CORS configuration in AWS - Mini Project: Build & Apply

Configure CORS for an AWS S3 Bucket

📖 Scenario: You are setting up a static website hosted on an AWS S3 bucket. To allow your website to request resources from this bucket securely, you need to configure Cross-Origin Resource Sharing (CORS) rules.

🎯 Goal: Configure CORS rules on an AWS S3 bucket to allow GET requests from a specific origin.

📋 What You'll Learn

Create a CORS configuration JSON with one rule

Allow GET method only

Allow origin 'https://example.com'

Allow all headers

Set max age to 3000 seconds

💡 Why This Matters

🌍 Real World

Configuring CORS is essential when hosting static websites or APIs on AWS S3 to control which websites can access your resources.

💼 Career

Cloud engineers and DevOps professionals often configure CORS to secure web applications and enable cross-origin requests safely.

1

Create the initial CORS configuration structure

Create a variable called cors_configuration and assign it a dictionary with a key CORSRules that holds an empty list.

AWS

cors_configuration = {
    "CORSRules": []
}
# Your code here

Need a hint?

Start by creating a dictionary with the key 'CORSRules' set to an empty list.

2

Add a CORS rule dictionary

Add a dictionary inside the CORSRules list in cors_configuration. This dictionary should have keys AllowedMethods, AllowedOrigins, AllowedHeaders, and MaxAgeSeconds with empty or zero values.

AWS

cors_configuration = {
    "CORSRules": [
        {
            "AllowedMethods": [],
            "AllowedOrigins": [],
            "AllowedHeaders": [],
            "MaxAgeSeconds": 0
        }
    ]
}
# Your code here

Need a hint?

Add a dictionary with the required keys inside the 'CORSRules' list.

3

Configure the CORS rule with specific values

Set the AllowedMethods to a list containing "GET", AllowedOrigins to a list containing "https://example.com", AllowedHeaders to a list containing "*", and MaxAgeSeconds to 3000 inside the first dictionary in CORSRules.

AWS

cors_configuration = {
    "CORSRules": [
        {
            "AllowedMethods": ["GET"],
            "AllowedOrigins": ["https://example.com"],
            "AllowedHeaders": ["*"],
            "MaxAgeSeconds": 3000
        }
    ]
}
# Your code here

Need a hint?

Fill in the lists and number with the exact values to allow GET from the example.com origin.

4

Complete the AWS CLI command to apply the CORS configuration

Write the AWS CLI command string called apply_cors_command that uses aws s3api put-bucket-cors with the bucket name my-static-site-bucket and the CORS configuration file cors.json.

AWS

cors_configuration = {
    "CORSRules": [
        {
            "AllowedMethods": ["GET"],
            "AllowedOrigins": ["https://example.com"],
            "AllowedHeaders": ["*"],
            "MaxAgeSeconds": 3000
        }
    ]
}
apply_cors_command = "aws s3api put-bucket-cors --bucket my-static-site-bucket --cors-configuration file://cors.json"
# Your code here

Need a hint?

Write the exact AWS CLI command string to apply the CORS configuration from the file.