Migrating to IBM Dependency Based Build (DBB) V3

IBM's Dependency Based Build (DBB) is a powerful tool for automating mainframe application builds. This blog highlights the steps in migrating from DBB V2 to V3, highlighting the key differences, advantages, and steps to transition effectively.

What is DBB V2?

DBB V2 offers:

• • Java APIs: A framework to automate mainframe builds. 
  • Groovy-based Support: IBM’s open source and no-charge ‘dbb-zappbuild’ framework leverages Groovy scripts for application builds. Due to the underlying APIs being the same for both DBB v2 and v3, this framework continues to be supported by IBM within the DBB product. 
  • Integration: Designed to plug into any major CI/CD workflow.

What’s New in DBB V3?

DBB V3 introduces:

• • Enhanced API Support: In additions to ‘dbb-zappbuild; V3 introduces a YAML-based framework called zBuilder.
  • YAML-Driven Architecture: Simplifies defining and managing build configurations – no scripting knowledge required.
  • Improved IDE Compatibility: Works seamlessly with VS Code and IDz for enhanced developer experiences.
  • Integration: Designed to plug into any major CI/CD workflow.
     

zBuilder Architecture

Below is a visual representation of DBB V3’s zBuilder architecture.  On the right side, applications define specific build properties for their code in their repository which are combined with global system properties on the left-side.  
Developers can trigger builds from their IDE using the zBuilder ‘User’ lifecycle process to build one program at a time. Pipelines use the ‘Impact’ lifecycle to build all program changes including impacted programs after changing copybooks or subprograms.

Lifecycles define a list of tasks that the build framework with execute. Tasks are building blocks configured in the YAML framework.

DBB V3 IDE Configurations

Both Microsoft VS Code® and IBM IDz® use a standardized build configuration file, ‘ZAPP.YAML’ , to launch DBB from the desktop.

ZAPP (Z APPlication) files introduce a new approach to simplifying application build configuration for individual developers and development teams. 

In cases where team members can choose between IDz (on Eclipse) or IBM Developer for z/OS on VS Code, the example below illustrates how to configure a ZAPP file that is compatible for both IDEs. Each profile specifies local user properties, such as the HLQ used by DBB to allocate MVS PDSs, as well as the DBB V3 launch command. 

Comparing DBB V2 and V3

This section highlights some common configurations between dbb-zappbuild and zBuilder as a guide in the migration effort. 

• Scripting Framework
  • V2: uses dbb-zappbuild groovy scripts like <language>.groovy.
  • V3: zBuilder is a non-scripting YAML-based approach using files like <language>.yaml.
    While a non-scripting approach can be easier to implement, zBuilder supports injecting ‘custom tasks’ using groovy scripts within the YAML when more complex processing is needed.
    
     
• System Properties

 System properties are configurations managed by Administrators that apply to all application builds.   This includes items such as compiler system libraries, PDS allocation parameters and more.

• • V2: dbb-zappbuild system properties

• • V3: zBuilder system properties 

• Application Properties

Application properties are used to define specific application build values like compiler or link options.  

• • V2: dbb-zappbuild application properties are defined in a set of files in the applications ‘application-conf’ folder.
  • V3: zBuilder  properties are defined in a application file called ‘dbb-app.yaml’.
    
    

Steps to Migrate from DBB V2 to V3

1. Follow the Official Guide - Reference: DBB V3 Getting Started Guide
2. Install DBB V3 - Use the default configurations provided in the installation directory.
3. Reconfigure Tools -Reconfigure Tools - Update your IDE and CI pipelines to integrate zBuilder.
4. Define System-Level YAML Files - Include files like dbb-build.yaml and language-specific YAML files (e.g., Cobol.yaml).
5. Test and Validate - Perform extensive testing to ensure smooth operation.
6. Train Development Teams - Educate teams on using YAML configurations and the new build processes.

Special Consideration -In order to preserve DBB V2 application metadata when migrating, it is recommended to install DBB 3.0.2 (which is planned for GA in 2025 Q2).”

Accelerating your Migration to DBB V3

As an aid in migrating to DBB V3 zBuilder, refer to the IBM Z® DevOps Acceleration Program site which offers a set of DevOps CI/CD pipeline templates that are compatible with DBB V3.

Templates for all the major DevOps orchestrators are available in the ‘implementing Pipeline actions” section.

For example, the GitHub Actions link references templates that include DBB V3 zBuilder back-end scripts.

Conclusion

Migrating to DBB V3 offers a streamlined build process, modernized configurations, and enhanced IDE support. Following the outlined steps ensures a smooth transition, enabling your organization to leverage the full potential of DBB V3.

Migrating to DBB V3 offers a streamlined build process, modernized configurations, and enhanced IDE support. Following the outlined steps ensures a smooth transition, enabling your organization to leverage the full potential of DBB V3.

Additional References

·  DBB V3 Getting Started:  Getting started with DBB zBuilder - IBM Documentation

·  Blog: IBM Dependency Based Build (DBB) v3.0.0 has arrived!

·  IBM Z DevOps Acceleration Program:  IBM Z DevOps Guide | IBM Z DevOps Guide