FunPlugin

What is FunPlugin?

FunPlugin is short for function plugin, and I hope you can have fun using this plugin too.

This plugin project comes from the requirements of HttpRunner+, because we need to implement some dynamic calculations or custom logic processing in YAML/JSON test cases. If you have used HttpRunner before, you must be impressed by debugtalk.py, which allows us to customize functions very easily and reference them in plain text test cases.

As the HttpRunner project evolves, we expect users to have more choices besides Python when writing custom functions, such as Golang, Java, Node, C++, C#, etc.

FunPlugin achieves this goal well and grows into an independent project that not only serves HttpRunner+, but can also be easily integrated into other golang projects.

How to use FunPlugin?

FunPlugin is mainly based on hashicorp plugin, which is a golang plugin system over RPC. It supports serving plugins via gRPC, which means plugins can be written in any language. You can find the official programming languages supported by grpc here.

Integrating FunPlugin is very simple. You only need to focus on two parts.

• client side: integrate FunPlugin into your golang project, call plugin functions at will.
• plugin side: write plugin functions in your favorite language and build them to plugin binary

client call

FunPlugin has a very concise golang API that can be easily integrated into golang projects.

1, use Init to initialize plugin via plugin path.

func Init(path string, options ...Option) (plugin IPlugin, err error)

• path: built plugin file path
• options: specify extra plugin options
  • WithDebugLogger(debug bool): whether to print debug level logs in plugin process
  • WithLogFile(logFile string): specify log file path
  • WithDisableTime(disable bool): whether disable log time
  • WithPython3(python3 string): specify custom python3 path

2, call plugin API to deal with plugin functions.

If the specified plugin path is valid, you will get a plugin instance conforming to the IPlugin interface.

type IPlugin interface {
	Type() string
	Has(funcName string) bool
	Call(funcName string, args ...interface{}) (interface{}, error)
	Quit() error
}

• Type: returns plugin type, current available types are go-plugin/hashicorp-rpc-go/hashicorp-grpc-go/hashicorp-grpc-py
• Has: check if plugin has a function
• Call: call function with function name and arguments
• Quit: quit plugin

You can reference hashicorp_plugin_test.go and go_plugin_test.go as examples.

plugin server

In RPC architecture, plugins can be considered as servers. You can write plugin functions in your favorite language and then build them to a binary file. When the client Init the plugin file path, it starts the plugin as a server and they can then communicates via RPC.

Currently, FunPlugin supports 3 different plugins via RPC. You can check their documentation for more details.

• Golang plugin over gRPC, built as xxx.bin (recommended)
• Golang plugin over net/rpc, built as xxx.bin
• Python plugin over gRPC, no need to build, just name it with xxx.py

You are welcome to contribute more plugins in other languages.

• Java plugin over gRPC
• Node plugin over gRPC
• C++ plugin over gRPC
• C# plugin over gRPC
• etc.

Finally, FunPlugin also supports writing plugin function with the official go plugin. However, this solution has a number of limitations. You can check this document for more details.