Regex Tester & Validator

Matches an ETCD_INITIAL_CLUSTER configuration line, capturing up to two cluster member entries (name=https://IP:2380) before and after a specific target host, 'app-failedhost-eeeeeeeeee.node.consul'. The three capture groups isolate the failing node's entry so it can be stripped out via re.sub while preserving surrounding entries. Useful for programmatically removing a dead node from etcd cluster configuration files.