Merge pull request #514 from dpeters/check-netstat

Add check-netstat-tcp.rb, heavily based on metrics-netstat-tcp.rb

plugins/network/check-netstat-tcp.rb

@@ -0,0 +1,125 @@
+#!/usr/bin/env ruby
+#
+# Check thresholds for TCP socket state metrics
+# ===
+#
+# Alert based on thresholds of discrete TCP socket states reported by netstat
+#
+# Example
+# -------
+#
+# $ ./check-netstat-tcp.rb --states ESTABLISHED,CLOSE_WAIT --warning 10,3 --critical 100,30
+# CheckNetstatTCP: Warn:ESTABLISHED=18 OK:CLOSE_WAIT=0
+# $ echo $?
+# 1
+# $
+#
+# Acknowledgements
+# ----------------
+# - Thanks to metric-netstat-tcp.rb!
+#   https://github.com/sensu/sensu-community-plugins
+#   - Code for parsing Linux /proc/net/tcp from Anthony Goddard's ruby-netstat:
+#     https://github.com/agoddard/ruby-netstat
+#
+# Released under the same terms as Sensu (the MIT license); see LICENSE
+# for details.
+#
+# rubocop:disable FavorUnlessOverNegatedIf
+
+require 'rubygems' if RUBY_VERSION < '1.9.0'
+require 'sensu-plugin/check/cli'
+require 'socket'
+
+TCP_STATES = {
+  '00' => 'UNKNOWN',  # Bad state ... Impossible to achieve ...
+  'FF' => 'UNKNOWN',  # Bad state ... Impossible to achieve ...
+  '01' => 'ESTABLISHED',
+  '02' => 'SYN_SENT',
+  '03' => 'SYN_RECV',
+  '04' => 'FIN_WAIT1',
+  '05' => 'FIN_WAIT2',
+  '06' => 'TIME_WAIT',
+  '07' => 'CLOSE',
+  '08' => 'CLOSE_WAIT',
+  '09' => 'LAST_ACK',
+  '0A' => 'LISTEN',
+  '0B' => 'CLOSING'
+}
+
+class CheckNetstatTCP < Sensu::Plugin::Check::CLI
+
+  option :states,
+    :description => "Comma delimited list of states to check",
+    :short => "-s STATES",
+    :long => "--states STATES",
+    :default => "ESTABLISHED",
+    :proc => proc {|a| a.split(',') }
+
+  option :critical,
+    :description => "Comma delimited list of state values to set critical at (order follows 'states')",
+    :short => "-c CRITICAL",
+    :long => "--critical CRITICAL",
+    :default => [1000],
+    :proc => proc {|a| a.split(',').map(&:to_i) }
+
+  option :warning,
+    :description => "Comma delimited list of state values to set warning at (order follows 'states')",
+    :short => "-w WARNING",
+    :long => "--warning WARNING",
+    :default => [500],
+    :proc => proc {|a| a.split(',').map(&:to_i) }
+
+  option :port,
+    :description => "Port you wish to check values on (default: all)",
+    :short => "-p PORT",
+    :long => "--port PORT",
+    :proc => proc {|a| a.to_i }
+
+  def netstat(protocols = ['tcp'])
+    state_counts = Hash.new(0)
+    TCP_STATES.each_pair { |hex, name| state_counts[name] = 0 }
+
+    protocols.each do |protocol|
+      File.open('/proc/net/' + protocol).each do |line|
+        line.strip!
+        if m = line.match(/^\s*\d+:\s+(.{8}|.{32}):(.{4})\s+(.{8}|.{32}):(.{4})\s+(.{2})/) # rubocop:disable AssignmentInCondition
+          connection_state = m[5]
+          connection_port = m[2].to_i(16)
+          connection_state = TCP_STATES[connection_state]
+          next unless config[:states].include?(connection_state)
+          if config[:port] && config[:port] == connection_port
+            state_counts[connection_state] += 1
+          elsif !config[:port]
+            state_counts[connection_state] += 1
+          end
+        end
+      end
+    end
+    state_counts
+  end
+
+  def run
+    state_counts = netstat(['tcp', 'tcp6'])
+    is_critical = false
+    is_warning = false
+    message = ""
+
+    config[:states].each_index do |i|
+      if state_counts[config[:states][i]] >= config[:critical][i]
+        is_critical = true
+        message += " CRITICAL:#{config[:states][i]}=#{state_counts[config[:states][i]]}"
+      elsif state_counts[config[:states][i]] >= config[:warning][i]
+        is_warning = true
+        message += " WARNING:#{config[:states][i]}=#{state_counts[config[:states][i]]}"
+      else
+        message += " OK:#{config[:states][i]}=#{state_counts[config[:states][i]]}"
+      end
+    end
+
+    critical message if is_critical
+    warning message if is_warning
+    ok message
+
+  end
+
+end