gistfile1.txt

package main

import (
	"crypto/tls"
	"log"
)

type OpCode int32

const MsgHeaderLen = 16

// SetInt32 sets the 32-bit int into the given byte array at position post
// Taken from gopkg.in/mgo.v2/socket.go
func SetInt32(b []byte, pos int, i int32) {
	b[pos] = byte(i)
	b[pos+1] = byte(i >> 8)
	b[pos+2] = byte(i >> 16)
	b[pos+3] = byte(i >> 24)
}

func main() {
	log.SetFlags(log.Lshortfile)

	conf := &tls.Config{
		InsecureSkipVerify: true,
	}

	//mongodb://user:<PASSWORD>@cluster0-shard-00-00-f4rbl.mongodb-qa.net:27017,cluster0-shard-00-01-f4rbl.mongodb-qa.net:27017,cluster0-shard-00-02-f4rbl.mongodb-qa.net:27017/<DATABASE>?ssl=true&replicaSet=Cluster0-shard-0&authSource=admin
	conn, err := tls.Dial("tcp", "localhost:9900", conf)
	if err != nil {
		log.Println(err)
		return
	}
	defer conn.Close()

	ms := MsgHeader{
		OpCode:        2011,
		RequestID:     1000,
		ResponseTo:    999,
		MessageLength: 10,
	}

	n, err := conn.Write(ms.ToWire())
	if err != nil {
		log.Println(n, err)
		return
	}

	buf := make([]byte, 100)
	n, err = conn.Read(buf)
	if err != nil {
		log.Println(n, err)
		return
	}

}

// MsgHeader is the mongo MessageHeader
type MsgHeader struct {
	// MessageLength is the total message size, including this header
	MessageLength int32
	// RequestID is the identifier for this miessage
	RequestID int32
	// ResponseTo is the RequestID of the message being responded to;
	// used in DB responses
	ResponseTo int32
	// OpCode is the request type, see consts above.
	OpCode OpCode
}

// ToWire converts the MsgHeader to the wire protocol
func (m MsgHeader) ToWire() []byte {
	var d [MsgHeaderLen]byte
	b := d[:]
	SetInt32(b, 0, m.MessageLength)
	SetInt32(b, 4, m.RequestID)
	SetInt32(b, 8, m.ResponseTo)
	SetInt32(b, 12, int32(m.OpCode))
	return b
}