server3.go

// Global variables for db connection , collection and context
var db *mongo.Client
var blogdb *mongo.Collection
var mongoCtx context.Context

func main {
  // STEP 1 & STEP 2 
  // STEP 3 (gRPC server)
  // ... 
  
  // Initialize MongoDb client
	fmt.Println("Connecting to MongoDB...")
  
  // non-nil empty context 
	mongoCtx = context.Background()
  
  // Connect takes in a context and options, the connection URI is the only option we pass for now
	db, err = mongo.Connect(mongoCtx, options.Client().ApplyURI("mongodb://localhost:27017"))
  // Handle potential errors
	if err != nil {
		log.Fatal(err)
	}
  
  // Check whether the connection was succesful by pinging the MongoDB server
	err = db.Ping(mongoCtx, nil)
	if err != nil {
		log.Fatalf("Could not connect to MongoDB: %v\n", err)
	} else {
		fmt.Println("Connected to Mongodb")
	}
  
  // Bind our collection to our global variable for use in other methods
	blogdb = db.Database("mydb").Collection("blog")
}