Logstash configure for parse json from text file

Logstash configure for parse json from text file

filter {
    grok {
      match => { "message" => "^\[%{TIMESTAMP_ISO8601:datetime}\]\s+%{DATA:env}\s+%{LOGLEVEL:loglevel}+\:%{GREEDYDATA:log_msg}" }

      add_field => {
                     "received_at" =>"%{datetime}"
                     "enviroment" => "%{env}"
                     "log_level" => "%{loglevel}"
                  }
       }
     json{
                "source" => "log_msg"
                "target" => "parsedMsg"
                "remove_field" => ["log_msg"]
        }
       mutate {
           "add_field" => {
               'file' => "%{[parsedMsg][message][debug_backtrace][file]}"
               'function' => "%{[parsedMsg][message][debug_backtrace][function]}"
               'args' => "%{[parsedMsg][message][debug_backtrace][args]}"
                'line' => "%{[parsedMsg][message][debug_backtrace][line]}"
           }
       }
}