mongodb

MongoDB Driver for ncore/data

This package provides a MongoDB driver implementation for the ncore/data framework.

Installation

go get github.com/ncobase/ncore/data/mongodb

Usage

Import the driver in your application to register it automatically:

import (
    "context"
    "github.com/ncobase/ncore/data"
    "github.com/ncobase/ncore/data/config"
    _ "github.com/ncobase/ncore/data/mongodb" // Register MongoDB driver
)

func main() {
    // Get the MongoDB driver
    driver, err := data.GetDatabaseDriver("mongodb")
    if err != nil {
        panic(err)
    }

    // Configure MongoDB connection
    cfg := &config.MongoDB{
        Master: &config.MongoNode{
            URI: "mongodb://localhost:27017/mydb",
        },
        Slaves: []*config.MongoNode{
            {
                URI: "mongodb://slave1:27017/mydb",
                Weight: 2,
            },
        },
        Strategy: "round_robin",
        MaxRetry: 3,
    }

    // Connect to MongoDB
    ctx := context.Background()
    conn, err := driver.Connect(ctx, cfg)
    if err != nil {
        panic(err)
    }
    defer driver.Close(conn)

    // Use the connection (conn is *mongo.Client)
    client := conn.(*mongo.Client)
    db := client.Database("mydb")
    // ... perform operations
}

Configuration

The driver expects a *config.MongoDB configuration struct with the following fields:

Master (required)

The primary MongoDB node configuration:

Master: &config.MongoNode{
    URI:     "mongodb://localhost:27017/mydb",  // MongoDB connection URI
    Logging: true,                              // Enable logging (optional)
    Weight:  1,                                 // Weight for load balancing (optional)
}

Slaves (optional)

Slave nodes for read operations:

Slaves: []*config.MongoNode{
    {
        URI:    "mongodb://slave1:27017/mydb",
        Weight: 2,
    },
    {
        URI:    "mongodb://slave2:27017/mydb",
        Weight: 1,
    },
}

Strategy (optional)

Load balancing strategy for slave nodes:

• round_robin (default): Distributes requests evenly across slaves
• random: Randomly selects a slave for each request
• weight: Distributes requests based on node weights

MaxRetry (optional)

Maximum number of retry attempts for failed operations.

MongoDB URI Format

The MongoDB URI follows the standard MongoDB connection string format:

mongodb://[username:password@]host1[:port1][,...hostN[:portN]][/[defaultauthdb][?options]]
mongodb+srv://[username:password@]host[/[defaultauthdb][?options]]

Examples

Local development:

mongodb://localhost:27017/mydb

With authentication:

mongodb://user:password@localhost:27017/mydb?authSource=admin

MongoDB Atlas (cloud):

mongodb+srv://user:password@cluster.mongodb.net/mydb

Replica set:

mongodb://host1:27017,host2:27017,host3:27017/mydb?replicaSet=myrs

Features

• ✅ Implements data.DatabaseDriver interface
• ✅ Returns *mongo.Client for full MongoDB functionality
• ✅ Automatic connection verification (ping on connect)
• ✅ Proper context handling for all operations
• ✅ Support for MongoDB connection options via URI
• ✅ Master/slave configuration support
• ✅ Multiple load balancing strategies
• ✅ Connection pooling (configured via URI options)

Driver Methods

Name() string

Returns the driver identifier: "mongodb"

Connect(ctx context.Context, cfg interface{}) (interface{}, error)

Establishes a MongoDB connection using the provided *config.MongoDB configuration. Returns a *mongo.Client on success.

Close(conn interface{}) error

Closes the MongoDB connection and releases resources.

Ping(ctx context.Context, conn interface{}) error

Verifies the MongoDB connection is alive and functional.

Error Handling

The driver provides detailed error messages for common issues:

• Invalid configuration type
• Missing master configuration
• Empty URI
• Connection failures
• Ping failures
• Invalid connection type

All errors are wrapped with context using fmt.Errorf and %w for proper error chain support.

Testing

Run the test suite:

cd data/mongodb
go test -v

See Also

• MongoDB Go Driver Documentation
• ncore/data Package
• MongoDB Connection String Documentation