Awesome

nigroni-mgo-session

nigroni-mgo-session is a simple Negroni middleware/handler for easy mgo session management in requests. It handles creating a new mongo session in the begning of a request and handles closing the mongo session at the end of request.

Getting Started

Before getting started make sure we have a copy of MongoDB running and is accessible. Running it locally would be recommended, but if thats not an option you can run on a remote server. Makes sure the mongo server is accessible, and you have a Mongo collection created within the database. If you haven't installed nigroni-mgo-session, you can run the below command to install it.
```
go get github.com/joeljames/nigroni-mgo-session
```
This package will be used with nigroni and mgo. If you haven't installed the dependencies you could install run the below command.
- To install Nigroni run the command below.
```
go get github.com/codegangsta/negroni
```
- To install mgo run the command below.
```
go get gopkg.in/mgo.v2
```

Now lets add an example which demonstrates the usage of this middleware. I have added comments to the example to explain the usage.

Now, that you have a running instance of MongoDB you can Shell into mongo by running the command below.
```
mongo
```

Create your database and collection and insert some data into the collection.

use db
db.createCollection("widget");
db.widget.insert({'id': '123'});
db.widget.insert({'id': '456'});

Set your DATABASE_URL and DATABASE_NAME environment variable.

export DATABASE_URL=mongodb://username:password@localhost:27017/db
export DATABASE_NAME=db

If you have the package and dependency downloaded, you could simple copy the above example to a file example.go and then run the command go run example.go to start up the server.

    package main

    import (
        "fmt"
        "net/http"
        "os"

        "github.com/codegangsta/negroni"
        nigronimgosession "github.com/joeljames/nigroni-mgo-session"
    )

    func main() {
        // Use the MongoDB `DATABASE_URL` from the env
        dbURL := os.Getenv("DATABASE_URL")
        // Use the MongoDB `DATABASE_NAME` from the env
        dbName := os.Getenv("DATABASE_NAME")
        // Set the MongoDB collection name
        dbColl := "widget"

        fmt.Println("Connecting to MongoDB: ", dbURL)
        fmt.Println("Database Name: ", dbName)
        fmt.Println("Collection Name: ", dbColl)

        // Creating the database accessor here.
        // Pointer to this database accessor will be passed to the middleware.
        dbAccessor, err := nigronimgosession.NewDatabaseAccessor(dbURL, dbName, dbColl)
        if err != nil {
            panic(err)
        }

        n := negroni.Classic()

        // Registering the middleware here.
        n.Use(nigronimgosession.NewDatabase(*dbAccessor).Middleware())

        mux := http.NewServeMux()
        mux.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) {
            // You can access the nms object from the request context.
            // The nms object is stored in key `nigronimgosession.KEY`.
            ctx := request.Context()
            nms := ctx.Value(nigronimgosession.KEY).(*nigronimgosession.NMS)
            // Now lets perform a count query using mgo db object.
            count, _ := nms.DB.C("widget").Find(nil).Count()

            fmt.Fprintf(writer, "Determining the count in the collection using the db object. \n\n")
            fmt.Fprintf(writer, "Total number of object in the mongo database: %d  \n\n", count)

            // You can access the mgo session object from the request object.
            // The session object is stored in key `mgoSession`.
            count2, _ := nms.Session.DB(dbName).C("widget").Find(nil).Count()
            fmt.Fprintf(writer, "Determining the count in the collection using the session object. \n\n")
            fmt.Fprintf(writer, "Total number of object in the mongo database: %d  \n\n", count2)
        })

        n.UseHandler(mux)
        n.Run(":3000")
    }

Assuming you are running the server locally, you can hit http://localhost:3000/ to see the output.

Contribution

Fork the package on Github

git clone https://github.com/joeljames/nigroni-mgo-session.git
cd nigroni-mgo-session

Create a new local branch to submit a pull request.
```
git checkout -b name-of-feature
```

Commit your changes

git commit -m "Detailed commit message"
git push origin name-of-feature

Submit a pull request.