GROK: help with pattern

[Guillermo_Valles_Cas (Guillermo)]

Hello!! I'm trying to get the pattern of a file in Logstash with GROK, but I do not know how to make it. The line I want to GROK is:

{"type":"log","@timestamp":"2021-05-19T08:45:42+02:00","tags":["info","plugins","actions","actions"],"pid":15909,"message":"Server log: [ALERT][testAlarm][nameClient][{\"condition0\":[\"30%\"]}][2021-05-19T06:45:40.085Z];"}

How it should be my filter part?

filter {
  grok {
    match => { "message" => "..." }
  }
}

[Badger]

Why not use a json filter instead of grok?

[Guillermo_Valles_Cas (Guillermo)]

That is a good point, thanks. Now my problem is more small than before because I just need to find a way to pull apart just this string:

Server log: [ALERT][testAlarm][nameClient][{\"condition0\":[\"30%\"]}][2021-05-19T06:45:40.085Z];

How I could get the pattern with GROK?

[Guillermo_Valles_Cas (Guillermo)]

I solve it without GROK:

filter{
	json {
		source => "message"
	}
	mutate {
		gsub => [
			"message", "{", "",
			"message", "}", "",
			"message", '"', ""
		]
	}
	dissect {
		mapping => {
			"message" => '%{e1} %{e2}: [%{e3}][%{e4}][%{e5}][%{e6}:[%{e7}]][%{e8}]'
		}
	}
}