When old instances should be removed

The name of instances or clusters consists of part of the application (street or cms) and timestamp. By default, the timestamp is a current timestamp. After new instances are deployed, instances with an old timestamp are deleted.

After deleted old instances should be checked VPC network -> External IP addresses and deleted not used fixed IP addresses.

The "dev-ds" project is deployed automatically and timestamp added to Travis variable and doesn't change. If timestamp in Travis is changed, needs to delete the instance with an old timestamp.

The "prod-ds" consist of prod and pre-prod projects. Before deploy prod should be deleted pre-prod instances.
After deploying new instances to prod, should be switched prod URL to new instances in Cloudflare and pre-prod URL to previous instances. The previous instances don't delete for adding more stability and quickly switching to the previous version if it's needed.