Guide to use the Migration tool. From one Ignite/CosmosSDK version to any other.

Welcome to this tutorial on using the gen-mig-diffs tool, a resource for Ignite developers aiming to track and manage changes in scaffolded chains between different versions of Ignite CLI. This guide will walk you through the process of setting up and using the tool, as well as offer an alternative migration strategy.

Introduction to gen-mig-diffs

The gen-mig-diffs tool is designed to simplify the migration process by helping developers visualize code changes across multiple major versions of Ignite. When upgrading your project to a newer version of Ignite CLI, it can be challenging to track changes and ensure compatibility. This tool automates the process, providing a clear, organized view of the differences between versions.

Features

• Visualizes code changes: Easily see what has changed between two versions.
• Simplifies upgrades: Streamlines the process of migrating your project to a newer version of Ignite CLI.
• Automates diff generation: Generates migration diff files for each of Ignite's scaffold commands.
• Compare any Ignite CLI versions: Any migration of Ignite CLI versions is compatible.

Setting Up gen-mig-diffs

Prerequisites

• Go: Ensure you have Go installed on your system.

Installation Steps

1. Clone the Ignite CLI repository:

   git clone https://github.com/ignite/cli.git && \
   cd cli/ignite/internal/tools/gen-mig-diffs
   

2. Install the tool:

   go install . && gen-mig-diffs -h
   

Use gen-mig-diffs

Example Usage

To generate migration diffs between versions 0.27.2 and 28.3.0, use the following command:

gen-mig-diffs --output temp/migration --from v0.27.2 --to v28.3.0

Important Flags

• f, --from string: Specifies the version of Ignite or the path to the Ignite source code to generate the diff from.
• t, --to string: Specifies the version of Ignite or the path to the Ignite source code to generate the diff to.
• o, --output string: Defines the output directory to save the migration document.

This command will scaffold blockchains with the specified versions and display the differences, aiding developers in understanding the necessary changes for their projects.

Alternative Migration Strategy

While gen-mig-diffs provides a streamlined way to visualize changes, an alternative approach involves scaffolding a new chain and manually porting over modules from the old chain. This method can sometimes lead to a more successful migration, especially when dealing with significant changes or customizations.

Steps for Manual Migration

1. Scaffold a new chain without modules: Use the latest version of Ignite CLI to create a new project scaffold.
2. Port modules from the old chain: Copy the custom modules and configurations from your old project to the new scaffolded project.
3. Debug and resolve errors: Work through any compatibility issues and errors that arise from the differences between the old and new versions.

Benefits of Manual Migration

• Full control: Allows for a granular approach to handling changes and customizations.
• Thorough testing: Encourages comprehensive testing and debugging, ensuring that all aspects of the project are up-to-date and compatible.

Conclusion

The gen-mig-diffs tool is an excellent resource for developers looking to upgrade their Ignite projects efficiently. By visualizing the changes between versions, it simplifies the migration process. However, for those who prefer a more hands-on approach, scaffolding a new chain and manually porting modules remains a viable and often successful alternative.

By following this guide, you should be well-equipped to handle migrations in your Ignite projects, whether using gen-mig-diffs or opting for a manual approach.

Happy coding!