Jenkins Best Practices every Developer must know

Jenkins is a popular CI/CD automation server with nearly 1.6 million customers worldwide. It is open source and supports a wide range of languages and repositories using pipelines. It seamlessly integrates your builds, tests, and deployment tools.

A lot of developers use Jenkins for DevOps. Hence, it is essential to know the best practices and follow them to make the most out of them.

Jenkins Best Practices

Jenkins is used to continuously develop and install your software projects, making it more straightforward for developers to incorporate design changes and for users to get a new build. Jenkins software’s ability to track recurring tasks while a project is being developed is what made it so famous. 

For instance, if the team is working on projects, Jenkins ensures your project updates and updates if there are any mistakes at the beginning of the process. To make the best out of it, here are some of the best practices of Jenkins every developer must know and follow:

1. Always create a backup of the Jenkins Home Directory

Why is it Important?

Jenkins’ home directory includes a large amount of data, such as job setups, build logs, plugin configurations, and so on, which we can afford to lose. This may be performed via Jenkins plugins or by creating a process to take backups. It’s one of Jenkins’ most important best practices.

How to implement it?

• Backup Plugin: Using the plugin is NOT advised because, for the backup of your data, you must manually start it.
• Jenkins has halted any improvements to it because better options are available.
• Thin Backup Plugin: One of the most useful plugins provides scheduled periodic backups.
• Manage Jenkins -> Manage Plugins -> Install the plugin. Click the ‘Available’ tab and search for ‘Thin Backup.’
• After installation, navigate to Manage Jenkins -> ThinBackup -> Settings.
• Configuration options for the plugin are self-explanatory, and for any ambiguity, ‘?’ beside every setting is a boon!
• To test the backup, click ‘Backup now.’
• Periodic Backup Plugin: This is a substitute to the existing ‘Backup Plugin,’ which will run regularly once configured.

The plugin specifies three extension points:

• File Manager: It specifies which files should be backed up and the rules for restoring those files. Confidently, for instance, it will only select configuration XML files.
• Storage: It describes how backups are archived and unarchived. For instance, “ZipStorage” will zip up backup data after compression.
• Location: It specifies the localization of the backups by location. For instance, “LocalDirectory” will place the backup files in the designated directory.

Establish a regular backup job.

• When building a new Jenkins job, select “Freestyle project.”
• Select “None” for SCM.
• In Build Triggers, choose “Build periodically,” and in Schedule, set the frequency. Giving “H 12 * * *,” for instance, will back up each day at 12.25.30 GMT.
• Add a build step called Execute Shell to use this file as the build job and command.

Jenkins configuration backups are stored in Google Cloud.

This works best if you have a Google Cloud Kubernetes cluster with a Jenkins web server deployed over it. Connect to the cloud via installing the Cloud Storage plugin and using the “Thin Backup plugin”. The recommended Jenkins security best practice is the use of Thin Plugin in connection with either setting up a pipeline or configuring a task. 

2. Create a Unique Job or Project for each Newly Created Maintenance or Development Branch

Why is it Important?

You can encourage future parallel development and optimize the benefit of probing bugs by setting various jobs/projects for each branch, which lowers risk and boosts developer productivity.

How to implement it?

The program divides tests into various, nearly equal-sized units based on the previous test execution time. The exclusion list is then created for each component.

Any testing job that requires the use of this tool

• Create XML files that are JUnit compliant.
• Accept a file containing a test-exclusion list.

You are responsible for setting up the build process to respect the exclusion file.

3. Avoid Resource Collisions when Running Parallel Jobs

Why is it Important?

You must prevent collisions between concurrent jobs that could damage your Jenkins pipeline if they require exclusive access to a service or establish one. Giving access to resources simultaneously might cause deadlock situations, and the system might crash. Hence, DevOps experts strongly advise using it as one of the CI/CD best practices.

How to implement it?

Build conflicts are avoided by allocating separate ports for concurrent Project runs. Throttle Parallel Builds Plugin is an excellent example of a persistent resource like a database that needs to be locked.

4. To Manage Dependencies, use “File Finger-printing”

Why is it Important?

Keeping track of which version is used and which version might be complicated when establishing interdependent projects on Jenkins. To simplify this, make the most of “file fingerprinting,” which Jenkins supports.

How to implement it?

The configuration of all pertinent projects must be set to record all biometrics of the following: 

• Jar files generated by your project.
• Jar files that are necessary for your project.

Go to your project to create a job to capture fingerprints. For clarity, you can take note of fingerprints.

5. Create a Scalable Jenkins Pipeline

Why is it Important?

Shared Libraries are the apex of adoption. Compared to a standard programming library, shared libraries provide version-controlled Pipeline code, which can be saved and used via any Source Control Management (SCM).

How to implement it?

You’ll require a source file having a consistent structure kept in your SCM, and then you’ll link the library to your Jenkins instance using your SCM’s plugin and:

• Enable Global Shared Libraries by going to Manage Jenkins -> Configure System -> Global Pipeline Libraries or
• At the folder level, by controlling that particular folder.
• Using the library name as ‘@Library‘ within the Jenkins file will enable a pipeline to use that shared library.

6. Maintain higher Code Coverage and perform System Testing as part of the Pipeline

Why is it Important?

By lowering UAT and product problems, maintaining 90% code coverage ensures a higher ROI. While better coverage alone cannot ensure code quality, displaying code coverage and data can assist your programmers, and QA avoids defects early in the development cycle.

How to implement it?

1. The Jenkins Cobertura plugin lets you download Cobertura’s code coverage reports.

Configuring the Cobertura Plugin:

• Cobertura can be installed by learning to Handle Jenkins -> Manage Plugins.
• Set up the build script for your project to produce Cobertura XML reports.
• Activate the publisher for “Publish Cobertura Coverage Report.”
• Indicate the location of the folder where the coverage.xml reports are produced.
• Set the coverage measurement targets to correspond with your objectives.

2. Keep track of code coverage. Most of the repetitive work for other plugins, such as Cobertura, is handled by an API plugin, a single API plugin.

The critical functions of this API plugin are:

• Locating coverage reports based on user preferences.
• To transform reports into a standard format, use adapters.
• Assemble reports in a standard format that has been digested, then display the results in a chart.

Therefore, providing code coverage requires the creation of an adapter that does one thing, namely, convert coverage reports into a standardized way.

Conclusion 

Jenkins is a Java-based DevOps solution for continuous integration/continuous delivery/continuous deployment (CI/CD) automation. Pipelines are used to build CI/CD workflows.

As an open-source tool server, Jenkins makes integrated business and continuous delivery possible by automating, developing, testing, and deploying software development processes. It runs on Apache Tomcat or another servlet container.

Letting Jenkins security best practices manage its database and performing network access depending on permission/user matrix are best practices for using it and can be applied at any development stage. 

Encouraging application teams to update to the Shell phase so they can take control of shared libraries and Jenkinsfiles and avoid writing complicated Groovy scripts. Always define a descriptive pipeline and use an auto status plugin to track your channel. A crucial task that should be set up to execute automatically is backing up! 

Lastly, excellent code coverage tests always result in a solid product or piece of software. Your approach for your Jenkins pipeline must include it as a critical component. It is also regarded as one of the top-rated Jenkins CI CD best practices.