Add ability to supply Mongo connection uri

mongodb/mongodb.go

@@ -33,26 +33,33 @@ func New(config ...Config) *Storage {
 	cfg := configDefault(config...)
 
 	// Create data source name
-	var dsn = "mongodb"
-	if cfg.Atlas {
-		dsn += "+srv://"
+	var dsn string
+
+	// Check if user supplied connection string
+	if cfg.Connection != "" {
+		dsn = cfg.Connection
 	} else {
-		dsn += "://"
-	}
-	if cfg.Username != "" {
-		dsn += url.QueryEscape(cfg.Username)
-	}
-	if cfg.Password != "" {
-		dsn += ":" + cfg.Password
-	}
-	if cfg.Username != "" || cfg.Password != "" {
-		dsn += "@"
-	}
-	// Cannot specify port when using MongoDB Atlas
-	if cfg.Atlas {
-		dsn += url.QueryEscape(cfg.Host)
-	} else {
-		dsn += fmt.Sprintf("%s:%d", url.QueryEscape(cfg.Host), cfg.Port)
+		dsn = "mongodb"
+		if cfg.Atlas {
+			dsn += "+srv://"
+		} else {
+			dsn += "://"
+		}
+		if cfg.Username != "" {
+			dsn += url.QueryEscape(cfg.Username)
+		}
+		if cfg.Password != "" {
+			dsn += ":" + cfg.Password
+		}
+		if cfg.Username != "" || cfg.Password != "" {
+			dsn += "@"
+		}
+		// Cannot specify port when using MongoDB Atlas
+		if cfg.Atlas {
+			dsn += url.QueryEscape(cfg.Host)
+		} else {
+			dsn += fmt.Sprintf("%s:%d", url.QueryEscape(cfg.Host), cfg.Port)
+		}
 	}
 
 	// Set mongo options