1.     CI/CD: Continuous Integration (CI) and Continuous Delivery (CD)

CI ve CD stand for Continuous Integration and Continuous Delivery/Continuous Deployment. Simply put, CI is a modern software development practice where incremental code changes are made frequently and reliably. The automated build and test steps triggered by CI ensure that the code changes merged into the repository are reliable. The code is then delivered quickly and smoothly as part of the CD process. In the software world, CI/CD refers to the automation that allows code changes to be delivered quickly and reliably from the developer’s computer to production.

Importance of CI/CD

CI/CD enables organizations to send software quickly and efficiently. It facilitates the process of bringing products to market faster, continuously deploying code into production, and ensuring a steady flow of new features and bug fixes through the most efficient delivery method.

1.1. Continuous Integration (CI)

Continuous integration is the practice used to ensure that the system remains functional after changes to the code, detecting if the changes cause any issues. Unit tests are used to identify problems and failures.

Since the changes are part of a new build, any errors in the tests indicate that the changes have broken the system. In this case, all programmers are notified so that the error can be fixed as soon as possible. With continuous integration, a working version is always created as a result of the code changes made by the programmers.

Continuous integration (CI) helps developers integrate code changes more frequently. When the changes made by developers are merged in an application, the application needs to be automatically compiled and validated through various levels of testing to ensure that these changes don’t break the application.

1.2. Continuous Delivery (CD)?

Continuous delivery is an extension of continuous integration. It is the automated path to deploy a successful build into an environment (test or live environment). There is a small difference between delivery and deployment. Delivery is done manually, while deployment is automated.

When continuous delivery is applied properly, customers will have access to a build that has gone through a standardized testing process.

1.3. CI/CD Principles

The principles for successful production deployments in CI/CD include:

• Design your system to support recurring releases.
• Implement metrics that help detect problems in real-time.
• Always develop code with a test-focused approach.
• Work with small iterations.

The autonomous engineering (automation) team should be responsible for the software’s quality and stable progress.

To fully implement CI/CD, you must automate everything.

Benefits of CI/CD

• Increased Efficiency: Automated deployment and testing processes improve efficiency and lighten the workload for engineering teams.
• Reduced Risk: CI/CD reduces the risk of configuration errors by ensuring the code is updated continuously. Incremental updates help manage risks with small improvements rather than large updates.
• Service Agility: CI/CD shortens delivery times and enables faster feature release. It supports the ability to increase the diversity of new services and allows for quicker feedback to customers.

Best CI/CD Tools

There are several CI/CD tools in the software development world. These tools are chosen based on budget and project requirements. Here are some of the most popular CI/CD tools:

• Jenkins:

An open-source CI/CD tool that facilitates continuous delivery and also offers continuous integration. It also provides real-time testing and reporting capabilities. Due to its open-source nature and long-standing presence, it is one of the most commonly used and best CI/CD tools.

• TeamCity:

A server-based CI/CD tool used for Java, developed by JetBrains. It can be installed on Windows and Linux servers. TeamCity offers an easy option for small teams to integrate with Azure DevOps and Jira Software Cloud.

• GitLab CI:

A tool built into GitLab. To use GitLab CI/CD, the codebase must be hosted in a Git repository, and scripts that need to be present in the root directory must be specified.

• CircleCI:

One of the best CI/CD tools for open-source projects and large-scale projects. It supports languages on Windows, Linux, and macOS platforms.

Authors:

Gulselin GULER KORKMAZ

Zehra TURHAN

Betul ABACI

Busra SACAKLI

Bengunur GULTEKIN

Ahsen KAS