This assumes you have already configured the aws command line tool. If not, check out my article on Getting Started with the AWS CLI.

An S3 Bucket is similar to an NFS share in that it is a mountable storage volume.

The aws s3api list-buckets command can be used to list your S3 buckets.

~]$ aws s3api list-buckets
{
    "Buckets": [
        {
            "Name": "my-bucket-abcdefg",
            "CreationDate": "2023-06-02T02:22:19+00:00"
        }
    ],
    "Owner": {
        "DisplayName": "john.doe",
        "ID": "ab0e0a411234d5103a77c82240d5abcdc41ff11cc325c65b5c777a5123443743"
    }
}

The aws s3api get-public-access-block​ command can be used to determine if the S3 Bucket has a public access block. In this example, the S3 Bucket Public Access Blocks are false, meaning Public Access is allowed.

does have a public access block which means that public access to the S3 Bucket is disabled.

~]$ aws s3api get-public-access-block --bucket my-bucket-abcdefg
{
    "PublicAccessBlockConfiguration": {
        "BlockPublicAcls": false,
        "IgnorePublicAcls": false,
        "BlockPublicPolicy": false,
        "RestrictPublicBuckets": false
    }
}

The aws s3api put-public-access-block command can be used to add public access block to the S3 Bucket.

aws s3api put-public-access-block \
--bucket my-bucket-abcdefg \
--public-access-block-configuration "BlockPublicAcls=true,IgnorePublicAcls=true,BlockPublicPolicy=true,RestrictPublicBuckets=true"

And then you can confirm that the Public Access Blocks are set to true.

~]$ aws s3api get-public-access-block --bucket my-bucket-abcdefg
{
    "PublicAccessBlockConfiguration": {
        "BlockPublicAcls": true,
        "IgnorePublicAcls": true,
        "BlockPublicPolicy": true,
        "RestrictPublicBuckets": true
    }
}