How to set bucket CORS configuration

Estimated time to read: 2 minutes

Learn how to set CORS configuration on containers and buckets in the Fuga Object Store

CORS according to boto3.amazonaws.com:

Cross Origin Resource Sharing (CORS) enables client web applications in one domain to access resources in another domain. An S3 bucket can be configured to enable cross-origin requests. The configuration defines rules that specify the allowed origins, HTTP methods (GET, PUT, etc.), and other elements.

Prerequisites:

• Fuga Cloud EC2 credentials
• Python 3.6+
• boto3 python package (tested with boto3 1.9.244 and botocore 1.12.244)

Create a new Python file named add-cors-configuration.py with the following content:

#!/usr/bin/env python3

import os
import sys
import json
from argparse import ArgumentParser
from urllib.parse import urlencode, quote_plus

import boto3

with open('credentials.json', 'r') as fd:
    credentials = json.loads(fd.read())

def main():

    parser = ArgumentParser(description='set bucket CORS configuration')
    parser.add_argument('--bucket-name',
                        dest='bucket_name',
                        action='store',
                        required=True,
                        help='name of the bucket')
    parser.add_argument('--cors-config',
                        dest='cors_config_path',
                        action='store',
                        required=True,
                        help='path to CORS configuration')
    args = parser.parse_args()

    s3 = boto3.client('s3',
        endpoint_url=credentials.get('endpoint_url'),
        aws_access_key_id=credentials.get('access_key'),
        aws_secret_access_key=credentials.get('secret_key'),
    )

    with open(args.cors_config_path, 'r') as fd:
        cors_configuration = json.loads(fd.read())

    response = s3.put_bucket_cors(Bucket=args.bucket_name,
       CORSConfiguration=cors_configuration)

    response = s3.get_bucket_cors(Bucket=args.bucket_name)
    print(json.dumps(response['CORSRules'], indent=2))


if __name__ == '__main__':
    main()

Create a new JSON file named cors.json with the following content, update the contents to match your setup:

{
  "CORSRules": [
    {
      "AllowedHeaders": [
        "Authorization"
      ],
      "AllowedMethods": [
        "GET",
        "PUT"
      ],
      "AllowedOrigins": [
        "*"
      ],
      "ExposeHeaders": [
        "GET",
        "PUT"
      ],
      "MaxAgeSeconds": 3000
    }
  ]
}

Create a new JSON file named credentials.json with the following content, update the contents to match your setup, you can find the endpoints in Fuga Cloud dashboard.

{
  "access_key": "<your ec2 credential access>",
  "secret_key": "<your ec2 credential secret>",
  "endpoint_url": "<api_endpoints>"
}

Install required Python packages and run the script to set CORS configuration:

% pip install --user boto3
% python3.7 ./add_cors_configuration.py --bucket-name my-first-bucket --cors-config ./cors.json
{
  "CORSRules": [
    {
      "AllowedHeaders": [
        "Authorization"
      ],
      "AllowedMethods": [
        "GET",
        "PUT"
      ],
      "AllowedOrigins": [
        "*"
      ],
      "ExposeHeaders": [
        "GET",
        "PUT"
      ],
      "MaxAgeSeconds": 3000
    }
  ]
}

For information and examples see boto3.amazonaws.com.