Boilerplate for a stream API in go

megatron.go

package main

import (
	"fmt"
	"github.com/codegangsta/martini-contrib/binding"
	"github.com/go-martini/martini"
	"gopkg.in/mgo.v2"
	"gopkg.in/mgo.v2/bson"
	"net/http"
)

// Using this over mgo.DBRef because it wouldn't coerce JSON correctly
type EventRef struct {
	Id   bson.ObjectId `bson:"$id" json:"$id"`
	Type string        `bson:"$ref" json:"$ref"`
}

type Stream struct {
	Id       bson.ObjectId `bson:"_id"`
	Type     string        `bson:"_type" json:"_type"`
	Events   []EventRef
	DeviceId string `bson:"device_id" json:"device_id"`
}

func main() {
	session, err := mgo.Dial("localhost:27017")
	if err != nil {
		panic(err)
	}
	defer session.Close()

	m := martini.Classic()
	m.Map(session)

	m.Post("/stream/(?P<id>\\w{24})", binding.Json(Stream{}), func(newStream Stream, params martini.Params, session *mgo.Session) {
		streamId := bson.ObjectIdHex(params["id"])

		var oldStream Stream
		streams := session.DB("streams").C("stream")
		err := streams.Find(bson.M{"_id": streamId}).One(&oldStream)
		if err == nil {
			fmt.Println("Handling pre-existing stream")

			// These should look identical if your POST JSON matches the saved record
			fmt.Println(newStream)
			fmt.Println(oldStream)
		} else if err == mgo.ErrNotFound {
			fmt.Println("Handling brand new stream")
		} else {
			panic(err)
		}
	})

	http.ListenAndServe(":8011", m)
}