What is CI/CD?- Detailed Guide

The Continuous Integration (CI) and Continuous Delivery (CD) pipelines are an ecosystem of automated procedures that let teams of developers integrate modifications to code, securely deploy those changes to production.

This post will go over the fundamentals of continuous integration and continuous delivery pipelines and why you should use them. The next step is to look at the pipeline as its whole, including each stage, the components of an effective pipeline, and more.

What is Continuous Integration?

Conventional software development practices involved numerous developers working independently on separate sections of code until the very end of the release cycle, when all of their contributions were finally integrated. After extensive testing, we are able to identify and fix the numerous flaws and difficulties that this introduced. Release of the software could only occur after this. As a result, teams would often deliver new versions of the program only once or twice a year, and the software's quality would consequently decrease.

The goal of continuous integration (CI) is to address this issue and enable agile development processes. With continuous integration, developers can be certain that their code changes will be instantly reflected in the master branch of their software project. Continuous integration (CI) systems automate test runs, which helps engineers obtain quick feedback and fix bugs instantly. Until a feature is integrated with other code modifications and is working on the main branch, it is not considered done.

In order to achieve continuous integration (CI), organizations generally deploy a build server. This server can then read changes to the code, run automated tests using a combination of tools, merge the changes into the main branch, and generate new software artifacts.

Software development velocity and quality were both boosted significantly by CI. Teams have the ability to provide more user-valued features, and many companies release software weekly, daily, or even several times daily.

What Is Continuous Delivery?

In the past, releasing new software was a huge, complicated, and potentially risky process. Operations teams were responsible for releasing new releases to production after they had been tested. There were checklists and manual processes needed, and it may take hours, days, or weeks, depending on the software's scale. Specialized experience was also necessary. There were a lot of failed deployments that needed developers to provide rapid help or find solutions.
Numerous difficulties were brought about by this conventional method. It caused teams a lot of stress, cost the company a lot of money, and put the organization in danger, all while introducing new problems and failures into production settings.

One approach that seeks to automate these challenges is continuous delivery (CD). A continuous delivery (CD) strategy prioritizes rapid software packaging and production deployment. A fundamental tenet of continuous delivery is the elimination of manual intervention required to deploy software modifications to production.

The CD system packages the newly created system after the CI system incorporates new modifications, deploys it to a testing environment, and automatically evaluates its operation before pushing it to production. A human can approve this final step, although it shouldn't take much work.

Complete automation of the software development lifecycle—from coding to tests to system setup to software deployment—is necessary for CD implementation. There needs to be an automated system for creating and modifying environments, and all artifacts should be stored in a repository for source control.

True continuous delivery (CD) pipelines are advantageous because they facilitate an agile development process and enable development teams to provide value to clients instantly.

What Is a CI/CD Pipeline?

Continuous Integration/Continuous Delivery (CI/CD) pipelines are frameworks that help agile DevOps teams focus on delivering code reliably and iteratively. Continuous integration, testing, and delivery are all part of the workflow. Continuous deployment and delivery are also part of the workflow. In order to create high-quality software, the pipeline organizes different methods into a coherent procedure.

A continuous integration and continuous delivery (CI/CD) pipeline relies on test and build automation to support developers in finding any code errors at an early stage of the software development lifecycle (SDLC). Then, releasing the software to production and pushing code updates to different environments becomes much easier. Application performance and security are two critical areas that automated tests can evaluate.

Autonomy is helpful in every step of a continuous integration and continuous delivery pipeline, not only testing and quality control. Safer and dependable software can be built and released more quickly with its support.

A Brief Overview: CI/CD Procedure

If your company wants to deploy code rapidly and on a large scale, you must understand the CI/CD process. Every step of the process, from submitting code to testing, building, deploying, and producing, is covered by the CI/CD pipeline workflow. Incorporating CI/CD best practices in each phase ensures smooth and error-free deployments.

To see how the process works in action, look at a CI/CD workflow sample. An example of a development team working on a web application is what we're going to discuss here.

• By consistently pushing their code improvements to a shared repository, developers in this example foster cooperation and keep everyone up-to-date with the latest code. When modifications are made to the code, the CI/CD pipeline is started.
• The submission of the code triggers a chain reaction of automatic actions. The first step is to use a static code analysis tool to look for bugs and security holes in the code. The following step of the build process is to generate the application's executable or package files through compilation.
• Automated tests are run after the build to ensure the code is accurate. Regression analysis, stress testing, and integration testing are all part of this suite of tests. The developers are promptly notified of any flaws or defects, and they promptly address them.
• The code moves on to the deployment phase after testing is completed. Prior to being transferred to the production environment, it is initially launched to a staging or beta environment for additional validation.
• Tools such as GitHub, Jenkins, and Selenium are utilized to automate and manage each step of the continuous integration and continuous delivery (CI/CD) process. This explains how a CI/CD pipeline, when properly set up, lets programmers provide high-quality code rapidly while reducing the likelihood of mistakes. In software development, it stresses the significance of automation, teamwork, and incremental improvements.

Components of a CI/CD Pipeline

The development workflow and the lifecycle of the CI/CD pipelines are comprised of these steps, beginning with the authoring of the source code and concluding in production. You can run a pipeline automatically whenever there's a change in the code, or you can plan it to run at a certain time, or you can execute it after another pipeline has finished running.

The CI/CD pipeline consists of four components:

1. Commit Change

Whenever a developer makes a modification to the code, they should save it to a version control system like Git. The CI/CD pipeline is started at this stage. Proper tracking and versioning of code modifications is ensured by committing them.

2. Trigger Build

When a new commit is detected, the build process is automatically triggered by the version control system. New modifications are regularly merged and tested thanks to the automated build process triggering.

3. Build

Coding takes place throughout the build stage. A team of people, or perhaps more than one team, working together on a larger project will usually accomplish this. A version control system (VCS) stores code, and a Git-based workflow, often called GitOps, is often used to manage the addition of code to the repository. Tools that control and standardize developer environments are very helpful in a pipeline for removing code discrepancies between authors. For cloud-native apps, this typically means utilizing a Docker container.

4. Notify of Build Outcome

The team is informed of the build results—passed or failed—by the CI/CD system. Developers are able to swiftly detect and fix build issues when they receive immediate feedback on the build state. Jenkins and GitLab CI dashboards, email, and chat connections (such as Slack and Microsoft Teams) are all examples of notification systems.

5. Run Tests

Building artifacts undergo automated testing. All kinds of testing, such as unit tests, integration tests, and end-to-end tests, are possible. Testing frameworks like JUnit, Selenium, TestNG, pytest, etc. By executing tests, we can guarantee that the updated code is bug-free, up-to-date, and of sufficient quality.

Code testing increases trust that the code will function as intended in the face of increased demands for durability and the introduction of more diverse infrastructure. It is possible to automate the testing of your code. Typically, doing this manually is a difficult, repetitive, and somewhat boring procedure. The advantages of thoroughly testing code before delivery and deployment can be substantial, leading to a high-quality result; nonetheless, many teams fail to adequately utilize or even skip the test stage.

Since there are many subsets of testing, the best approach to get maximum code coverage and quality is to employ a mix of these with a variety of tools.

To decrease the pipeline run time, it is possible to parallelize the tests that are utilized frequently. Such as:

• Smoke testing entails doing brief logic checks on the program.
• All of the code or the entire system can be tested via integration tests. They make sure that the new code doesn't interfere with the old code.
• The purpose of unit testing is to verify the correct operation of a single function, a group of related functions, or even a specific section of code. It is possible to perform tests in parallel and isolate smaller portions of the infrastructure in order to reduce the feedback cycle.
• To make sure the configuration adheres to the project policies you've specified, you should do compliance testing.
• Before releasing to production, make sure everything is fully functional with end-to-end testing (E2E). This is the last and final step in the process.

6. Notify of Test Outcome

A report is sent back to the development team with the test suite's results. The ability to receive immediate feedback on test results is crucial for developers to quickly fix any issues. It is possible to send results by email, chat, or dashboards in the same way as building notifications.

7. Deliver Build to Staging

The build artifact is moved to a staging environment if the tests are passed. Final review before the production launch is possible in the staging environment, which simulates the operational environment. Deployment solutions tailored to the cloud, such as AWS CodeDeploy, or general-purpose technologies like Ansible, Chef, Puppet, or Kubernetes.

8. Deploy to Production

The build is either moved to the production environment automatically or manually after it has been verified in staging. At this point, end-users will have access to the updated features and bug fixes. To lessen the likelihood of downtime and risks, deployment tactics could involve blue-green deployment, canary releases, or rolling upgrades.

Advantages of the CI/CD Pipeline

Among the several advantages that can be gained by implementing CI/CD pipelines are:

• Cut Expenses: Less time spent coding and deploying the app or infrastructure equals less time spent using human resources.
• Time to Deployment Cut in Half: Automating repetitive tasks shortens the deployment time. An efficient and shorter overall process duration is achieved by streamlining the complete process, beginning with development and ending with deployment. The frequency of deployments can be increased. A substantial competitive advantage can be gained by companies through the rate of release. In the event that an issue arises, it is very simple to roll back deployments. Code developers won't have to divert their attention.
• Making Feedback Possible in Real Time: Helps teams incorporate user comments into code and process improvements. The testing phase finds errors and provides instant feedback to help fix the code. It is easier and faster to rectify faults if they are found earlier in the coding process. Team members can be notified of success or failure at each level through the use of configurable notifications.
• Strengthening Teamwork: Problems are visible, feedback is viewable, and modifications can be made as needed by the team.
• Audit Trails: Logs are generated at each level of the process, which can help with accountability and traceability.

What Are the Challenges of CI/CD Pipelines?

• Limitations of the Environment
  When testing code changes, development and testing teams sometimes share environments or work with constrained resources. It can be difficult for CD workflows to share environments. Several teams can simultaneously commit code to a single environment in big projects. Also, it is possible to conduct numerous tests simultaneously. When using the same infrastructure, the requirements of various commits and tests could conflict due to their varying setup requirements.
  Inadequately set up environments can cause tests and deployments to fail, which in turn slows down the continuous integration and continuous delivery process.

• Version Control Issues
  A number of tools, parts, and procedures are usually needed for conventional CI/CD pipelines. In order to execute all of the operations once a pipeline is live, a stable version is required. Updates that aren't expected have the potential to halt the entire pipeline and cause deployment delays.
  The time spent on version control by DevOps teams is considerable. Within the CI/CD pipeline, some teams may designate a particular department or job function to handle version control management.
  A very annoying situation is when an automatic update activates and imposes a new version update on a crucial process. The process will be interrupted, and there may be compatibility issues with the existing CI/CD pipeline due to the new version. The teams will then need to reorganize the entire CI/CD deployment procedure to accommodate the new version.

• Integration with Existing Processes
  Integrating a new continuous integration and continuous delivery pipeline into an existing workflow or project adds another layer of complexity to adopting agile DevOps principles. Since modifying one workflow might influence other processes to change, which could lead to a complete reorganization, large legacy projects are often hard to manage.
  Planning, having a lot of knowledge, and having the right tools are all necessary to implement CI/CD in an ongoing project. Reducing latency and ensuring excellent quality may incur substantial costs if the implementation is not well-planned.

• Cross-Team Communication
  A big workforce, generally split into multiple teams with distinct roles, is usually involved in CI/CD pipelines. A CI/CD pipeline's biggest challenge is usually interpersonal communication, particularly when it comes to diverse teams. Quick problem resolution and uninterrupted pipeline operation depend on clear and constant communication.
  The shortcomings of non-human communication are just one of many reasons why human interaction is crucial. For instance, automated tools could produce inaccurate results without providing the developer with the correct information to fix the problem. Here, other people could pass the message on to the right person.

Popular CI/CD Tools

Tools for continuous integration and delivery (CI/CD) automate code compilation, unit testing, and deployment, which simplifies the development workflow. These solutions make it easy for developers to work together by integrating with version control systems. They assist in reducing the likelihood of defects and improving software stability by providing real-time comments on code quality and identifying problems early in the development cycle.

Several popular CI/CD tools are listed below:

• Jenkins: A plugin-rich, versatile automation server for software development lifecycle management.
• GitLab CI/CD: Code build, test, and deployment automation made easy with GitLab's integrated CI/CD solution.
• Travis CI: It is a continuous integration (CI) platform that allows you to automate builds and tests in many languages. It was built specifically for GitHub projects.
• CircleCI: Integrated with Docker and Kubernetes, this scalable CI/CD platform offers superior caching and is tailored for performance.

Summing Up

With each new version of CI/CD, the gap between development and operations is shrinking, freeing up developers to concentrate on making business apps better. To simplify the build, test, and deploy procedures, automation is essential. By utilizing automated testing to guarantee functioning and fewer code pieces connected together, the trend towards containers and microservices streamlines the development of enterprise applications.