Grok custom pattern problem (Can't start with a number) - Logstash 1.5

Hi,

it was previously OK with Logstash 1.4.2
it now BUG with Logstash 1.5

My pattern file contain a grok pattern with a name starting with a number

Step to reproduce :

1 - Add this pattern to grok patterns :
- 123_DATE %{YEAR:123_date}
- YEAR_DATE %{YEAR:year_date}

2 - Start Logstash with the following commands :
- ./logstash agent -e 'filter { grok { match => ["message","%{123_DATE:year}"] } }'
- ./logstash agent -e 'filter { grok { match => ["message","%{YEAR_DATE:year}"] } }'

3 - RESULTS
- Logstash 1.4.2

  [pi@mars logstash-1.4.2/bin]$ ./logstash agent -e 'filter { grok { match => ["message","%{123_DATE:year}"] } }'

  2015

  {

     "message" => "2015",

    "@version" => "1",

  "@timestamp" => "2015-06-01T08:50:55.018Z",

        "type" => "stdin",

        "host" => "mars",

        "year" => "2015",

    "123_date" => "2015"

  }

  Interrupt received. Shutting down the pipeline. {:level=>:warn}

  [pi@mars logstash-1.4.2/bin]$ ./logstash agent -e 'filter { grok { match => ["message","%{YEAR_DATE:year}"] } }'

  2015

  {

     "message" => "2015",

    "@version" => "1",

  "@timestamp" => "2015-06-01T08:51:13.516Z",

        "type" => "stdin",

        "host" => "mars",

        "year" => "2015",

   "year_date" => "2015"

  }

  

- Logstash 1.5

[pi@mars logstash-1.5.0/bin]$ ./logstash agent -e 'filter { grok { match => ["message","%{123_DATE:year}"] } }'

The error reported is:

  invalid group name <123_DATE:year>: /(?<123_DATE:year>(?(?>\d\d){1,2}))/m

[pi@mars logstash-1.5.0/bin]$ ./logstash agent -e 'filter { grok { match => ["message","%{YEAR_DATE:year}"] } }'

Logstash startup completed

2015

{

       "message" => "2015",

      "@version" => "1",

    "@timestamp" => "2015-06-01T08:42:46.059Z",

          "type" => "stdin",

          "host" => "mars",

          "year" => "2015",

     "year_date" => "2015"

}

Please correct this or just write it somewhere in red inside the documentation.

EDIT : Please note that a name like this : DATE_123_CUSTOM is ok because the name is not starting with a number. (I've just made the test)

M0dM