Uly.me

cloud engineer

Leave a Comment

Failover Test

How to failover a website without actually doing a failover? It’s actually easier than you think. The key is to trick your computer that it’s pointing to a failover website. You can easily do this by editing your hosts file and adding a DNS entry. In both Linux and MacOS, you can edit the /etc/hosts file and add the failover site like the following below.

# /etc/hosts
# failover site
# xxx.xxx.xxx.xxx   yourdomain.com

xxx.xxx.xxx.xxx is the IP address of your failover site.
If you need to test the failover site, just uncomment the IP address.
Replace a comment if you’re done testing.

Leave a Comment

The Enigma Machine

It took about 2,000 Digital Ocean droplets, 13 minutes of compute time, and about $7 dollars worth of cloud resources, to break the Enigma code which were used by the Nazis in World War 2. The code was written in Python and ran as minions. The minions did the 99% of the grunt work. The droplets ran 41 million password combinations per second. What took years for Allied forces to break the code can now be decoded in just 13 minutes. Read the article.

Leave a Comment

Restrict Bucket To Users

How to restrict a S3 bucket to certain group of users. Edit the bucket policy and add the following.

{
    "Version": "2012-10-17",
    "Id": "bucketPolicy",
    "Statement": [
        {
            "Effect": "Deny",
            "NotPrincipal": {
                "AWS": "arn:aws:iam::xxxxxxxxxx:user/username",
                "AWS": "arn:aws:iam::xxxxxxxxxx:root",
            },
            "Action": "s3:*",
            "Resource": [
                "arn:aws:s3:::bucketname",
                "arn:aws:s3:::bucketname/*"
            ]
        }
    ]
}

Replace xxxxxxxxxx with your AWS account number.
Replace bucketname with your S3 bucket.
Replace username with your IAM user.
Root is your AWS root account.
Accounts must be valid.

Cloud

Linux

Subscribe