Devops CI: Continuous Integration in DevOps
By Sourojit Das, Community Contributor - February 24, 2023
Continuous integration (CI) is an essential component of DevOps pipelines and agile development workflows. The purpose of this technique is to minimise the number and complexity of merge conflicts by introducing frequent mainline pushes. Once code has been integrated and tested, it is updated on local machines with frequent pulls so that developers are constantly working with the most recent version of the code.
In Traditional Integration methods, each developer receives a copy of the code from the central repository, starts from the same spot and continues working. They work as a team or individually and modify classes, methods, functions, etc to finish the task at hand. However, since all of them work without a clear picture of what the others are doing this leads to a change in the context in which the code is being written.
The issues from this opacity only increase with the size of the team and the amount of time passed since a developer got the most recent copy of the codebase from the repository.
It is to overcome these challenges that Continuous Integration came into being.
Defining the term: DevOps CI
Continuous integration (CI) is a pillar of the DevOps pipelines and an integral component of agile development workflows. This strategy aims to reduce the number and complexity of merge conflicts by performing frequent mainline pushes. Once code has been merged and tested, it is frequently pulled to local workstations, so developers are constantly working with the most recent version.
CI focuses on the build and integration phases of the conventional software development lifecycle. The CI pipeline is realized by combining automation (tools and services) with cultural adjustments (aligning team values and goals to DevOps principles).
In conventional software development methodologies, such as the waterfall model, features would be assigned to developers to build throughout the sprint. At the conclusion of the sprint, the engineers integrate their completed code to produce the application’s final codebase.
This strategy seems perfect, but in practice, two developers may find themselves modifying the same section of a file.
What happens if Developer A extends the functionality of a code snippet to accommodate their feature, but Developer B deletes the identical code snippet? Both have been using distinct versions of the same file for weeks, and now their modifications fundamentally disagree. This conflict resolution procedure is laborious and time-consuming.
It is clearly visible how this hazard came to be known as “merge hell” or “integration hell” when multiplied by the number of engineers working on hundreds or thousands of files for enterprise-scale applications.
CI solves this inefficiency in traditional development pipelines by increasing the merging and integration frequency from weeks to days or even hours via automation. Now, merge conflicts are significantly smaller and simpler in scope, accelerating the development team’s ability to resolve them. In addition, developers are now using a codebase that mirrors the changes made by their peers, ensuring that everyone is on the same page.
Apart from solving this issue, Continuous Integration has a number of other benefits to enterprises.
Benefits of CI to Enterprise
Continuous Integration in DevOps has several advantages for Enterprise organizations. Some of them are:
- Defects are identified faster, and overall confidence in the software increases
Every commit triggers automatic code review and testing. If the code fails, developers are told promptly to fix it. Developers now regularly validate their work instead of waiting until the conclusion of the development phase since CI encourages daily commits. Automated test feedback gives development teams more trust in the product. Since they tested each new feature or component against project criteria, the final product is more likely to meet them.
- Improves overall visibility of processes to the organization
Tools that construct CI pipelines can also monitor the generation of features and other development objectives. This information is also utilized to keep other stakeholders aware of the deployment schedule.
The operations team can track when they can anticipate receiving release packages from development. Business teams may monitor the estimated delivery date for new features so they can keep their customers informed, and marketing teams can design marketing collateral and campaigns for the product’s new capabilities as they are being developed rather than after release.
- Constant Availability of a Testable Build
As changes are made, code is continuously integrated and tested against test cases. This guarantees that the quality assurance (QA) team always has a tested build of the application to examine for performance and configuration requirements.
Instead of detecting defects after the coding process is complete, the QA team can convey them to the development team, hence accelerating the turnaround time.
- Provides the Explicit Definition of Requirements
The full benefits of CI can only be realized with a solid testing approach. Otherwise, a development team may only be able to streamline the process of committing faulty code.
This emphasis on testing provides additional incentive for business and development teams to properly identify objectives at the beginning of the life cycle. It enables the engineers to develop the necessary test cases to confirm that the code satisfies these objectives, for which careful planning is required.
The first step that many development teams take to accelerate the software lifecycle is continuous integration. Continuous delivery is the subsequent stage, which automates the release of the merged code for manual deployment.
Some organizations augment this methodology with continuous deployment, which automates the release and deployment processes such that the code enters production without the intervention of a person. These strategies collectively constitute the CI/CD pipeline.
Now that an understanding of Continuous Integration and its importance has been established, it is crucial to understand how it works.
How Does CI Work
CI enable software developers to divide responsibilities and code features separately in parallel. A few distinct tool sets are necessary to develop a CI pipeline that successfully supports this process. To track and integrate changes, a development team must first implement a version control system.
A code repository is then required by a CI pipeline to hold the codebase. Git and GitHub are a popular version control system and repository combo. Finally, a testing suite is required for the pipeline. This subset of tools can be used to do code quality checks and syntax reviews before committing work, as well as unit testing after the codebase has been compiled and the application has been constructed.
Once the pipeline has been choreographed with the appropriate tools, the following would be an example of a CI workflow:
- The Developer checks out code to their workstation for editing.
- The developer commits modifications to the repository.
- Prior to accepting a commit, the code’s quality and syntax are examined.
- Commit initiates a build of the application.
- If the application cannot be constructed, the team is notified to address the problem.
- The build server executes unit tests on an application.
- If the application passes the test cases, the team is notified that the code can be merged.
- If the program fails test cases, the code is returned to the development team for bug fixes.
- This cycle should be repeated throughout the development phase.
Follow-up Read: Accelerate CI/CD pipelines with Parallel Testing
Performing CI with Jenkins
Jenkins is an open-source, Java-based automation tool that may be customised with CI-specific plugins. Jenkins is a continuous integration and delivery solution that streamlines the software development and testing processes through automation.
It is a continuous integration and delivery system that automates the process of building and testing software, making it simpler for both developers to incorporate changes and end users to receive the latest version. It also integrates with a wide variety of testing and deployment tools, so the product can be distributed continually.
Incorporating Jenkins into enterprise processes allows the automation of software development processes and releases products faster. Jenkins unifies several steps in the software development life cycle, such as compilation, documentation, testing, packaging, staging, deployment, and static analysis.
It may also be used with a broad range of testing and deployment tools, allowing for consistent product dissemination. Automation of the software development process and expedited product releases are both possible with Jenkins’ addition to the DevOps infrastructure. Jenkins streamlines several phases of the SDLC into one, including coding, testing, packaging, staging, deployment, and static analysis.
For the purposes of this article a simple example is considered. A company has obtained a project with four modules. These have been allocated to two developers. A Continuous Delivery pipeline has been implemented to maintain consistency in development, where a single job will have two modules. These jobs are synchronized in a pipeline, and the build is checked at regular intervals. Jenkins was provided the project path from GitHub, and a build trigger option was set up after fixed time intervals through Jenkins.
Step 1. Open Jenkins on the designated port
Step 2. Create a new job with a new name
Step 3. Pull the Source Code and proceed to build.
The second job can be created similarly.
Step 4. The build trigger is then set up as below
Step 5. Clicking on Build Now will set up the build job
Must Read: Continuous Integration with Jenkins
A Final Word
Enterprises should consider leveraging testing platforms like BrowserStack Automate, which easily integrate into developers’ CI/CD pipelines to enable agile teams to scale up, to get the most out of a CI/CD strategy.
BrowserStack integrates with various CI/CD tools to facilitate the implementation of DevOps. This includes Jira, Jenkins, TeamCity, Travis CI, and more technologies.
It also provides a cloud Selenium grid of 3000+ real browsers and devices for testing purposes. Moreover, built-in debugging tools allow testers to instantly detect and address errors.
At this point, implementing a CI/CD pipeline is non-negotiable. CI/CD provides tools and procedures that benefit developers in order to adopt discipline, efficiency, and high levels of quality control in software development. A careful combination of human and automated tests can be used to build a CI/CD pipeline that will speed up development cycles and give better user experiences.