go-grpc-plugin.md

Golang plugin over gRPC

It is recommended to use golang plugin over gRPC in most cases. This should be the most stable solution with higher performance.

install SDK

Before you develop your golang plugin, you need to install an dependency as SDK.

$ go get -u github.com/httprunner/funplugin

create plugin functions

Then you can write your plugin functions in golang. The functions can be very flexible, only the following restrictions should be complied with.

• package name should be main.
• function should return at most one value and one error.
• in main() function, Register() must be called to register plugin functions and Serve() must be called to start a plugin server process.

Here is some plugin functions as example.

package main

import (
	"fmt"

	"github.com/httprunner/funplugin/fungo"
)

func SumTwoInt(a, b int) int {
	return a + b
}

func SumInts(args ...int) int {
	var sum int
	for _, arg := range args {
		sum += arg
	}
	return sum
}

func Sum(args ...interface{}) (interface{}, error) {
	var sum float64
	for _, arg := range args {
		switch v := arg.(type) {
		case int:
			sum += float64(v)
		case float64:
			sum += v
		default:
			return nil, fmt.Errorf("unexpected type: %T", arg)
		}
	}
	return sum, nil
}

func main() {
	fungo.Register("sum_ints", SumInts)
	fungo.Register("sum_two_int", SumTwoInt)
	fungo.Register("sum", Sum)
	fungo.Serve()
}

You can get more examples at fungo/examples/.

build plugin

Once the plugin functions are ready, you can build them into the binary file xxx.bin. The file suffix of .bin is by convention and should not be changed.

$ go build -o fungo/examples/xxx.bin fungo/examples/hashicorp.go fungo/examples/debugtalk.go

use plugin functions

Finally, you can use Init to initialize plugin via the xxx.bin path, and you can call the plugin API to handle plugin functionality.

The complete log example can be found in the file hashicorp_grpc_go.log.