Custom role creation in MongoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a custom role in MongoDB?

A custom role in MongoDB is a user-defined set of privileges that control access to database actions, allowing fine-tuned permission management beyond built-in roles.

beginner

Which command is used to create a custom role in MongoDB?

The db.createRole() command is used to create a custom role in MongoDB.

intermediate

What are the main components you must specify when creating a custom role?

You must specify the role name, privileges (actions and resources), and optionally roles to inherit from other roles.

intermediate

How do you assign a custom role to a user in MongoDB?

Use the db.grantRolesToUser() command to assign a custom role to a user.

intermediate

Can a custom role inherit privileges from built-in roles in MongoDB?

Yes, a custom role can inherit privileges by including built-in roles in its roles array during creation.

Which MongoDB command creates a custom role?

A db.createUser()

B db.addRole()

C db.createRole()

D db.grantRolesToUser()

The db.createRole() command is specifically used to create custom roles.

What must you specify when defining privileges for a custom role?

A Database size

B Actions and resources

C Only user names

D Network settings

Privileges require specifying the actions allowed and the resources those actions apply to.

How do you assign a custom role to a user?

A db.grantRolesToUser()

B db.createRole()

C db.createUser()

D db.assignRole()

The db.grantRolesToUser() command assigns roles, including custom roles, to users.

Can a custom role include other roles?

A Only user roles can be included

B No, roles are always standalone

C Only built-in roles can be included

D Yes, it can inherit other roles

Custom roles can inherit privileges by including other roles in their definition.

Which of these is NOT a valid privilege action in MongoDB custom roles?

A compile

B insert

C delete

D find

Actions like find, insert, and delete are valid; compile is not a MongoDB privilege action.

Explain how to create a custom role in MongoDB and what key parts you need to define.

Think about the command and the structure of the role document.

Describe the process to assign a custom role to a user in MongoDB.

Focus on the command that links roles to users.

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