Added TCP port checker

lib/watchmonkey_cli.rb

@@ -35,11 +35,12 @@
 require "watchmonkey_cli/checkers/ftp_availability"
 require "watchmonkey_cli/checkers/mysql_replication"
 require "watchmonkey_cli/checkers/ssl_expiration"
+require "watchmonkey_cli/checkers/tcp_port"
+require "watchmonkey_cli/checkers/ts3_license"
 require "watchmonkey_cli/checkers/unix_defaults"
 require "watchmonkey_cli/checkers/unix_df"
 require "watchmonkey_cli/checkers/unix_file_exists"
 require "watchmonkey_cli/checkers/unix_load"
 require "watchmonkey_cli/checkers/unix_mdadm"
 require "watchmonkey_cli/checkers/unix_memory"
-require "watchmonkey_cli/checkers/ts3_license"
 require "watchmonkey_cli/checkers/www_availability"

lib/watchmonkey_cli/application/configuration.tpl

@@ -59,6 +59,20 @@ www_availability "https://example.com", ssl_expiration: false
 www_availability "https://example.com", ssl_expiration: { threshold: 4.weeks }
 
 
+# -----
+# TCP port
+# -----
+# Attempts to establish a TCP connection to a given port.
+# Host might be :local/SSH connection/String(IP/DNS)
+# Available options:
+#
+#   message    Error message when connection cannot be established
+#   timeout    Timeout in seconds to wait for a connection (default = 2 seconds - false/nil = 1 hour)
+#
+tcp_port "ftp.example.com", 21, message: "FTP offline"
+tcp_port :my_server, 21, message: "FTP offline"
+
+
 # -----
 # FTP availability
 # -----

lib/watchmonkey_cli/checkers/tcp_port.rb

@@ -0,0 +1,29 @@
+module WatchmonkeyCli
+  module Checkers
+    class TcpPort < Checker
+      self.checker_name = "tcp_port"
+
+      def enqueue host, port, opts = {}
+        opts = { message: "Port #{port} (TCP) is not reachable!", timeout: 2 }.merge(opts)
+        host = app.fetch_connection(:loopback, :local) if !host || host == :local
+        host = app.fetch_connection(:ssh, host) if host.is_a?(Symbol)
+        app.enqueue(self, host, port, opts)
+      end
+
+      def check! result, host, port, opts = {}
+        result.result = port_open?(host.is_a?(String) ? host : host.is_a?(WatchmonkeyCli::LoopbackConnection) ? "127.0.0.1" : host.opts[:host_name] || host.opts[:host] || host.opts[:ip], port, opts)
+        result.error! "#{opts[:message]}" unless result.result
+      end
+
+      def port_open?(ip, port, opts = {})
+        Timeout::timeout(opts[:timeout] ? opts[:timeout] : 3600) do
+          s = TCPSocket.new(ip, port)
+          s.close
+        end
+        true
+      rescue Errno::ECONNREFUSED, Errno::EHOSTUNREACH, Timeout::Error
+        return false
+      end
+    end
+  end
+end

lib/watchmonkey_cli/ssh_connection.rb

@@ -1,5 +1,7 @@
 module WatchmonkeyCli
   class SshConnection
+    attr_reader :opts
+
     def initialize(id, opts = {}, &initializer)
       @id = id