What is the difference between Continuous Integration (CI), Continuous Deployment (CD) and Continuous Delivery (CD)?

DevOps 4 min read
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Continuous Integration (CI) Vs. Continuous Deployment (CD) Vs. Continuous Delivery (CD)

When we talk about modern software compilation and distribution processes, we often hear abbreviations such as CI and CD. Here we will describe to you the differences between them.

CONTINUOUS INTEGRATION

In a continuous integration environment, developers will frequently submit code to the trunk. These new commits need to be verified by compiling and automating the test flow before they are finally merged into the mainline.

This is based on the importance of automated test verification during the continuous integration process to ensure that all submissions are quality ensured after the mainline is merged – some issues may arise during the process.

CONTINUOUS DELIVERY

Continuous delivery is the process of publishing our application. This process ensures that we deliver as quickly as possible. This means that in addition to automated testing, we also need to have an automated publishing stream, and the application can be deployed online anytime, anywhere with a single button press.

With continuous delivery, you can decide to publish every day, every week, every two weeks, which can be set up according to your business.

However, if you really want to experience the benefits of continuous delivery, you need to publish in small batches and deploy to the production line as soon as possible to facilitate troubleshooting in the event of a problem.

CONTINUOUS DEPLOYMENT

If we want to go one step further, we will continue to deploy. In this way, any modifications that pass through all existing workflows will directly meet the customer. There is no human intervention (no one-click deployment button), and only when a modification fails to build in the workflow can it prevent it from being deployed to the product line.

Continuous deployment is a great way to speed up the feedback loop with your customers, but it puts pressure on the team because there are no more “release days”.

Developers can focus on building software, and they see their changes go live a few minutes after they finish their work. Basically, when a developer merges a commit in the main branch, the branch is built, tested, and deployed to the production environment if all goes well.

Integration of CI CD and CD

Of course, each part is closer to the production environment. You can build your own continuous integration environment, and then, once the team adapts, you can add a continuous delivery flow – finally, you can add a continuous deployment flow to the entire workflow.

Continuous Delivery consists of automating building, testing, and deploying changes to a software code or UI. Find out everything you need to know about it with our DevOps Consultants.

The Continuous Delivery in DevOps is a practice of developing, testing and delivering improvements to the software code or user environments using automated tools. Development teams produce and test the code in short cycles.

In this way, the code is always in a deployable state. So, even if the software version being developed needs to be deployed suddenly, this is not a problem with this approach.

The goal is also to shorten the feedback loop to improve the quality of the software. The code is regularly issued to the test environment (UAT) which makes the causes and effects observable. All code features can be tested, helping to reduce unexpected performance issues once in production.

How does it work?

Continuous Delivery follows a process called “Continuous Delivery Pipeline”. This pipeline begins when the developer adds his code to the source directory. A series of automated tests is then launched to ensure the quality of the code.

Once the code is verified, the executables are automatically deployed in an intermediate environment such as the “staging” environment or the UAT. The code is ready to go into production, and can be delivered on request.

Main elements 

The proper functioning of the Continuous Delivery is based on three fundamental principles: Continuous Integration, Configuration Management, and Test-Driven Development.

The continuous integration or Continuous Integration ensures that the code on which multiple developers work scattered in many places still to be integrated within a common directory. This avoids conflicts between code commits.

The configuration management allows for its abstraction from the complexities of a product in simple configurations. This makes the software flexible, scalable and lightweight.

Finally, “test-driven” development is the essence of Continuous Delivery. It ensures that the code is tested and deployed in minutes. Previously, deployments ranged from weeks to months in multiple releases.

What are the benefits?

Although it requires an initial investment to implement infrastructure and testing, the benefits of Continuous Delivery are multiple.

First of all, this approach allows for better quality of products. Automated testing tools can improve security, performance, and code integration.

In addition, releases are faster and less risky. Manual pre-production deployment processes are eliminated by automating build and deploy. In fact, production releases no longer hold unpleasant surprises and are no longer moments of panic.

As new features are delivered faster and more reliably, it also enables increased customer satisfaction. Downtime during release can also be minimized, and development teams can receive constant feedback from customers to better understand and respond to their needs.

Continuous Delivery vs. Continuous Integration vs. Continuous Deployment: What’s the difference?

Continuous Delivery should not be confused with Continuous Integration and Continuous Deployment. These are different concepts, which represent the three stages of maturity evolution in development practices.

Continuous Integration is the first step, and refers to individual code integration in the overall development environment after building and testing. Tools like Jenkins help ensure that code is compiled, run and tested before being integrated.

Continuous Delivery is the second step, and can only work if continuous integration is already in place. It involves regression, UI, and performance testing to ensure that the code is ready for production.

Finally, Continuous Deployment goes even further by automating the deployment of code in production after each commit code and build. Thus, the deployment is no longer on demand, as is the case with continuous delivery, but fully automated.

Take away

As mentioned earlier, you can adopt continuous integration, continuous delivery, and continuous deployment. What you do depends on your needs and your business situation. If you’ve just started a project and don’t have a customer yet, then you can create these workflows, preferably by implementing all three aspects and iterating over both your project iterations and demand growth. If you already have a production project, you can implement them step by step in stages yourself or with the assistance of an expert DevOps Consultant.

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