This utility is designed to check the validity of certificates. It will check:

• expiration dates (both expired and not yet valid, also for CA)
• certificate and key are matching
• CA is matching

if any error it will exit 1.

Background: Managing certifcates is painful and when dealing with semi automtic process it can lead to human errors. This tool can be added to your automation software as a pre check before changing certificates. For example I am using Puppet and this allows me the use the validate_cmd

file { '/etc/ssl/example.pem':
  content      => 'insert cert here',
  validate_cmd => '/usr/local/sbin/go-ssl --cert %',
}

While I am not not familiar with Ansible you should be able to use the validate function