How to Set public-read ACL for All Objects in an AWS S3 Bucket?

Ayyaz

@AyyazTech

How to Set public-read ACL for All Objects in an AWS S3 Bucket

In today's rapidly digitalising world, the use of cloud storage has skyrocketed. Amazon's Simple Storage Service (S3) is one of the most widely recognized storage services. There are times when you might need to modify the Access Control List (ACL) for every object in an S3 bucket. For example, you may want to make all the objects publicly readable for a web application. Here, we will walk through a simple, effective method to achieve this using the AWS Command Line Interface (CLI).

Pre-requisites:

• AWS CLI installed and configured.
• Appropriate permissions to list and modify S3 bucket objects.

Steps:

1- List All Objects in the Bucket:

Using the aws s3api list-objects command, you can fetch a list of all objects in the bucket.

aws s3api list-objects --bucket bucket-name --query 'Contents[].Key' --output text

aws s3api list-objects --bucket bucket-name --query 'Contents[].Key' --output text

2- Iterate Over Each Object and Set the ACL:

Once we have a list of all objects, we can loop through each one and modify its ACL.

for key in $(aws s3api list-objects --bucket bucket-name --query 'Contents[].Key' --output text)
do
  aws s3api put-object-acl --bucket bucket-name --key "$key" --acl public-read
done

for key in $(aws s3api list-objects --bucket bucket-name --query 'Contents[].Key' --output text)
do
  aws s3api put-object-acl --bucket bucket-name --key "$key" --acl public-read
done

3- Verify the Changes:

It's always a good practice to verify changes. You can manually check a few object URLs in your browser to ensure they are publicly accessible.

Tips:

Monitor the Cost: Making objects public can increase data transfer costs if they are accessed frequently. It's wise to monitor your AWS billing dashboard.

Avoid Unwanted Public Access: Ensure you don't accidentally make sensitive information public. Always double-check the contents of a bucket before altering access permissions at scale.

Use in Scripts: This method can be incorporated into larger automation scripts or deployment workflows, making it a valuable trick to have up your sleeve!

Conclusion:

Using the AWS CLI to mass-update object permissions in an S3 bucket is both efficient and powerful. Whether you're deploying a static website or just need to grant temporary access to a set of files, this method provides a reliable and scriptable approach. Always ensure to follow best security practices and keep an eye on your resources. Happy coding!