Speed up Jenkins Pipelines with Caching

Importance of Caching

Efficient caching is crucial in optimizing build processes within continuous integration environments. Caching helps reduce build times by storing and reusing previously computed results, avoiding redundant computations and dependencies installation.

Types of Caching

1. Dependencies Caching (node_modules)

Caching the node_modules directory ensures that npm packages are stored and reused across builds. This reduces the time spent on installing dependencies if the package-lock file remains unchanged.

2. Application Compilation Caching (.next/cache)

Caching the results of the Next.js application compilation, such as the .next/cache directory, accelerates the build process by reusing previously compiled assets. This is especially valuable when the source code remains unchanged.

Jenkins "Job Cacher" Plugin

The "Job Cacher" plugin in Jenkins provides a solution for caching in CI/CD pipelines. It offers a flexible mechanism to cache and restore specific directories based on custom criteria.

maxCacheSize Parameter

The maxCacheSize parameter allows you to set a maximum size limit, in megabytes, for all configured caches associated with a Jenkins job. When the cumulative size exceeds this limit, the plugin initiates a cleanup, deleting all caches and starting the next build from an empty cache. This prevents caches from growing indefinitely, with the occasional downside of periodic fresh builds without a cache. Setting maxCacheSize to zero or leaving it empty skips checking the cache size.

Job Cacher with S3 Integration

The "Job Cacher" plugin provides the flexibility to integrate with alternative storage solutions, including Amazon S3. This allows you to offload caching to scalable and cost-effective cloud storage services.

Configuration Options

• Storage Type Configuration: You can configure the storage type in the global configuration section of Jenkins, enabling integration with on-controller storage, AWS S3, and S3-compatible services.
• Additional Requirements: Check the plugin documentation for any additional requirements when integrating with S3 or S3-compatible services.

Examples for Each Type of Caching

1. Dependencies Caching (node_modules)

stage("Restore npm packages") {
    steps {
        writeFile file: "next-lock.cache", text: "$GIT_COMMIT"
 
        cache(caches: [
            arbitraryFileCache(
                path: "node_modules",
                includes: "**/*",
                cacheValidityDecidingFile: "package-lock.json"
            )
        ]) {
            sh "npm install"
        }
    }
}

2. Application Compilation Caching (.next/cache)

stage("Build") {
    steps {
        writeFile file: "next-lock.cache", text: "$GIT_COMMIT"
 
        cache(caches: [
            arbitraryFileCache(
                path: ".next/cache",
                includes: "**/*",
                cacheValidityDecidingFile: "next-lock.cache"
            )
        ]) {
            sh "npm run build"
        }
    }
}

Conclusion

Implementing caching in Jenkins pipelines for Next.js projects significantly improves build efficiency. By intelligently caching dependencies and application compilation results, developers can experience faster build times, making the CI/CD process more streamlined and responsive. The "Job Cacher" plugin simplifies the caching process, providing a reliable solution for optimizing build workflows.

Note: While this article demonstrates the implementation using Jenkins as the CI/CD tool and Next.js as the framework, the principles of caching and optimizing developer productivity are applicable across various CI/CD tools and software applications. The concepts discussed here can be adapted to suit different technology stacks, ensuring efficient and streamlined development workflows in diverse environments.