Merge pull request #94 from jbbarth/feature-add-nagios_nsca-output

Added nagios_nsca output (see ticket LOGSTASH-354)

lib/logstash/outputs/nagios_nsca.rb

@@ -0,0 +1,100 @@
+require "logstash/outputs/base"
+require "logstash/namespace"
+
+# The nagios_nsca output is used for sending passive check results to Nagios
+# through the NSCA protocol.
+#
+# This is useful if your Nagios server is not the same as the source host from
+# where you want to send logs or alerts. If you only have one server, this
+# output is probably overkill # for you, take a look at the 'nagios' output
+# instead.
+#
+# Here is a sample config using the nagios_nsca output:
+#     output {
+#       nagios_nsca {
+#         # specify the hostname or ip of your nagios server
+#         host => "nagios.example.com"
+#
+#         # specify the port to connect to
+#         port => 5667
+#       }
+#     }
+
+class LogStash::Outputs::NagiosNsca < LogStash::Outputs::Base
+
+  config_name "nagios_nsca"
+  plugin_status "experimental"
+
+  # The nagios host or IP to send logs to. It should have a NSCA daemon running.
+  config :host, :validate => :string, :default => "localhost"
+
+  # The port where the NSCA daemon on the nagios host listens.
+  config :port, :validate => :number, :default => 5667
+
+  # The path to the 'send_nsca' binary on the local host.
+  config :send_nsca_bin, :validate => :string, :default => "/usr/sbin/send_nsca"
+
+  # The path to the send_nsca config file on the local host.
+  # Leave blank if you don't want to provide a config file.
+  config :send_nsca_config, :validate => :string
+
+  # The nagios 'host' you want to submit a passive check result to. This
+  # parameter accepts interpolation, e.g. you can use @source_host or other
+  # logstash internal variables.
+  config :nagios_host, :validate => :string, :default => "%{@source_host}"
+
+  # The nagios 'service' you want to submit a passive check result to. This
+  # parameter accepts interpolation, e.g. you can use @source_host or other
+  # logstash internal variables.
+  config :nagios_service, :validate => :string, :default => "LOGSTASH"
+
+  public
+  def register
+    #nothing for now
+  end
+
+  public
+  def receive(event)
+    # catch logstash shutdown
+    if event == LogStash::SHUTDOWN
+      finished
+      return
+    end
+
+    # skip if 'send_nsca' binary doesn't exist
+    if !File.exists?(@send_nsca_bin)
+      @logger.warn("Skipping nagios_nsca output; send_nsca_bin file is missing",
+                   "send_nsca_bin" => @send_nsca_bin, "missed_event" => event)
+      return
+    end
+
+    # interpolate params
+    nagios_host = event.sprintf(@nagios_host)
+    nagios_service = event.sprintf(@nagios_service)
+
+    # escape basic things in the log message
+    # TODO: find a way to escape the message correctly
+    msg = event.to_s
+    msg.gsub!("\n", "<br/>")
+    msg.gsub!("'", "&#146;")
+
+    # build the command
+    # syntax: echo '<server>!<nagios_service>!<status>!<text>'  | \
+    #           /usr/sbin/send_nsca -H <nagios_host> -d '!' -c <nsca_config>"
+    # TODO: make nagios status configurable ; defaults to 1 = 'WARNING' for now.
+    cmd = %(echo '#{nagios_host}~#{nagios_service}~1~#{msg}' |)
+    cmd << %( #{@send_nsca_bin} -H #{@host} -p #{@port} -d '~')
+    cmd << %( -c #{@send_nsca_config}) if @send_nsca_config
+    cmd << %( 2>/dev/null >/dev/null)
+    @logger.debug("Running send_nsca command", "nagios_nsca_command" => cmd)
+
+    begin
+      system cmd
+    rescue => e
+      @logger.warn("Skipping nagios_nsca output; error calling send_nsca",
+                   "error" => $!, "nagios_nsca_command" => cmd,
+                   "missed_event" => event)
+      @logger.debug("Backtrace", e.backtrace)
+    end
+  end # def receive
+end # class LogStash::Outputs::NagiosNsca