Custom role creation in MongoDB

Introduction

Custom roles let you control exactly what actions users can do in your database. This helps keep your data safe and organized.

You want to give a user permission to read data but not change it.

You need a user to manage only certain collections, not the whole database.

You want to limit a user's ability to create or delete data.

You want to create a role for a specific job, like reporting or backups.

You want to follow security rules by giving minimum needed access.

Syntax

MongoDB

db.createRole({
  role: "roleName",
  privileges: [
    {
      resource: { db: "databaseName", collection: "collectionName" },
      actions: ["action1", "action2"]
    }
  ],
  roles: []
})

role: The name of your new role.

privileges: What the role can do and where.

Examples

This role lets users only read data from the 'orders' collection in the 'sales' database.

MongoDB

db.createRole({
  role: "readOnly",
  privileges: [
    {
      resource: { db: "sales", collection: "orders" },
      actions: ["find"]
    }
  ],
  roles: []
})

This role allows full control over the 'orders' collection.

MongoDB

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

This role allows the user to read data from all collections in all databases.

MongoDB

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

Sample Program

This creates a role named 'reportViewer' that can only read data from the 'reports' collection in the 'companyDB' database.

MongoDB

db.createRole({
  role: "reportViewer",
  privileges: [
    {
      resource: { db: "companyDB", collection: "reports" },
      actions: ["find"]
    }
  ],
  roles: []
})

Important Notes

You must have the 'userAdmin' or 'userAdminAnyDatabase' role to create custom roles.

Use specific actions like 'find', 'insert', 'update', 'remove' to control permissions.

Roles can include other roles by listing them in the 'roles' array for easier management.

Summary

Custom roles let you give users only the permissions they need.

You define roles by naming them and listing what actions they can do on which data.

Creating roles helps keep your database secure and organized.

Practice

1. What is the main purpose of creating a custom role in MongoDB?

easy

A. To speed up database queries

B. To assign specific permissions tailored to user needs

C. To backup the database automatically

D. To create new collections in the database

Solution

1. Step 1: Understand role purpose

   Custom roles are designed to control what actions a user can perform.

2. Step 2: Match purpose to options

   Only To assign specific permissions tailored to user needs describes assigning specific permissions tailored to user needs.

3. Final Answer:

   To assign specific permissions tailored to user needs -> Option B

4. Quick Check:

   Custom role purpose = Assign specific permissions [OK]

Hint: Custom roles control user permissions precisely [OK]

Common Mistakes:

• Confusing roles with database backups
• Thinking roles speed up queries
• Assuming roles create collections

2. Which of the following is the correct syntax to create a custom role named readWriteReports with read and write privileges on the reports database?

easy

A. db.createRole({role: "readWriteReports", privileges: [{resource: {db: "reports"}, actions: ["readWrite"]}], roles: []})

B. db.createRole({role: "readWriteReports", privileges: [{resource: {db: "reports", collection: ""}, actions: ["find", "insert", "update"]}], roles: []})

C. db.createRole({name: "readWriteReports", privileges: [{resource: {db: "reports", collection: ""}, actions: ["find", "insert", "update"]}], roles: []})

D. db.createRole({name: "readWriteReports", privileges: [{resource: {db: "reports"}, actions: ["readWrite"]}], roles: []})

Solution

1. Step 1: Check correct field names

   The field for role name is name, not role.

2. Step 2: Verify privileges structure

   Privileges must specify resource with db and collection, and actions as an array of strings.

3. Final Answer:

   db.createRole({name: "readWriteReports", privileges: [{resource: {db: "reports", collection: ""}, actions: ["find", "insert", "update"]}], roles: []}) -> Option C

4. Quick Check:

   Use 'name' for role name and specify privileges correctly [OK]

Hint: Use 'name' key for role name in createRole [OK]

Common Mistakes:

• Using 'role' instead of 'name' for role name
• Omitting collection field in resource
• Using 'readWrite' as action instead of specific actions

3. Given the following command, what will be the effect of the custom role limitedUser?

db.createRole({
  name: "limitedUser",
  privileges: [
    { resource: { db: "sales", collection: "orders" }, actions: ["find"] }
  ],
  roles: []
})

medium

A. User has no permissions on sales.orders collection

B. User can read and write on sales.orders collection

C. User can perform any action on sales database

D. User can only read documents from sales.orders collection

Solution

1. Step 1: Analyze privileges actions

   The action specified is only "find", which means read access.

2. Step 2: Understand resource scope

   The resource is the "orders" collection in the "sales" database, so permissions apply only there.

3. Final Answer:

   User can only read documents from sales.orders collection -> Option D

4. Quick Check:

   Action 'find' = read only on specified collection [OK]

Hint: Action 'find' means read-only permission [OK]

Common Mistakes:

• Assuming 'find' allows write operations
• Thinking permissions apply to whole database
• Confusing empty roles array as full access

4. Identify the error in this custom role creation command:

db.createRole({
  name: "dataEditor",
  privileges: [
    { resource: { db: "analytics", collection: "reports" }, actions: "update" }
  ],
  roles: []
})

medium

A. The 'actions' field should be an array, not a string

B. The 'resource' field is missing the database name

C. The 'name' field should be 'role'

D. The 'roles' array cannot be empty

Solution

1. Step 1: Check 'actions' field type

   The 'actions' field must be an array of strings, but here it is a single string "update".

2. Step 2: Verify other fields

   The 'resource' includes both db and collection correctly; 'name' is correct; 'roles' can be empty.

3. Final Answer:

   The 'actions' field should be an array, not a string -> Option A

4. Quick Check:

   'actions' must be an array [OK]

Hint: Always use array for 'actions' even if one action [OK]

Common Mistakes:

• Using string instead of array for 'actions'
• Confusing 'name' with 'role' field
• Thinking 'roles' array cannot be empty

5. You want to create a custom role reportManager that allows users to read all collections in the reports database and also run the aggregate action on the summary collection only. Which of the following commands correctly implements this?

hard

A. db.createRole({name: "reportManager", privileges: [{resource: {db: "reports", collection: ""}, actions: ["find"]}, {resource: {db: "reports", collection: "summary"}, actions: ["aggregate"]}], roles: []})

B. db.createRole({name: "reportManager", privileges: [{resource: {db: "reports"}, actions: ["find"]}, {resource: {db: "reports", collection: "summary"}, actions: ["aggregate"]}], roles: []})

C. db.createRole({name: "reportManager", privileges: [{resource: {db: "reports", collection: "summary"}, actions: ["find", "aggregate"]}], roles: []})

D. db.createRole({name: "reportManager", privileges: [{resource: {db: "reports", collection: ""}, actions: ["find", "aggregate"]}], roles: []})

Solution

1. Step 1: Understand the requirements

   Users must have read (find) access on all collections in 'reports' and aggregate only on 'summary' collection.

2. Step 2: Check privileges for all collections

   Using collection: "" means all collections in the database, so first privilege grants find on all collections.

3. Step 3: Check aggregate privilege on summary

   Second privilege grants aggregate only on 'summary' collection.

4. Final Answer:

   db.createRole({name: "reportManager", privileges: [{resource: {db: "reports", collection: ""}, actions: ["find"]}, {resource: {db: "reports", collection: "summary"}, actions: ["aggregate"]}], roles: []}) -> Option A

5. Quick Check:

   Separate privileges for all collections and specific collection actions [OK]

Hint: Use empty string for all collections, specify collection for specific actions [OK]

Common Mistakes:

• Using db only without collection for find
• Combining find and aggregate on all collections
• Missing separate privilege for aggregate on summary