Introduction

In this tutorial, you will learn how to implement Role-Based Access Control (RBAC) in MongoDB. Role-Based Access Control is a method that handles user permissions based on the roles assigned to the users. This method is crucial for managing access to resources in a database.

By the end of this tutorial, you will be able to:

• Understand the concept of RBAC
• Create roles in MongoDB
• Assign roles to users
• Implement access control based on roles

Prerequisites

• Basic understanding of MongoDB and its database operations
• MongoDB installed on your local machine

Step-by-Step Guide

What is RBAC (Role-Based Access Control)?

In RBAC, permissions are associated with roles, and users are made members of roles thereby acquiring the roles' permissions. The user-role and permission-role relationships make it simple to perform user assignments since users no longer need to be managed individually, but instead, they are grouped based on roles.

Creating Roles in MongoDB

In MongoDB, you can create roles using the db.createRole() method. This method requires a document that specifies the role, the privileges, and the roles the new role inherits.

Here is how to create a role:

db.createRole(
   {
     role: "readWriteRole",
     privileges: [
       { resource: { db: "test", collection: "" }, actions: [ "find","insert","remove","update" ] }
     ],
     roles: []
   }
)

Assigning Roles to Users

After creating roles, you can assign them to users using the db.createUser() method in MongoDB.

Here is how to assign a role to a user:

db.createUser(
  {
    user: "myUser",
    pwd: "myUserPassword",
    roles: [ { role: "readWriteRole", db: "test" } ]
  }
)

Code Examples

Example 1: Creating a Role

Below is a practical example of creating a role in MongoDB:

db.createRole(
   {
     role: "readRole",
     privileges: [
       { resource: { db: "myDatabase", collection: "" }, actions: [ "find" ] }
     ],
     roles: []
   }
)

In the code above:

• role: This is the name of the role. In this case, the name is "readRole".
• privileges: This is an array of privilege documents that specify the permissions of the role. In this case, the privilege is the "find" action on the "myDatabase" database.
• roles: This is an array of existing roles from which the new role inherits privileges.

Example 2: Assigning a Role to a User

Below is a practical example of assigning a role to a user:

db.createUser(
  {
    user: "myUser",
    pwd: "myUserPassword",
    roles: [ { role: "readRole", db: "myDatabase" } ]
  }
)

In the code above:

• user: This is the username. In this case, the username is "myUser".
• pwd: This is the password for the user. In this case, the password is "myUserPassword".
• roles: This is an array of roles to assign to the user. In this case, the "readRole" is assigned to the user.

Summary

In this tutorial, you learned how to implement RBAC in MongoDB. You learned how to create roles, assign roles to users, and manage user permissions based on roles. The next step would be to understand how to manage and update roles and user permissions effectively.

Practice Exercises

Exercise 1
Create a 'writeRole' with privileges to insert and update data in a collection called 'myCollection' in the 'myDatabase' database.

Exercise 2
Create a user 'myAdmin' with password 'myAdminPassword', and assign the 'writeRole' and 'readRole' to the user.

Exercise 3
Create a 'superRole' that inherits all the privileges of 'readRole' and 'writeRole', and assign it to a new user 'superUser'.

Solutions
1. To create 'writeRole':

db.createRole(
   {
     role: "writeRole",
     privileges: [
       { resource: { db: "myDatabase", collection: "myCollection" }, actions: [ "insert","update" ] }
     ],
     roles: []
   }
)

1. To create 'myAdmin' user:

db.createUser(
  {
    user: "myAdmin",
    pwd: "myAdminPassword",
    roles: [ { role: "readRole", db: "myDatabase" }, { role: "writeRole", db: "myDatabase" } ]
  }
)

1. To create 'superRole' and assign it to 'superUser':

// Create superRole
db.createRole(
   {
     role: "superRole",
     privileges: [],
     roles: [ { role: "readRole", db: "myDatabase" }, { role: "writeRole", db: "myDatabase" } ]
   }
)

// Create superUser
db.createUser(
  {
    user: "superUser",
    pwd: "superUserPassword",
    roles: [ { role: "superRole", db: "myDatabase" } ]
  }
)

Remember to test your code after each step and ensure you understand each operation. Happy coding!