Continuous Integration (CI) has been around for over three decades. Yet, CI systems came to be only about ten years ago. Since then, CI has had a huge positive impact on the development process. Moreover, many tools have risen to put it into practice. This article will cover Continuous Integration's definition. Plus, we'll see how it works and why it's essential. We'll also discuss its benefits, challenges, and best practices. We'll share some of the most popular Continuous Integration tools to round things off. Are you ready for efficient dev processes?
What is Continuous Integration (CI)?
Continuous Integration is a DevOps practice. Here, code changes from many developers or contributors integrate automatically. These code changes merge into a central repository. Later, it runs automated builds and tests. CI makes it easy for developers to work on different features simultaneously. Also, it helps improve bug-finding, software quality, and validation and updating times.
Continuous Integration vs. Continuous Delivery vs. Continuous Deployment
As mentioned, CI deals with code changes and merges them with a central branch. Meanwhile, Continuous Deployment (CD) goes one step further. It releases the modifications successfully made through the pipeline to customers or users. Continuous Integration mainly benefits developers. In contrast, CD benefits business users. These get a product or update as soon as it passes the quality assurance step. Finally, Continuous Delivery (also called “CD”) automates the whole software release process. It includes Continuous Integration and makes every change to the code a deliverable. Most of the process is automated, but the “deploy to production” step is manual.
Continuous Integration Testing
CI Testing is, in simple terms, the practice of testing at the time of every code integration. Some consider Continuous Integration testing a prerequisite for both CI and CD. This testing is at the core of CI quality assurance as it guarantees bugs are easily found and fixed. There are different types of CI testing. Some examples of it include Unit Testing, Code Quality Testing, Integration Testing, and Security Testing.
How does Continuous Integration (CI) work?
With Continuous Integration, all software code gets stored in a shared repository. Devs check out the code they want to work with on their private terminals or workstations. After working with that code, they commit it to that shared repository. Also, there's an automated server building the system and running integration tests. This procedure ensures everything works. If there are issues with the build, the server will state where the code failed so the development team can fix it.
Why is Continuous Integration important?
Before CI, devs would merge their changes in the main code after completing the work. As a result, code-merging turned complicated and time-consuming. Plus, it enclosed integration conflicts and bug accumulation. Thus, these problems arose at the end of the projects. Continuous Integration makes the development process faster and less risky. You can see all its benefits below. We all know there is no such thing as a perfect tool or method, so we’ll also add a couple of challenges for good measure.
Benefits of Continuous Integration (CI)
1. Delivery. Increased productivity and automation lead to saving time in the development process. Thus, the time between development, integration, and testing reduces. As a result, the final product will take less time to deliver.
2. Productivity. Automating prior manual tasks means devs have more time to focus on complex issues. Moreover, working with decreased bug risk means teams work confidently, improving productivity.
3. Bugs Fixing. With regular and often testing, teams can easily find and address bugs early. So you can avoid larger and more complex problems down the line.
4. Visibility. A shared repository entails transparency throughout the development process. This approach eases complete visibility for everyone working on the project. Also, it improves team communication.
5. Quality. Given the continuous review and testing of new code, final products aim for higher quality.
6. Risk Reduction. Dealing with bugs and code defects faster facilitates risk mitigation in real time.
Challenges of Continuous Integration (CI)
1. Organization. Implementing Continuous Integration entails changing the organizational culture. This procedure is a challenging feat and can be time-consuming. Staff will need to retrain, and existing operations will need to change. The changes we just mentioned also come with a financial cost. The tools and training needed to install CI may be more than your company can afford. It is worth noting that this is a sound investment that will give you a great return in the long term.
2. Demands. Continuous Integration requires building a testing suite and several test cases. Here, developers don’t spend time writing the code for the product. So, it can sometimes be discouraging for team members. Also, CI doesn’t eradicate manual testing; thus, daily testing can be cumbersome for some teams.
Continuous Integration (CI) Best Practices
You will find different versions of Continuous Integration best practices depending on where you look. Here are some of the most relevant ones.
● Test-Driven Development. The first step is to tackle automated testing in the CD pipeline. Later, expanding and improving test coverage is vital. Here, Test-Driven Development (TDD) can go a long way. TDD means you write tests before you start coding, which leads to simpler, bug-free code.
● Commit Early and Often. It would help if you strived to commit your code changes daily. This system avoids long merge times. Also, it allows a quicker code deployment. Daily commits may seem bothersome if your team handles long-running branches. Likewise, some developers may fear the potential scrutiny. But here, the benefits outweigh the potential downsides. And these can also be offset by fostering a culture of collaboration.
● Test Each Every Time You Commit. Running automated tests whenever you commit changes to a shared repository means devs get instant feedback. This way, the code is always in a releasable state.
● Optimize Pipeline Speed. A faster CI pipeline translates into a speedier product feedback loop. You can measure and monitor your pipeline and optimize its stages. It would be best if you made things as simple as possible so you can quickly identify and fix failures.
● Learn From Your Mistakes! Every time an automated integration test fails, look into what caused it (instead of who). This approach leads to better code and better work culture. Lean on learning instead of blaming!
Popular Continuous Integration (CI) Tools
With all the context, here are some of the market's most sought-after CI tools.
Jenkins is one of the most popular automation tools available. The free and open-source automation server launched in 2011 and is still strong. Based on Java, it supports Windows, Linux, Mac, and Unix machines. The CI server is highly customizable, helps bolster scalability, and is easy to install and set up. It also has a unique plugin ecosystem and can distribute work among many machines.
This Continuous Integration platform was also released in 2011 and is quite popular. CircleCI is highly flexible and focuses on performance. Also, it has an intuitive and customizable interface. Its features include scaling up to 80x concurrency and parallel task execution. Furthermore, it supports a matrix of version control systems. CircleCI offers a free cloud-based version and paid cloud and self-hosted ones. CircleCI’s pricing starts at $15 per month.
JetBrains developed TeamCity in 2006. The company is also responsible for IntelliJ and other popular dev tools. This CI/CD solution offers real-time reporting, test intelligence, and parallel execution. It's easy to install and set up, including build configuration template extraction. Plus, it supports all programming languages. TeamCity offers free and paid enterprise licenses (for $1,999 for the first year.)
4. Travis CI
This SaaS platform was initially designed for open-source projects and written in Ruby. Travis CI currently supports over 30 languages and various platforms. Also, it offers parallel testing and includes GitHub and Bitbucket synchronization. This tool has a 30-day free trial. After that, you can choose the Core plan for $69/month and the Enterprise plan with flexible pricing. Travis CI includes many pre-installed databases and services. Further, it offers auto-deployments on passing builds.
This DevOps platform has built-in support for both CI and CD processes. GitLab is user-friendly, developer-centric, and enterprise-ready. The tool includes load performance and continuous security testing, among many other features. The GitLab CI/CD tool is free with an existing GitLab paid plan. You can choose between the Premium plan for $19 per user per month and the Ultimate plan for $99 per user per month. Are you planning on using GitLab or already using it for your projects? It's a great option for implementing Continuous Integration!
It's easy to see why companies worldwide regard Continuous Integration well. We hope this article has given you all the reasons and tools you need to implement your CI pipeline!