Managing Firestore Security Rules

1. Introduction

Firestore is a flexible, scalable database for mobile, web, and server development from Firebase and Google Cloud. Firestore Security Rules are essential to secure your data. In this tutorial, we will learn how to manage Firestore Security Rules.

What You Will Learn

• Understand Firestore Security Rules
• Write and Update Firestore Security Rules
• Test Firestore Security Rules

Prerequisites

• Basic knowledge of Firestore
• Firebase project setup on Google Cloud

2. Step-by-Step Guide

Firestore Security Rules are written in a custom, JSON-like language. These rules are used to determine who has read and write access to your Firestore database, how documents are structured and what indexes exist.

Writing Firestore Security Rules

You can write Firestore Security Rules in the Firebase console. Here's an example of how a rule looks like:

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if false;
    }
  }
}

This rule simply denies all read and write operations.

Updating Firestore Security Rules

You can update Firestore Security Rules from Firebase Console. Navigate to the "Database" section, select the "Rules" tab, and update your rules.

Testing Firestore Security Rules

To test Firestore Security Rules, you can use the Firestore rules simulator in the Firebase console. This allows you to simulate read, write, and delete operations.

3. Code Examples

Example 1: Allow all users to read, but only authenticated users to write

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read: if true;
      allow write: if request.auth.uid != null;
    }
  }
}

In this example, allow read: if true; allows all users to read the data. allow write: if request.auth.uid != null; allows only authenticated users to write the data.

Example 2: Allow users to read and write their own data

service cloud.firestore {
  match /databases/{database}/documents {
    match /users/{userId} {
      allow read, write: if request.auth.uid == userId;
    }
  }
}

In this example, allow read, write: if request.auth.uid == userId; allows users to read and write only their own data.

4. Summary

In this tutorial, we learned what Firestore Security Rules are, how to write, update, and test these rules.

Next Steps for Learning

• Learn more about complex Firestore Security Rules.
• Learn how to test Firestore Security Rules with the Firebase Emulator Suite.

Additional Resources

• Firestore Security Rules documentation
• Firestore Security Rules samples

5. Practice Exercises

Exercise 1: Write a rule that allows only the creator to read and write a document

service cloud.firestore {
  match /databases/{database}/documents {
    match /documents/{docId} {
      allow read, write: if request.auth.uid == resource.data.creator;
    }
  }
}

In this rule, only the creator of the document, whose user ID is stored in the creator field, can read and write the document.

Exercise 2: Write a rule that allows anyone to read, but only users with an email verified to write

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read: if true;
      allow write: if request.auth.token.email_verified;
    }
  }
}

In this rule, allow read: if true; allows anyone to read the documents, and allow write: if request.auth.token.email_verified; allows only users with a verified email to write.