Changing the IP Address for a Host Name Entry in Route53

The failover can be execute by changing the IP address for a given host name. This means a A record has to be introducted or modified.

This can be done through a CLI command. The information required is:

• Route53 hosted zone id: for example HOSTED-ZONE-ID
• name of entry: for example myservice
• IP address for entry: for example 10.79.252.13 
• domain name: for example myvpc.mycompany.com
• Time to life (TTL): for example 10s 

Prework

Find your hosted zone through using the AWS console or the AWS CLI command:

aws route53 list-hosted-zones

Create a file like change-resource-record-sets.json:

{
    "Comment": "Update record to reflect new IP address for a system ",
    "Changes": [
        {
            "Action": "UPSERT",
            "ResourceRecordSet": {
                "Name": "myservice.myvpc.mycompany.com",
                "Type": "A",
                "TTL": 10,
                "ResourceRecords": [
                    {
                        "Value": "10.79.252.13"
                    }
                ]
            }
        }
    ]
}

Replace the string myservice.myvpc.mycompany.com with the host name and the domain which matches your requirements.

Replace 10.79.252.13 with the IP address where your service is being provided.

Changing the A record in Route53

Use the following AWS CLI command to implement the change:

aws route53 change-resource-record-sets --hosted-zone-id HOSTED-ZONE-ID --change-batch file:///mypath/change-resource-record-sets.json

Replace HOSTED-ZONE-ID with the identifier for your hosted zone. Pick the correct path to your json configuration file.

This command can be used to create an A record initially. It will work as well if the record already exists. It will then update the IP address and the TTL value.

The command will return a transaction Id which should be caught...

Checking Progess of the Update

The Route53 update takes as while (~20s). The successfull completion of the transaction can be checked with the following command:

aws route53 get-change --id <value>

The result will provide a status field which is PENDING or INSYNC.