Add regex pattern to match the query output

Author: jindraj

CHANGELOG.md

@@ -4,6 +4,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 This CHANGELOG follows the format listed [here](https://github.com/sensu-plugins/community/blob/master/HOW_WE_CHANGELOG.md).
 
 ## [Unreleased]
+### Added
+- `check-postgres-query.rb`: Add `-r`, `--regex-pattern` to match query result against (@jindraj)
+
 ### Changes
 - Updated development dependency to bundler ~> 2.1
 - Updated development dependency to rake ~> 13.0 

bin/check-postgres-query.rb

@@ -75,6 +75,11 @@ class CheckPostgresQuery < Sensu::Plugin::Check::CLI
          long: '--query QUERY',
          required: true
 
+  option :regex_pattern,
+         description: 'Regex pattern to match on query results and alert on if it does not match',
+         short: '-r REGEX',
+         long: '--regex-pattern REGEX'
+
   option :check_tuples,
          description: 'Check against the number of tuples (rows) returned by the query',
          short: '-t',
@@ -127,6 +132,8 @@ def run
       critical "Results: #{res.values}"
     elsif config[:warning] && calc.evaluate(config[:warning], value: value)
       warning "Results: #{res.values}"
+    elsif config[:regex_pattern] && (res.getvalue(0, 0) !~ /#{config[:regex_pattern]}/)
+      critical "Query result #{res.getvalue(0, 0)} doesn't match configured regex #{config[:regex_pattern]}"
     else
       ok 'Query OK'
     end