call connection check after connect

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 7.0.1
+  - Invoke post_connection_check on connect [#61](https://github.com/logstash-plugins/logstash-output-tcp/pull/61)
+
 ## 7.0.0
   - SSL settings that were marked deprecated in version `6.2.0` are now marked obsolete, and will prevent the plugin from starting.
   [#58](https://github.com/logstash-plugins/logstash-output-tcp/pull/58)

lib/logstash/outputs/tcp.rb

@@ -264,7 +264,7 @@ def run_as_client
     client_socket = nil
     @codec.on_event do |event, payload|
       begin
-        client_socket = connect unless client_socket
+        client_socket = retryable_connect unless client_socket
         while payload && payload.bytesize > 0
           begin
             written_bytes_size = client_socket.write_nonblock(payload)
@@ -316,32 +316,34 @@ def log_error(msg, e, backtrace: @logger.info?, **details)
     @logger.error(msg, details)
   end
 
-  private
-
   def connect
-    begin
-      client_socket = TCPSocket.new(@host, @port)
-      if @ssl_enabled
-        client_socket = OpenSSL::SSL::SSLSocket.new(client_socket, @ssl_context)
-        begin
-          client_socket.connect
-        rescue OpenSSL::SSL::SSLError => ssle
-          log_error 'connect ssl failure:', ssle, backtrace: false
-          # NOTE(mrichar1): Hack to prevent hammering peer
-          sleep(5)
-          raise
-        end
+    client_socket = TCPSocket.new(@host, @port)
+    if @ssl_enabled
+      client_socket = OpenSSL::SSL::SSLSocket.new(client_socket, @ssl_context)
+      begin
+        client_socket.connect
+        client_socket.post_connection_check(@host) if @ssl_verification_mode == 'full'
+      rescue OpenSSL::SSL::SSLError => ssle
+        log_error 'connect ssl failure:', ssle, backtrace: false
+        client_socket.close rescue nil
+        raise
       end
-      client_socket.extend(::LogStash::Util::SocketPeer)
-      @logger.debug("opened connection", :client => client_socket.peer)
-      return client_socket
-    rescue => e
-      log_error 'failed to connect:', e
-      sleep @reconnect_interval
-      retry
     end
-  end # def connect
+    client_socket.extend(::LogStash::Util::SocketPeer)
+    @logger.debug("opened connection", :client => client_socket.peer)
+    client_socket
+  end
 
+  private
+  def retryable_connect
+    connect
+  rescue => e
+    log_error 'failed to connect:', e
+    sleep @reconnect_interval
+    retry
+  end
+
+  private
   def validate_ssl_config!
     unless @ssl_enabled
       ignored_ssl_settings = original_params.select { |k| k != 'ssl_enabled' && k != 'ssl_enable' && k.start_with?('ssl_') }

logstash-output-tcp.gemspec

@@ -1,7 +1,7 @@
 Gem::Specification.new do |s|
 
   s.name            = 'logstash-output-tcp'
-  s.version         = '7.0.0'
+  s.version         = '7.0.1'
   s.licenses        = ['Apache License (2.0)']
   s.summary         = "Writes events over a TCP socket"
   s.description     = "This gem is a Logstash plugin required to be installed on top of the Logstash core pipeline using $LS_HOME/bin/logstash-plugin install gemname. This gem is not a stand-alone program"

spec/outputs/tcp_spec.rb

@@ -144,7 +144,7 @@
   context "client mode" do
     before { subject.register }
 
-    let(:config) { super().merge 'mode' => 'client' }
+    let(:config) { super().merge('mode' => 'client', 'host' => 'localhost') }
 
     it 'writes payload data' do
       Thread.start { sleep 0.25; subject.receive event }
@@ -248,28 +248,65 @@
           expect( read ).to end_with 'foo bar'
         end
 
+        context 'with ssl_verification_mode => full' do
+          let(:config) do
+            {
+              "mode" => "client",
+              "host" => "localhost",
+              "port" => port,
+              "ssl_enabled" => true,
+              "ssl_certificate_authorities" => crt_file,
+              "ssl_verification_mode" => "full",
+              "codec" => "plain"
+            }
+          end
+
+          context "with right host name" do
+            let(:config) { super().merge("host" => "localhost") }
+            it 'reads plain data' do
+              thread = Thread.start { sleep 0.25; subject.receive event }
+              socket = secure_server.accept
+              read = socket.sysread(100)
+              expect( read.size ).to be > 0
+              expect( read ).to end_with 'foo bar'
+            end
+          end
+
+          context "with wrong host name" do
+            let(:config) { super().merge("host" => "127.0.0.1") }
+            it 'closes the connection' do
+              thread = Thread.start do
+                sleep 0.25
+                expect { subject.connect }.to raise_error(OpenSSL::SSL::SSLError, /hostname "127.0.0.1" does not match the server certificate/)
+              end
+              secure_server.accept rescue nil # the other side will close the connection potentially causing a "Socket closed" error
+              thread.join
+            end
+          end
+        end
+
       end
 
       context 'with unsupported protocol (on server)' do
 
-        let(:config) { super().merge("ssl_supported_protocols" => ['TLSv1.1']) }
+        let(:config) { super().merge("ssl_supported_protocols" => ['TLSv1.1'], "reconnect_interval" => 1) }
 
         let(:server_min_version) { 'TLS1_2' }
 
         before { subject.register }
         after { secure_server.close }
 
         it 'fails (and loops retrying)' do
-          expect(subject.logger).to receive(:error).with(/connect ssl failure/i, hash_including(message: /No appropriate protocol/i)).and_call_original
-          expect(subject.logger).to receive(:error).with(/failed to connect/i, hash_including(exception: OpenSSL::SSL::SSLError)).and_call_original
+          expect(subject.logger).to receive(:error).twice.with(/connect ssl failure/i, hash_including(message: /No appropriate protocol/i)).and_call_original
+          expect(subject.logger).to receive(:error).twice.with(/failed to connect/i, hash_including(exception: OpenSSL::SSL::SSLError)).and_call_original
           expect(subject).to receive(:sleep).once.and_call_original
           expect(subject).to receive(:sleep).once.and_throw :TEST_DONE # to be able to abort the retry loop
 
           Thread.start { secure_server.accept rescue nil }
-          expect { subject.receive event }.to throw_symbol(:TEST_DONE)
+          expect { sleep 0.25; subject.receive event }.to throw_symbol(:TEST_DONE)
         end
 
-      end if LOGSTASH_VERSION > '7.0'
+      end
 
     end