Logstash filter for squid log

squid.conf

# Content of the file /etc/logstash/conf.d/squid.conf
# Squid logs MAC address of the source host
# Logs are sending by syslog-ng raw without standard log headers

input {
  tcp {
        host => "xxx.xxx.xxx.xxx"
        port => xxxx
        type => SQUID
        tags => [SQUID]
        }

}

filter {
if [type] == "SQUID" {
        grok {
                match => [ "message", "%{NUMBER:timestamp}\s+%{NUMBER:request_msec:float} %{IPORHOST:src_ip} %{COMMONMAC:src_mac} %{WORD}/%{NUMBER:response_status:int} %{NUMBER:response_size:int} %{WORD:http_method} (%{URIPROTO:http_proto}://)?%{IPORHOST2:dst_host}(?::%{POSINT:port})?(?:%{NOTSPACE:uri_param})? %{USERNAME:user} %{WORD}/(%{IPORHOST:dst_ip}|-) %{GREEDYDATA:content_type}" ]

        }
        date {
                match => [ "timestamp", "UNIX" ]
                remove_field => [ "timestamp" ]
        }
  if [dst_ip] {
    geoip {
      source => "dst_ip"
      target => "dst_geoip"
      database => "/opt/logstash/vendor/geoip/GeoLiteCity.dat"
      fields => [ "country_code2", "country_name" ]
    }
  }
}
}

output {
        if [type] == "SQUID" {
                elasticsearch {
                        flush_size => 1000
                        protocol => "transport"
                        host => "xxx.xxx.xxx.xxx"
                        cluster => "xxxxx"
                        index => "logstash-squid-%{+YYYY.MM.dd}"
                }
        }
}

I'm trying to use your filter but I get the following error:
pattern %{IPORHOST2:dst_host} not defined"}

It could be related with the version of logstash-patterns-core?

Should be %{IPORHOST}

Try this instead:

%{NUMBER:timestamp}%{SPACE}%{NUMBER:request_msec:float} %{IPORHOST:src_ip} %{WORD}/%{NUMBER:response_status:int} %{NUMBER:response_size} %{WORD:http_method} (%{URIPROTO:http_proto}://)?%{IPORHOST:dst_host}(?::%{POSINT:port})?(?:%{NOTSPACE:uri_param})? %{USERNAME:user} %{WORD}/(%{IPORHOST:dst_ip}|-)%{GREEDYDATA:content_type}

@r57shell - thanks; the original squid grok pattern wasn't working for me either but yours does!