creating-clients.md

Creating Clients

Our MongoDB driver offers great flexibility to support various use cases. You can create multiple clients for different clusters, users, or operations, which can greatly increase productivity and security.

To create a client, pass an options object to the createClient method. The connection property is required, while the rest of the options are optional.

Client Configuration Options

Property	Required	Description
name	✅	Specify the connection name. Read More.
authorization	❌	Set the authorization level for the client. System or User. Default: User.
defaultDatabase	❌	If not defined here, you'll need to specify it for each CRUD operation.
user	❌	Set the user details when the authorization level is User.

const client = mongodb.createClient({ name: 'LocalServer' });

// OR
const client = mongodb.createClient({
    name: mongodb.defineConnection('LocalServer', 'mongodb://localhost:27017')
});

---

Default Database

You can specify the default database that your client will connect to via the defaultDatabase option. If not specified, you'll need to define the database for each CRUD operation.

const systemClient = mongodb.createClient({
    name: 'localServer', // A name of a defined connection
    defaultDatabase: '<database_name>'
});

__

Permissions & Authorizations

The MongoDB driver supports two levels of authorization:

• System Authorization: The System authorization level bypasses any permissions your collections might have. This is typically used for system-level operations.

  /**A client that does NOT do user-related operations */
  const systemClient = mongodb.createClient({
      name: 'localServer', // A name of a defined connection
      authorization: 'System'
  });

• User Authorization: The User authorization level is meant for user-specific operations. The MongoDB client will automatically enforce collection-level permissions based on the user's role.

  router.patch('/users/<:userId>', async (request, response, next) => {
      try {
          const { userId } = request.params;
          if (!request.user.loggedIn || request.user.id !== userId) { return response.pages.unauthorized() }
  
          const dbClient = mongodb.createClient({
              name: 'localServer', // A name of a defined connection
              authorization: 'User',
              user: {
                  id: request.user.id,
                  role: request.user.role,
                  loggedIn: request.user.loggedIn
              }
          });
  
          // Safely run operations on any collection
          const user = await dbClient.getItem('Members', userId);
      } catch(error) {
          console.error(error);
          response.status(500).json({ message: 'Unable to update the user due to a server error' });
      }
  })

  In the example above:

  • The User authorization level ensures that only users with the correct permissions can access or modify data.
  • If the user doesn't have read permission on the collection or the requested resource, the getItem operation will be rejected.
  
  By dynamically defining a database client based on user data, you can ensure that all permissions and roles are enforced. Unauthorized users cannot bypass these permissions, providing a robust security mechanism. When creating the client, integrating user-specific data such as ID, role, and login status ensures that operations are securely performed within the user’s permissions.
  
  

  [!TIP] When performing a read operation using a client with User authorization, only records owned by the current user (i.e., where the _owner field matches the user ID) will be fetched.