To create a plugin system that supports hot-swapping of plugins during runtime in Golang, you can follow these steps:
Define an interface: Start by defining an interface that represents the common behavior for all plugins you want to create. This interface should include the methods or functions that you expect all plugins to implement.
Implement plugins: Develop multiple plugins that conform to the defined interface. Each plugin should be implemented as a separate Go package and expose the necessary methods or functions.
Plugin loader: Create a plugin loader, responsible for dynamically loading and managing the plugins. This loader should be a separate Go package that can be imported into your main application.
Loading plugins: Use Go's plugin package to load the plugins at runtime. The plugin package provides functions like Open() and Lookup() to load and access the plugin's exported symbols.
Hot-swapping: To support hot-swapping of plugins, you need to monitor the plugin files for changes. You can use a file watcher library like fsnotify to detect changes in plugin files.
Reloading plugins: When a change is detected, unload the existing plugins and reload them using the plugin package. You might want to store information about the loaded plugins (e.g., names, references) to facilitate unloading and reloading.
Managing state: Consider how you'll manage the state of the application when hot-swapping plugins. Depending on the complexity of the plugins, you may need to save the state externally and restore it after reloading the plugins.
Updating references: After reloading plugins, make sure to update any references or dependencies in your main application that may have been affected by the changes.
Error handling: Handle any errors that may occur during the loading, unloading, or reloading of plugins. Gracefully handle scenarios where plugins fail to load or are removed.
Testing and iteration: Test your plugin system thoroughly, including cases where plugins are frequently swapped during runtime. Iterate and improve the system based on your requirements.
Remember to consider any potential security risks involved in allowing dynamic loading of plugins during runtime.