RUBY-2091 Provide stack trace for ismaster failures in monitor (#1647)

* RUBY-2091 Provide stack trace for ismaster failures in monitor

* Look for required text in warnings rather than mandating complete equality

Co-authored-by: Oleg Pudeyev <p@users.noreply.github.com>

Author: p-mongo

lib/mongo/server/connection.rb

@@ -322,7 +322,7 @@ def handshake!(socket)
               raise exc
             end
           rescue => e
-            log_warn("Failed to handshake with #{address}: #{e.class}: #{e}")
+            log_warn("Failed to handshake with #{address}: #{e.class}: #{e}:\n#{e.backtrace[0..5].join("\n")}")
             raise
           end
         end
@@ -379,7 +379,7 @@ def authenticate!(pending_connection)
             begin
               Auth.get(user).login(pending_connection)
             rescue => e
-              log_warn("Failed to handshake with #{address}: #{e.class}: #{e}")
+              log_warn("Failed to handshake with #{address}: #{e.class}: #{e}:\n#{e.backtrace[0..5].join("\n")}")
               raise
             end
           end

lib/mongo/server/monitor.rb

@@ -204,7 +204,7 @@ def ismaster
             connection.ismaster
           end
           if exc
-            log_debug("Error running ismaster on #{server.address}: #{exc.class}: #{exc.message}")
+            log_debug("Error running ismaster on #{server.address}: #{exc.class}: #{exc}:\n#{exc.backtrace[0..5].join("\n")}")
             if monitoring.monitoring?
               monitoring.failed(
                 Monitoring::SERVER_HEARTBEAT,

lib/mongo/server/monitor/connection.rb

@@ -232,7 +232,7 @@ def handshake!(socket)
             log_warn("Asked to handshake with #{address} but there was no app metadata provided")
           end
         rescue => e
-          log_warn("Failed to handshake with #{address}: #{e.class}: #{e}")
+          log_warn("Failed to handshake with #{address}: #{e.class}: #{e}:\n#{e.backtrace[0..5].join("\n")}")
           raise
         end
 

spec/mongo/server/connection_spec.rb

@@ -137,12 +137,13 @@ class ConnectionSpecTestException < Exception; end
 
         it 'logs a warning' do
           messages = []
-          # Straightforward expectations are not working here for some reason
           expect(Mongo::Logger.logger).to receive(:warn) do |msg|
             messages << msg
           end
+
           expect(error).not_to be nil
-          expect(messages).to include(expected_message)
+
+          messages.any? { |msg| msg.include?(expected_message) }.should be true
         end
 
       end

spec/mongo/server/monitor/connection_spec.rb

@@ -189,10 +189,17 @@
 
       it 'logs a warning' do
         expect_any_instance_of(Mongo::Socket).to receive(:write).and_raise(Mongo::Error::SocketError, 'test error')
-        expect(Mongo::Logger.logger).to receive(:warn).with(expected_message).and_call_original
+
+        messages = []
+        expect(Mongo::Logger.logger).to receive(:warn) do |msg|
+          messages << msg
+        end
+
         expect do
           monitor.connection.connect!
         end.to raise_error(Mongo::Error::SocketError, 'test error')
+
+        messages.any? { |msg| msg.include?(expected_message) }.should be true
       end
     end
   end