Spring-cloud-netflix: Ribbon error (e.g. downstream 404 or timeout) in Zuul proxy bypasses normal Spring Boot error handling

[dsyer]

The response is probably being manipulated directly somewhere, so the tomcat error page shows up (HTML) instead of the normal Spring Boot one (JSON).

[dsyer]

I can't reproduce this now. Leaving it open in case it pops back again.

[leofromgroza]

I've reproduced bug using Spring Cloud Brixton.RC1 + Spring Boot 1.3.3.RELEASE + Spring Security. Here is an example:
STR:

• Just clone project https://github.com/leofromgroza/zuul-server
• Start Spring Boot Application.
• Open URL http://localhost:8765/dummy/ (credentials -> user:password) and you will see standard Tomcat error page.

Turn Spring Security off:

• Comment Spring Security dependency in pom.xml file
• Comment security configuration in application.yml.

Restart app and open URL http://localhost:8765/dummy/ - you will see custom error page.

I debugged program and found that if Spring Security is turned on - app wraps javax.servlet.AsyncContext into org.springframework.security.web.servletapi.HttpServlet3RequestFactory$SecurityContextAsyncContext and Tomcat does not commit Response in method org.apache.catalina.core.ApplicationDispatcher#doForward because of check in line 394.

Also I found that if error happened and response is not committed Tomcat default behavior is to create his own error page: org.apache.catalina.valves.ErrorReportValve#invoke

[dsyer]

Thanks for the sample app. I raised a ticket in Spring Security for that specific problem (which only seems to show up when you have a custom error handler as you do): https://github.com/spring-projects/spring-security/issues/3780.

I also noticed while investigating this that if there is an error rendering the custom error page you get the same effect.

[rwinch]

@leofromgroza Thanks for the detailed walk through! This appears to be a bug in Tomcat. However, the workaround was simple so I pushed a fix to master. Please see https://github.com/spring-projects/spring-security/issues/3780#issuecomment-204427591 for additional details (including a link to the bug report I filed with Tomcat).

[leofromgroza]

@dsyer @rwinch Thank you guys for so fast reaction. You are really cool! I felt the real power of open source;) Thank you!

[spencergibb]

@dsyer are we still tracking this here or can we close it?