Updated the file to be compatible with 6.0.0

lib/logstash/outputs/tcp.rb

@@ -51,8 +51,6 @@ class LogStash::Outputs::Tcp < LogStash::Outputs::Base
   # SSL key passphrase
   config :ssl_key_passphrase, :validate => :password, :default => nil
 
-  config :message_format, :validate => :string, :obsolete => "This setting is obsolete. The event will be formatted according to the codec used"
-
   class Client
     public
     def initialize(socket, logger)
@@ -85,8 +83,12 @@ def setup_ssl
     require "openssl"
 
     @ssl_context = OpenSSL::SSL::SSLContext.new
-    @ssl_context.cert = OpenSSL::X509::Certificate.new(File.read(@ssl_cert))
-    @ssl_context.key = OpenSSL::PKey::RSA.new(File.read(@ssl_key),@ssl_key_passphrase)
+    if @ssl_cert
+      @ssl_context.cert = OpenSSL::X509::Certificate.new(File.read(@ssl_cert))
+      if @ssl_key
+        @ssl_context.key = OpenSSL::PKey::RSA.new(File.read(@ssl_key),@ssl_key_passphrase)
+      end
+    end
     if @ssl_verify
       @cert_store = OpenSSL::X509::Store.new
       # Load the system default certificate path to the store
@@ -150,8 +152,8 @@ def register
         begin
           client_socket = connect unless client_socket
           r,w,e = IO.select([client_socket], [client_socket], [client_socket], nil)
-          loop do
-            break if !r.any?
+          # Read everything first
+          while r.any? do
             # don't expect any reads, but a readable socket might
             # mean the remote end closed, so read it and throw it away.
             # we'll get an EOFError if it happens.
@@ -162,7 +164,7 @@ def register
           # Now send the payload
           client_socket.syswrite(payload) if w.any?
         rescue => e
-          @logger.warn("tcp output exception", :host => @host, :port => @port,
+          @logger.warn("tcp output exception, will retry", :host => @host, :port => @port,
                        :exception => e, :backtrace => e.backtrace)
           client_socket.close rescue nil
           client_socket = nil
@@ -204,4 +206,4 @@ def server?
   def receive(event)
     @codec.encode(event)
   end # def receive
-end # class LogStash::Outputs::Tcp
+end # class LogStash::Outputs::Tcp