rsyslog %syslogseverity-text% crit => critical

[oshamin]

I discovered issue with rsyslog default name for critical severity.
Rsyslog use "crit" (%syslogseverity-text%) priority name for critical events.

But fluent-plugin-google-cloud can not recognize this.

` # Values permitted by the API for 'severity' (which is an enum).
VALID_SEVERITIES = Set.new(
%w(DEFAULT DEBUG INFO NOTICE WARNING ERROR CRITICAL ALERT EMERGENCY))

# Translates other severity strings to one of the valid values above.
SEVERITY_TRANSLATIONS = {
  # log4j levels (both current and obsolete).
  'WARN' => 'WARNING',
  'FATAL' => 'CRITICAL',
  'TRACE' => 'DEBUG',
  'TRACE_INT' => 'DEBUG',
  'FINE' => 'DEBUG',
  'FINER' => 'DEBUG',
  'FINEST' => 'DEBUG',
  # single-letter levels.  Note E->ERROR and D->DEBUG.
  'D' => 'DEBUG',
  'I' => 'INFO',
  'N' => 'NOTICE',
  'W' => 'WARNING',
  'E' => 'ERROR',
  'C' => 'CRITICAL',
  'A' => 'ALERT',
  # other misc. translations.
  'ERR' => 'ERROR',
  'F' => 'CRITICAL'
}

`

Here is my syslogd template:
$template format_local, "%timegenerated:::date-rfc3339% %syslogseverity-text% %msg%\n"

here is cut from log file
2016-10-27T16:36:05.175063+00:00 crit MESSSAGE

As a result, google logs viewer does not mark "crit" events as critical.

[jkohen]

@igorpeshansky can you triage? On the surface it seems related to #51