Continuous integration (CI) and continuous delivery/deployment (CD) practices have taken the software development world by storm. And for good reason – it helps software teams release higher quality software faster 🙂
CI/CD is a software delivery practice (some call it a “pipeline”) leveraging automation to achieve improved collaboration and reduced development and deployment timelines from months and weeks to days, hours or even minutes!
It’s revolutionizing the way applications are built, tested, and run. As a result the demand for CI/CD skills has been on the rise over the last several years. And that trend isn’t going away anytime soon.
Whether you’re an aspiring software developer or looking to streamline the software development process in your organization (or for your own project), learning and using up CI/CD framework is something you need to explore.
This article will give you an understanding of the concepts of CI, CD, DevOps, the steps involved in this software delivery pipeline, and the tools that make it happen.
Here is a summary of what you will learn:
- What is a CI/CD Pipeline?
- CI vs CD: What is The Difference?
- What is DevOps?
- Benefits of using CI/CD
- What are the top CI and CD Tools?
- Recommended CI/CD Learning Resources for Beginners
What is a CI/CD Pipeline?
The CI/CD pipeline concept is a software engineering method that speeds up the software development lifecycle by automating the build and release/deployment of code.
That way the people responsible for testing (such as Software Quality Engineers) can test more often. This means bugs are found and potentially fixed sooner. Resulting in higher quality software.
For example, the code contributed by different developers can be automatically integrated into a shared repository. Usually that’s done through a Pull Request (where one developer asks permission to add their code). Once the changes are integrated, a build is auto-generated and then the team has a chance to test that build for defects. And assuming no problems are found or once they are addressed then the build can be released to production.
The term CI/CD is an acronym for Continuous Integration and Continuous Delivery or Continuous Deployment. These are the main concepts in the CI/CD pipeline.
Let’s take a look at what each concept means.
What is Continuous Integration (CI)?
Continuous Integration (CI) is a software development method where code contributed by different members of the development team is automatically merged into a central repository where builds and tests run automatically.
This integration happens frequently. It can happen on a daily or even on an hourly basis.
Merging and testing code this often reduces code compatibility issues and duplicated efforts that can arise when multiple developers are working on a project.
It also goes to ensure all components of a software product work together seamlessly.
What is Continuous Delivery (CD)?
Continuous Delivery (CD) is a software development practice where code changes are continuously tested and kept ready for deployment at any time.
This gives the senior developer, project manager, or product owner a chance to review the code and push it into production manually.
What Is Continuous Deployment (Also CD)
CD can also represent Continuous Deployment, which is a step up from Continuous Delivery.
Instead of waiting for someone to push the tested code to production manually, the changes to the source code are deployed automatically once they pass tests.
CI vs CD: What is the Difference?
Both are important components of the CI/CD pipeline.
The only difference lies in the timing of the processes. CI comes first as it encompasses the processes completed when the developers are writing and merging code.
CD processes happen after the code is integrated. It includes automatically building the code, testing the code, staging it for review, and delivering it to the end users.
As for the people involved, CI falls under developer practices while CD falls in the realm of operations.
What is DevOps?
CI/CD is a central framework in DevOps practices.
DevOps is a modern software development practice that makes use of agile principles to streamline the software development and deployment process.
The term is an acronym for development and operations. It emphasizes collaboration among the IT, development, and operations teams. Again, the idea here with DevOps is to ship software faster, with higher quality and regular or more predictable cadence.
Benefits of using CI/CD
Implementing CI/CD means you’ll need to look at using the right tools, changing embedded practices, and bringing people on board with the idea of thinking in an Agile way.
But the benefits of successful implementation of a CI/CD pipeline make the effort and cost worth it.
These benefits are the reason many organizations are incorporating CI and CD in their development process:
- The main benefit of CI/CD is how it reduces time to release. This shortens the development process and software gets delivered incredibly fast. For example, Amazon delivers new code every few seconds.
- Continuous testing and merging of code minimizes errors. Most bugs are caught and fixed so they never make it to the final production stage.
- This practice also makes developers happy. It promotes teamwork, makes it possible for developers to work together seamlessly, and improves their efficiency and productivity.
- The continuous and thorough testing and speedy deployment ensures customers get to enjoy high quality software and have any bug that might sneak past the testing phase fixed fast. A sure way to keep customers happy and loyal.
- A streamlined software delivery process also improves flexibility and communication, reduces software development costs, and improves the bottom line.
Implementation of a CI/CD Framework
The Stages In The CI/CD Pipeline
Just like the traditional software development process, the CI/CD process happens in stages.
It evolves from building and testing code to deployment in four phases as follows:
Stage 1: Source
When a developer creates a pull request or pushes a commit to the repository, the CI/CD pipeline is triggered to begin compiling the source code and build the software program. This means you’ll have a server or use a cloud service to act as the compiler.
Stage 2: Build
As multiple developers work on the software project at the same time, the source code they write is continuously tested and merged. This ensures the code is always ready for delivery.
Stage 3: Testing
The new changes undergo a series of automated tests to ensure the source code is correct and the software is behaving as it should.
Stage 4: Deployment
The final stage is the deployment stage. If the set of changes are successfully integrated and pass all the tests set in place, the changes are ready to go live.
The deployment can happen manually after the person in charge has reviewed the new features or it can happen automatically.
Once the changes go live, the end users have a chance to experience the functionalities and provide feedback.
If there are bugs or improvements needed, the source, build, test, and deployment cycle repeats itself.
Popular CI/CD Tools
After mapping the software development process into stages, the next step is to acquire the right tools for each stage in the pipeline.
As CI/CD is a popular and fast growing practice in organizations, there are quite a number of open source tools dedicated to ensuring a successful implementation of continuous integration and continuous delivery/deployment practices.
Here are some of the best tools for continuous integration and continuous delivery:
Azure’s DevOps Service
Azure DevOps is an all in one Software as a service (SaaS) platform offered by Microsoft. It provides developers with a platform to develop, test, and deploy applications using the CI/CD framework.
The beauty of the Azure DevOps service is it’s versatility. It offers multiple tools in one platform and works with any platform, programming language, and cloud environment.
GitHub is the most popular hosting service for Git repositories. It makes it so much easier for developers to collaborate.
Developers can download the shared repository onto their own computer, make pull requests and push changes to the shared repository.
Jenkins is probably the most widely used CI/CD tool all over the world. In fact, it played a major role in popularizing the DevOps movement.
So why is it this popular? It’s robust yet free to use (open source), multi-platform, functions as both a CI and CD tool, and can build and test code multiple times in a day.
Docker is also a popular CD tool for deploying container-based projects.
Bamboo is a CI build server that can handle virtually everything in the process: automatic builds, merges of branches, tests, and releases.
Furthermore, it can run multiple batch tests in parallel and integrate with other CI/CD tools like Bitbucket and JIRA.
CirceCi is a testing tool that reduces bugs and improves the quality of software. The best thing about it is its flexibility.
Robust yet simple to use even for beginners without much experience in coding or DevOps practices, Katalon Studio is one of the best CI/CD tools for test automation.
Another reason for its wide appeal is that it’s compatible with a wide range of platforms, operating systems, and popular CI/CD tools.
Who Uses The CI/CD Pipeline?
It takes the right tools, practices, and people to implement the CI/CD framework successfully.
Now that we’ve looked at the practices that are automated and the popular tools for every stage in the process, let’s talk about the people involved.
Being a DevOps practice, CI/CD is both a development and operations tool. It’s used by DevOps engineers, IT professionals, developers, testers, and analysts.
DevOps engineers are responsible for setting up the CI/CD pipelines, software developers commit the code, while the operations department comes in after the code is deployed and the application delivered to end users.
Where to Get Started Learning CI/CD
Here are the recommended resources to learn more about CI/CD and how to successfully implement the practices in an organization.
Best CI/CD Courses for Beginners
DevOps, CI/CD (Continuous Integration/Delivery for Beginners
The CI CD & DevOps course is the best course if you want to gain a deeper understanding of continuous integration, continuous delivery, DevOps, and pipeline. John Honai does an outstanding job explaining these concepts in an easy to understand manner.
Also learn how these practices evolved in order to solve the pain points in the conventional software delivery process. The use of bullet points, animations, and cartoons make learning feel like fun.
The CI/CD Process Continuous Delivery & DevOps
Developed at the University of Virginia, the Continuous Delivery & DevOps course is one of the best CI/CD courses for anyone new to the concepts.
It does a fantastic job of explaining the basic concepts including DevOps, continuous testing, and continuous delivery.
Once you understand the basics, it will equip you with the knowledge and skillset required to successfully implement a continuous deployment pipeline in any organization.
Best CI/CD Books for Beginners
Continuous Delivery: Reliable Software Releases through Build, Test, and Deployment Automation (Addison-Wesley Signature Series (Fowler))
The Continuous Delivery book uses clear and concise language and practical examples to explain and describe continuous delivery concepts.
It also explains how to build a deployment pipeline by automating the processes of building, integrating, testing, and deploying software.
Continuous Delivery with Docker and Jenkins: Create secure applications by building complete CI/CD pipelines, 2nd Edition
Continuous Delivery with Docker and Jenkins focuses on implementation. It will guide you through building a complete continuous integration and delivery pipeline using tools such as Jenkins, Docker, GitHub, and Ansible.
Also learn how to use Jenkins and Docker together to make the most of the CI and CD processes. You will also learn how to apply Jenkins on the cloud.
To Wrap Up
The CI/CD pipeline brings a host of benefits to organizations. It ensures speedy delivery of high quality applications to end users, promotes developer happiness, can and improves the bottom line.
As more and more organizations embrace modern software development practices such as DevOps, continuous integration and delivery are quickly becoming best practices in software development and deployment.
Adding DevOps and CI/CD skills to your resume will set you up for a successful software developer career.
Mike is the creator of Go With Code and a coder at heart 🙂