Display POM Version In Angular Project A Comprehensive Guide

Jul 18, 2025 by ADMIN 61 views

How to Display Your POM Version in an Angular Project Within an Nx Monorepo

Displaying the version of your application is crucial for tracking releases, debugging issues, and ensuring that users are using the correct version of your software. When you have an Angular project nested within a Maven project, especially in an Nx monorepo setup, the process might seem a bit complex. This article provides a comprehensive guide on how to effectively display the POM version in your Angular project, integrating it seamlessly within your Jenkins CI/CD pipeline.

Understanding the Context: Angular, Maven, Nx Monorepo, and Jenkins

Before diving into the technical steps, it’s essential to understand the technologies involved:

Angular: A popular open-source front-end web framework written in TypeScript, used for building dynamic web applications.
Maven: A powerful build automation tool primarily used for Java projects. It manages project dependencies, builds, and deployments.
Nx Monorepo: A set of extensible dev tools for monorepos, which are single repositories containing multiple projects. Nx helps manage and build Angular applications, libraries, and backend services efficiently.
Jenkins: An open-source automation server that enables continuous integration and continuous delivery (CI/CD) pipelines. It automates the build, test, and deployment processes.

In this scenario, you have an Angular application residing within an Nx monorepo, which is itself part of a larger Maven project. The goal is to extract the version defined in the pom.xml file (Maven's project object model) and make it accessible within your Angular application. This involves reading the pom.xml file, extracting the version, and making it available during the Angular build process. Your Jenkinsfile orchestrates the entire process, ensuring that the version is correctly injected into your application during the CI/CD pipeline.

Why Display the POM Version in Your Angular Project?

Integrating the POM version into your Angular application offers several benefits:

Version Tracking: Displaying the version number in your application's UI or admin panel makes it easy to identify which version is currently deployed. This is invaluable for debugging and maintenance.
Release Management: Knowing the exact version helps in managing releases and rollbacks. If an issue arises, you can quickly identify the version causing the problem and revert to a stable one.
Consistency: Ensuring that the version displayed in the application matches the version managed by Maven provides consistency across your build and deployment processes.
User Support: When users report issues, knowing their application version helps support teams troubleshoot problems more efficiently.

Step-by-Step Guide to Displaying the POM Version

1. Accessing the POM Version in Jenkins

First, you need to access the POM version within your Jenkinsfile. Jenkins can execute shell commands and access environment variables, making it possible to extract the version using command-line tools.

pipeline {
    agent any
    stages {
        stage('Get POM Version') {
            steps {
                script {
                    def pom = readMavenPom file: 'pom.xml'
                    env.POM_VERSION = pom.version
                    echo "POM Version: ${env.POM_VERSION}"
                }
            }
        }
    }
}

This Jenkins pipeline snippet reads the pom.xml file and extracts the version, storing it in the POM_VERSION environment variable. The readMavenPom function is part of the pipeline-maven plugin, which you may need to install in Jenkins. The echo command then prints the version to the console, verifying that the extraction was successful. This crucial step ensures the version is accessible for subsequent steps in the pipeline. The key here is to correctly read the Maven POM file and make its contents available for the rest of the build process.

2. Passing the Version to the Angular Build

Once you have the POM version in an environment variable, you need to pass it to the Angular build process. There are several ways to achieve this, such as using environment variables or creating a configuration file.

a. Using Environment Variables

You can pass the POM_VERSION environment variable directly to the Angular build command. In your Jenkinsfile, you can modify the build stage to include this variable:

stage('Angular Build') {
    steps {
        sh "ng build --configuration=$env.BUILD_CONFIG --aot --build-optimizer --vendor-chunk --common-chunk --delete-output-path --base-href=/ --deploy-url=/ --outputPath=dist/$env.APP_NAME --progress=false --source-map=false --stats-json --named-chunks --extract-licenses --output-hashing=all --define=\"VERSION=$env.POM_VERSION\""
    }
}

This example uses the --define flag in the ng build command to define a variable named VERSION with the value of POM_VERSION. This variable will then be accessible within your Angular application.

b. Creating a Configuration File

Alternatively, you can create a configuration file during the build process and include the version in it. This approach is useful if you need to pass multiple configuration variables to your Angular application.

stage('Create Config File') {
    steps {
        script {
            def configFileContent = "export const environment = {\n  production: ${env.PRODUCTION},\n  version: '${env.POM_VERSION}'\n};\n"
            writeFile file: 'src/environments/version.ts', text: configFileContent
        }
    }
}

This script creates a version.ts file in the src/environments/ directory with the version embedded in the environment object. The key here is the dynamic generation of the configuration file using the writeFile command. This ensures that the correct version from the POM is always included in the build. You can then import this file into your Angular components to access the version.

3. Accessing the Version in Your Angular Application

Now that the version is available during the build process, you can access it in your Angular components. The method you use depends on how you passed the version to the build.

a. Accessing the Version Defined via `--define`

If you used the --define flag, you can access the VERSION variable directly in your TypeScript code:

import { Component, OnInit } from '@angular/core';

declare const VERSION: string;

@Component({
  selector: 'app-version',
  template: `<p>Version: {{ version }}</p>`,
})
export class VersionComponent implements OnInit {
  version: string;

  ngOnInit(): void {
    this.version = VERSION;
  }
}

This component declares the VERSION constant and assigns its value to the version property. The template then displays the version. This method is straightforward but requires declaring the constant in your TypeScript code. The key is using the declare const syntax to tell TypeScript that this constant is available at runtime. This approach makes it easy to inject the version directly into your components.

b. Accessing the Version from a Configuration File

If you created a configuration file, you can import it and access the version from the environment object:

import { Component, OnInit } from '@angular/core';
import { environment } from '../environments/version';

@Component({
  selector: 'app-version',
  template: `<p>Version: {{ version }}</p>`,
})
export class VersionComponent implements OnInit {
  version: string;

  ngOnInit(): void {
    this.version = environment.version;
  }
}

This approach is more flexible, especially if you have other configuration variables to manage. The environment object can hold multiple configuration values, making it a scalable solution for managing your application’s settings. This method encapsulates the version along with other environment-specific configurations.

4. Updating Your `pom.xml`

Make sure your pom.xml file is correctly configured to include the necessary information. A typical pom.xml file includes the version as follows:

<project>
    ...
    <groupId>com.example</groupId>
    <artifactId>my-angular-app</artifactId>
    <version>1.0.0</version>
    ...
</project>

The <version> tag contains the version number that you want to display in your Angular application. This is the source of truth for your application's version, so ensuring it's correctly maintained is crucial. Regularly updating this version tag with each release ensures consistency across your build and deployment processes.

5. Automating the Process with Jenkins

Finally, automate the entire process using Jenkins. Your Jenkinsfile should include the steps to read the POM version, pass it to the Angular build, and build your application. A complete Jenkinsfile might look like this:

pipeline {
    agent any
    stages {
        stage('Get POM Version') {
            steps {
                script {
                    def pom = readMavenPom file: 'pom.xml'
                    env.POM_VERSION = pom.version
                    echo "POM Version: ${env.POM_VERSION}"
                }
            }
        }
        stage('Create Config File') {
            steps {
                script {
                    def configFileContent = "export const environment = {\n  production: ${env.PRODUCTION},\n  version: '${env.POM_VERSION}'\n};\n"
                    writeFile file: 'src/environments/version.ts', text: configFileContent
                }
            }
        }
        stage('Angular Build') {
            steps {
                sh "npm install"
                sh "ng build --configuration=$env.BUILD_CONFIG --aot --build-optimizer --vendor-chunk --common-chunk --delete-output-path --base-href=/ --deploy-url=/ --outputPath=dist/$env.APP_NAME --progress=false --source-map=false --stats-json --named-chunks --extract-licenses --output-hashing=all"
            }
        }
    }
}

This Jenkinsfile includes stages for getting the POM version, creating the configuration file, and building the Angular application. The stages are clearly defined, making the pipeline easy to understand and maintain. Automating the process ensures that the version is always correctly injected into your application during the CI/CD process.

Best Practices and Considerations

Security: Avoid hardcoding sensitive information in your configuration files. Use environment variables or secrets management tools for sensitive data.
Consistency: Ensure that the versioning scheme in your pom.xml aligns with your release management strategy.
Testing: Add tests to verify that the version is correctly displayed in your application.
Nx Monorepo: In an Nx monorepo, make sure you are running the commands in the correct context (i.e., within the Angular application's directory).
Error Handling: Implement error handling in your Jenkinsfile to gracefully handle cases where the POM version cannot be read or the configuration file cannot be created.

Troubleshooting Common Issues

Version Not Displaying: Double-check that the POM_VERSION environment variable is correctly set in Jenkins and that the Angular build command is correctly referencing it.
Configuration File Not Found: Ensure that the path to the configuration file is correct and that the file is being created in the expected location.
Build Errors: Check the Angular build logs for any errors related to accessing the version or configuration file.
Jenkins Permissions: Make sure that the Jenkins user has the necessary permissions to read the pom.xml file and create files in the Angular project directory.

Conclusion

Displaying the POM version in your Angular project within an Nx monorepo is a critical step for effective release management and debugging. By following this guide, you can seamlessly integrate the Maven version into your Angular application using Jenkins. This ensures that your application always displays the correct version, making it easier to track releases and troubleshoot issues. Remember to follow best practices for security, consistency, and testing to ensure a robust and reliable CI/CD pipeline. The key takeaway is that with careful planning and the right tools, integrating version information into your application can significantly improve your development workflow and the quality of your software.

By implementing these steps, you can confidently display the POM version in your Angular application, enhancing your development and deployment processes. Remember to adapt these steps to your specific project needs and environment. The effort invested in correctly displaying the version will pay off in terms of improved release management, debugging, and overall application quality.