure that code is internally valid. After local tests are performed, you can more quickly verify compatibility with the master branch. Local tests are typically significantly faster to run than merge compatibility tests.
Refine Your Pipelines
Pipelines are meant to eliminate the duplication of manual work but can be a cause of wasted effort, if you aren’t careful. When you are running multiple pipelines, much of the scripting is the same across pipelines.
Rather than writing scripts multiple times, you can maintain a Git repository of commonly used scripts. A repository can reduce duplicate work, reduce the amount of tool expertise needed to assemble a pipeline, and standardize processes.
It can also be useful to parameterize pipeline scripts. Parameterizing uses references to sources rather than duplicating code. Using parameters makes it easier to manage and update your scripts and reduces the number of scripts needed.
CI/CD pipelines can increase productivity and the quality of software products, if used correctly. When created haphazardly, pipelines become a process that only gets in your way. Hopefully, this article helped you understand how CI/CD pipelines can benefit you. When developing your pipelines, try to apply these best practices to ensure that your pipelines are a benefit and not a burden.