erlangzhang / imapmq

:inbox_tray: IMAP based message broker client

IMAPMQ is an IMAP based message broker client. It provides a simple interface for publishing, subscribing and dequeuing messages. It also supports concurrent access to the same message queue. Based on go-imap.

How it works

IMAPMQ treats IMAP mailboxes as queues. In order to add a message to a queue, IMAPMQ appends an email to the mailbox.

Features

• IMAPMQ can connect to any IMAPv4rev1 server with the CONDSTORE extension
• Publish/Subscribe
• Message Queue
• Message format agnostic
• No polling, the IMAP server notifies the client of new messages thanks to the IDLE command
• Concurrency aware: multiple dequeuing instances can work on the same queue
• Bring your own GUI: any IMAP client would do

Installing

$ go get github.com/mikaa123/imapmq

Example: A simple chat

The following example connects to an IMAP account, and creates a queue based on the INBOX mailbox. It spawns a goroutine that subscribes to the "chat" topic and listens to the returned channel. Anytime a user writes something and press enter, a new "chat" message is published to the queue.

You need to have an IMAP server to connect to. If you don't, you can create a gmail account. Make sure you enable IMAP (more info here) if you do.

package main

import (
	"bufio"
	"log"
	"os"

	"github.com/mikaa123/imapmq"
)

func main() {
	// Create a new IMAPMQ client
	mq, err := imapmq.New(imapmq.Config{
		Login: "login",
		Passwd: "password",
		URL: "imap.gmail.com",
	})
	if err != nil {
		log.Panic(err)
	}
	defer mq.Close()

	// Create a queue based on INBOX
	q, err := mq.Queue("INBOX")
	if err != nil {
		log.Panic(err)
	}

	go func() {
		// Subscribe to messages with the "chat" subject
		c := q.Sub("chat")
		for msg := range c { // msg is a mail.Message instance.
			log.Printf("%s", msg.Header.Get("Subject"))
		}
	}()

	// We scan stdin for user input
	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		// Publish a message with the "chat" subject in the INBOX queue
		q.Pub("chat", []byte(scanner.Text()))
	}
}

Documentation

https://godoc.org/github.com/mikaa123/imapmq

License

MIT © Michael Sokol