Go SDK for Portable Plugins

The Go SDK allows developers to build portable plugins in the Go programming language. It provides interfaces for source, sink, and function extensions, as well as runtime startup routines to manage the plugin lifecycle.

Development

Dependency Configuration

Import the Go SDK module:

require github.com/lf-edge/ekuiper/sdk/go v0.0.0

Implement the extension interfaces defined in github.com/lf-edge/ekuiper/sdk/go/api.

Implement Extension Interfaces

• Source Interface:

  type Source interface {
      Open(ctx StreamContext, consumer chan<- SourceTuple, errCh chan<- error)
      Configure(datasource string, props map[string]interface{}) error
      Closable
  }

• Sink Interface:

  type Sink interface {
      Open(ctx StreamContext) error
      Configure(props map[string]interface{}) error
      Collect(ctx StreamContext, data interface{}) error
      Closable
  }

• Function Interface:

  type Function interface {
      Validate(args []interface{}) error
      Exec(args []interface{}, ctx FunctionContext) (interface{}, bool)
      IsAggregate() bool
  }

Main Entry Program

Implement an executable entry point that calls sdk.Start:

package main

import (
    "os"
    "github.com/lf-edge/ekuiper/sdk/go/api"
    sdk "github.com/lf-edge/ekuiper/sdk/go/runtime"
)

func main() {
    sdk.Start(os.Args, &sdk.PluginConfig{
        Name: "mirror",
        Sources: map[string]sdk.NewSourceFunc{
            "random": func() api.Source {
                return &randomSource{}
            },
        },
        Functions: map[string]sdk.NewFunctionFunc{
            "echo": func() api.Function {
                return &echo{}
            },
        },
        Sinks: map[string]sdk.NewSinkFunc{
            "file": func() api.Sink {
                return &fileSink{}
            },
        },
    })
}

The names declared in PluginConfig must match the names defined in the plugin JSON metadata.

Refer to the Go SDK Mirror Example for complete sample code.

Packaging

Compile the main program with go build:

go build -o mirror main.go

Package the executable and the JSON metadata file into a .zip archive. Refer to Packaging Portable Plugins for details.