Oplog

MongoDB replicaset oplog tailing by Golang

Tailing of MongoDB Oplog

It can be send oplog to everywhere with minimal system resource usage.

• MongoDB replicaset -> Oplog -> MongoDB | Logstash | Fluentd | ...

Install

go get -u github.com/gnokoheat/oplog

Usage example

• main.go

package main

import (
	"log"
	"github.com/gnokoheat/oplog"
)

func main() {
	var o = &oplog.Options{
		// (e.g. mongodb://username:[email protected]:27017,127.0.0.1:27018/local?replicaSet=rs01&authSource=admin)
		Addrs:      []string{"127.0.0.1:27017", "127.0.0.1:27018"}, // replicaset host and port
		Username:   "username", // admin db username
		Password:   "password", // admin db user password
		ReplicaSet: "rs01", // replicaset name
		DB:         "myDB", // tailing target db
		Collection: "myCollection", // tailing target collection
		Events:     []string{"insert", "update", "delete"}, // tailing target method
	}

	l := make(chan *[]oplog.Log) // Oplog Channel
	e := make(chan error) // Error Channel
	
	// Oplog tailing start ! 
	go o.Tail(l, e)

	for {
		select {
		case err := <-e:
			log.Println("[Error] ", err)
			return
		case op := <-l:
			// input oplog handling code
			log.Println("[Result] ", op)
			break
		}
	}
}

• Run

go run main.go

• Result

2019/11/08 16:13:57 [Oplog Tail Start]  2019-11-08 07:13:57.485633 +0000 UTC
2019/11/08 16:14:04 [Result]  &[{2019-11-08 16:14:02.744 +0900 ... ]
2019/11/08 16:14:08 [Result]  &[{2019-11-08 16:14:08.554 +0900 ... ]
2019/11/08 16:16:57 [Result]  &[{2019-11-08 16:16:57.364 +0900 ... ]
...