Supermetal Documentation

Prerequisites

Before you begin, ensure you have:

MongoDB Requirements:
- Version: MongoDB 4.0 or higher (required for change streams support)
- Supported Deployments:
  - MongoDB Community/Enterprise Server (replica set configuration)
  - MongoDB Atlas
Change Streams Requirement
Change streams require a replica set deployment. If you're using a standalone server, you must convert it to a single-node replica set to use change streams.
Deployment Requirements:
- Replica Set: Your MongoDB deployment must be configured as a replica set
- Read Concern Majority: Supermetal uses read concern "majority" to ensure consistent reads
- Database Permissions: User with appropriate permissions (see Setup)
- Network Connectivity: Ensure Supermetal can reach your MongoDB deployment (default port: 27017)
- TLS/SSL Support: Supermetal supports both unencrypted and TLS/SSL encrypted connections
MongoDB Atlas Requirements:
- Network Access: Configure network access rules to allow Supermetal to connect
- Connection String: Use the connection string format that includes all replica set members

Setup

Permissions Overview

Supermetal requires a dedicated MongoDB user with appropriate permissions to read data and access change streams. The recommended approach is to create a dedicated read-only user.

MongoDB Deployment	Minimum Required Permissions
Self-managed	`read` role on the mongo database to replicate from
MongoDB Atlas	`readAnyDatabase` role

Create a Dedicated Read-Only MongoDB User

Connect to your MongoDB instance using the mongo shell with admin privileges:

mongosh --host <host> --port <port> -u <admin-username> -p <admin-password> --authenticationDatabase admin

Script Variables

Replace the placeholder values in the command with your actual information:

<host>: Your MongoDB server hostname or IP address
<port>: MongoDB port (default is 27017)
<admin-username>: Username with admin privileges
<admin-password>: Password for the admin user

Create a dedicated user for Supermetal:

use admin
db.createUser({
  user: "supermetal_user",
  pwd: "strong-password",
  roles: [
    { role: "read", db: "target-database" }
  ]
})

Script Variables

Replace the placeholder values in the script with your actual information:

strong-password: Replace with a secure, unique password for the supermetal_user.
target-database: The name of the database you want to replicate from.