CI/CD Explained with Examples – Continuous Integration & Continuous Delivery

Editorial Team

Continuous Integration & Continuous Delivery Explained

As DevOps teams work on software and applications, they should ensure that code changes are implemented and delivered regularly and through the best means possible. They, therefore, observe several practices to ensure that their output is effective and reliable.

This is where CI/CD falls. It is more of a culture filled with practices and operating principles that allow application development teams to execute code changes properly. It has over time proven to be effective, explaining why teams are advised to use it.

It is also worth mentioning that this is an agile methodology best practice. It ensures that DevOps teams focus their energies on meeting the business requirements while upholding high code quality and security standards through automation.

In this article, we take an in-depth look at this practice to answer some of the questions you may have had, given that it is pretty common. But first, let us start by defining what CI/CD pipeline is.

What Is C1/CD Pipeline?

A CI/CD pipeline encompasses all the steps undertaken to ensure the delivery of a new software version. Whenever an organization practices continuous Integration and delivery, one can say that it has established a CI/CD pipeline. It relies on monitoring and automation to ensure that the application development workflow is improved, especially at the Integration and testing phases, which are the key.

Can an organization manually execute all the steps in the CI/CD pipeline? Yes. However, note that CI/CD pipelines can only be truly successful when the application lifecycle is automated.

You will see the role that automation plays as we go on with our discussions. Let us now dissect these two concepts independently.

Continuous Integration

Continuous Integration, shortened as CI, is a development practice that follows several principles to help development teams regularly check in their codes to version control repositories and implement minor changes. It requires that every team member integrates his/ her work with those produced by others continuously.

Each Integration is then verified through an automated build and series of tests.  It is a crucial development practice and mechanism which team members use to integrate and validate changes, given that they use different platforms and tools. Thus, it serves a technical goal: to offer a consistent and automated means of building, packaging, and testing applications.

Consistency plays a significant role in the integration process as it ensures that the teams make code changes more frequently, which drives collaboration and ensures high software quality. Regular integrations also ensure that these teams can detect errors quickly and locate them easily.

Note that the changes introduced in most cases are small. CI, therefore, makes it possible to quickly identify the changes that brought about a defect, aiding in its faster correction since it requires developers to integrate code several times in a day.

Benefits of Continuous Integration

Just like other Agile methodologies and practices, your organization stands to benefit a lot from continuous Integration. Before we look into these, it is worth mentioning that perhaps the most significant benefit of this development practice is quick problem-solving.

Continuous Integration requires you to integrate frequently, lessening backtracking cases to discover where things went wrong. This gives you more time to focus on more critical issues, such as your application’s features.

Also, note that this is a cheap and timely approach to coding. You will witness more extended periods between integrations in its absence, giving you a harder time finding and fixing problems. Other advantages that your organization stands to achieve are:

  • It saves you from long and tense integrations, thus saving you time and allowing you to channel your efforts to other areas.
  • It helps you build a solid foundation.
  • It informs you beforehand whether your code will work or not, saving you from making a gamble, which may be costly in the end.
  • It helps you identify issues during the early stages of development, saving you from a waste of efforts or unnecessary backtracks.
  • This practice slashes off your integration problems, making it easier to sustain rapid delivery of software.
  • It saves you time that you would have otherwise spent in debugging and adding features to your software.

These are just, but a few advantages teams that observe continuous Integration get to enjoy. However, as we mentioned, this agile methodology is backed by several principles and practices. Let us take a look at these:

Continuous Integration Best Practices

  • Maintaining a single repository, which is perhaps the most important practice.
  • Automating deployment of the application.
  • Allowing everyone to access the latest executable version by making the process easy.
  • Ensuring that the build is fast.
  • Testing the application or different stages in a clone of the production environment.
  • Encouraging openness by ensuring that everyone can see what is happening.
  • Ensuring that every commit builds on an integration machine.

How is Continuous Integration Done?

Now that you understand what this is, the benefits, and some of the practices, it is only fair that we focus on how your team can successfully execute it. Keep in mind that this is an agile technique, and therefore, the entire team must be involved. Here is how continuous Integration is done:

  1. The developers involved in building the application check out the codes into their private workspaces.
  2. Once they are done, they commit the changes to the repository.
  3. The continuous integration server monitors the repository while checking out the occurring changes.
  4. The continuous integration server builds the system before running unit and integration tests.
  5. The server then releases all the deployable artifacts for testing.
  6. The server will then assign a build label to the given version of code that it has just built before informing the team of the success.

However, one major question arises from this illustration: what happens when the build or tests fail? Simple. The team will fix the issue at the earliest opportunity and continue integrating and testing as the project continues. I hope that you now understand what we mean by this process preventing cases of backtracking.

Also, note that it imposes on the team several responsibilities. The team must check in frequently. They should refrain from checking in broken and untested codes and refrain from checking in when the build is broken. The team must also stay after check-in and wait for the system to build.

However, teams are also allowed to develop ways of doing things, given that this is an Agile methodology. Therefore, instead of waiting for commands from the boss, they can effectively manage themselves, provided that the policies and practices of continuous Integration are upheld.

Continuous Integration Example

Here is where we bring you close to what CI is. On simple example of continuous integration is having a single repository for all your application code. This means that you get to run a few changes on th repository when you need to change something instead of backtracking the entire process.

Continuous Delivery

This is more of a sequel of continuous Integration. It builds from where continuous integration leaves, ensuring that the delivery of applications to the select infrastructure environment is automated. Teams also work with several environments, such as development and testing, just like they use different platforms and tools.

Like continuous application, this is also a development practice. It ensures that the code changes are automatically prepped to be released to production. It deploys all code changes to a testing or production environment once the build stage is over.

This practice has to be correctly implemented as it ensures that developers get a deployment-ready build artifact that has gone through a standardized test process successfully. They get to go beyond unit tests by verifying the application updates before finally deploying them to the consumers.

Some of the tests involved here are load testing, UI testing, API reliability testing, integration testing, among many others. It, therefore, happens after continuous delivery has been done to give developers time to validate the updates and uncover final issues before the application is brought to the end users get to interact with the application.

Difference Between Continuous Delivery and Continuous Deployment

We must have mentioned deployment while explaining what continuous delivery is. Continuous delivery and deployment are often confused, given that they come at the tail end of development. They are pretty different.

In continuous development, production automatically happens without a need for approval. However, for continuous deployment, there has to be a manual approval. Let us shed more light on this:

The whole software release process is automated for continuous delivery, meaning that every revision committed brings about a computerized flow. In contrast, the decision to deploy a live production environment wholly rests on the developer.

Continuous Delivery Best Practices

Like continuous integration, continuous delivery has its guiding practices that promote an automated deployment pipeline. These are:

  1. Ensuring a repeatable, reliable process through the same release in all environments.
  2. Automating everything, including the build, testing, releases, and any configuration changes.
  3. Upholding version control of the code, configuration, scripts, documentation, and databases.
  4. Dealing with the time-consuming and challenging things first.
  5. Dealing with bugs as soon as they are created to ensure high build-in quality.
  6. Extending responsibility all through the production, which ensures that everyone is involved.
  7. Continuous improvement, which is arguably the most important practice when it comes to this development approach. Development should b guided by a culture seeking continuous improvement. 

Benefits of Continuous Delivery

Continuous delivery brings with it several benefits that you and your team should get to experience. Here are some:

  1. It Improves Developer Productivity

Thanks to the practices that we have covered above, your team will be more productive since CD eradicates manual tasks, thus reducing the number of errors and bugs that your customers experience.

  • Helps Teams Locate and Fix Bugs Quicker

This is arguably one of the main benefits of this process. It allows development teams to frequently locate and address bugs while still in the early stages of development, thanks to comprehensive testing. This practice ensures that you can perform as many automated tests on your code as possible and fix issues before deployment is done.

  • It Is Automated

Continuous delivery ensures that your team will enjoy an automated software release process. They will automatically build, test, and work on the code changes and redefine your software delivery process by making it more efficient and effective.

  • Faster Update Delivery

Remember, the main reason for development is to satisfy the customers, who are often the end-users. Luckily, continuous development ensures that your team offers faster and frequent updates to customers. If done properly, the end product will be ready for deployment since it passes through a series of standardized test processes.

CD, therefore, makes sure that there is a means of delivering code changes to the different environments.

Continuous Delivery Examples

It may be quite difficult to pinpoint at a given continuous delivery example. However, it is important to note that this practice comes about in the different tests beyond the unit tests. These include load testing, UI testing, integration testing and API reliability testing.

Difference Between Continuous Integration and Delivery

Together, these two tools play an essential role in the storage of the parameters that should be packaged with every delivery. Since it is an automated pipeline, the DevOps teams should not worry about the necessary service calls to web servers, databases, and any other service that may need restarting as CI/ CD automation takes care of that. The same also applies to any additional procedures that may be necessary when applications get deployed.

Also, note that these two tools require continuous testing since they are meant to provide quality applications and code to the DevOps teams and general users. This is generally done through several automated regression, performance, and several tests.

However, that does not change the fact that they are different. Here is the difference: Automation. Continuous Integration calls for a manual push to production, whereas it is automated in continuous delivery.

Conclusion

We have covered most of the things that you should know about Continuous Integration and Delivery. These are methodologies that should be put in place to ensure that your team comes up with the best software versions.

However, note that these two are not similar, and therefore, you may need to check with our article before you think of implementation.