Go Bot

Go Bot is a library used to create commands, inputs and bot services for Micro

Commands

Commands are functions executed by the bot based on text based pattern matching.

Write a Command

import "github.com/micro/go-bot/command"

func Ping() command.Command {
	usage := "ping"
	description := "Returns pong"

	return command.NewCommand("ping", usage, desc, func(args ...string) ([]byte, error) {
		return []byte("pong"), nil
	})
}

Register the command

Add the command to the Commands map with a pattern key that can be matched by golang/regexp.Match

import "github.com/micro/go-bot/command"

func init() {
	command.Commands["^ping$"] = Ping()
}

Rebuild Micro

Build binary

cd github.com/micro/micro

// For local use
go build -i -o micro ./main.go

// For docker image
CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -ldflags '-w' -i -o micro ./main.go

Inputs

Inputs are plugins for communication e.g Slack, HipChat, XMPP, IRC, SMTP, etc, etc.

New inputs can be added in the following way.

Write an Input

Write an input that satisfies the Input interface.

type Input interface {
	// Provide cli flags
	Flags() []cli.Flag
	// Initialise input using cli context
	Init(*cli.Context) error
	// Stream events from the input
	Stream() (Conn, error)
	// Start the input
	Start() error
	// Stop the input
	Stop() error
	// name of the input
	String() string
}

Register the input

Add the input to the Inputs map.

import "github.com/micro/micro/bot/input"

func init() {
	input.Inputs["name"] = MyInput
}

Rebuild Micro

Build binary

cd github.com/micro/micro

// For local use
go build -i -o micro ./main.go

// For docker image
CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -ldflags '-w' -i -o micro ./main.go

Commands as Services

The micro bot supports the ability to create commands as microservices.

How does it work?

The bot watches the service registry for services with it's namespace. The default namespace is go.micro.bot. Any service within this namespace will automatically be added to the list of available commands. When a command is executed, the bot will call the service with method Command.Exec. It also expects the method Command.Help to exist for usage info.

The service interface is as follows and can be found at go-bot/proto

syntax = "proto3";

package go.micro.bot;

service Command {
	rpc Help(HelpRequest) returns (HelpResponse) {};
	rpc Exec(ExecRequest) returns (ExecResponse) {};
}

message HelpRequest {
}

message HelpResponse {
	string usage = 1;
	string description = 2;
}

message ExecRequest {
	repeated string args = 1;
}

message ExecResponse {
	bytes result = 1;
	string error = 2;
}

Example

Here's an example echo command as a microservice

package main

import (
	"fmt"
	"strings"

	"github.com/micro/go-micro"
	"golang.org/x/net/context"

	proto "github.com/micro/go-bot/proto"
)

type Command struct{}

// Help returns the command usage
func (c *Command) Help(ctx context.Context, req *proto.HelpRequest, rsp *proto.HelpResponse) error {
	// Usage should include the name of the command
	rsp.Usage = "echo"
	rsp.Description = "This is an example bot command as a micro service which echos the message"
	return nil
}

// Exec executes the command
func (c *Command) Exec(ctx context.Context, req *proto.ExecRequest, rsp *proto.ExecResponse) error {
	rsp.Result = []byte(strings.Join(req.Args, " "))
	// rsp.Error could be set to return an error instead
	// the function error would only be used for service level issues
	return nil
}

func main() {
	service := micro.NewService(
		micro.Name("go.micro.bot.echo"),
	)

	service.Init()

	proto.RegisterCommandHandler(service.Server(), new(Command))

	if err := service.Run(); err != nil {
		fmt.Println(err)
	}
}