Logstash regex option for match settings!

Elastic Stack Logstash
1

In my settings, JSON is an input data. I tried to use log timestamp as index @timestamp value. Its working for normal json too.

But regex not working for nested json timestamp field match.

Here is my config.

	date {
			match => ["[a-zA-Z0-9][timestamp]", "YYYY-MM-dd HH:mm:ss"]
			target => "@timestamp"
                    }

Log file example:
{"SRV1": {"timestamp": "2016-09-09 00:30:40", "cpu": 90, "mem": 45, "disk_free": 50}}
{"SRV2": {"timestamp": "2016-09-09 00:30:40", "cpu": 80, "mem": 43, "disk_free": 64}}

Fyi,
This below configuration is working , but I have a 200 servers and its not possible to put 200 entries in the configuration. So I prefer to use regex on match settings.

	date {
			match => ["[SRV1][timestamp]", "YYYY-MM-dd HH:mm:ss"]
			target => "@timestamp"
                    }
	date {
			match => ["[SRV2][timestamp]", "YYYY-MM-dd HH:mm:ss"]
			target => "@timestamp"
                    }
2

This kind of regular expression matching isn't supported. I suggest you use a ruby filter to normalize each event by moving the server subfields (timestamp, cpu, mem, ...) into the top level of the event, or just rename the server name field to something consistent.