ShortenedThrowableConverter : How to exclude frames that contains $ (dollar sign)?

[hexwit]

Hi, I have a stack trace where correct (as per my opinion) exclude patterns does not work.

Patterns:

• io.proj..*$$FastClassBySpringCGLIB$$
• org.springframework.security.web.FilterChainProxy$VirtualFilterChain.*

Stack trace:

io.proj.exceptions.SecurityException: AUTHENTICATION_FAILED(email:[email protected])
	at io.proj.controllers.SessionController.create(SessionController.java:52)
	at io.proj.controllers.SessionController$$FastClassBySpringCGLIB$$894cc6e6.invoke(<generated>)
	... 21 frames excluded
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1070)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:665)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:750)
	at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:74)
	... 2 frames excluded
	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:115)
	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:81)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346)
	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:122)
	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:116)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346)
	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:126)
	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:81)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346)
	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:109)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346)
	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:149)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346)
	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346)
	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:103)
	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:89)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:346)
	at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:90)
	at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:75)

So logback keeps frames even provided patterns are matched in a regexp verification software. so I know there is a match.
Either this is an issue with $ sign processing, or I am missing something.

Please bring some light on this problem, if you could.
Thanks.

[brenuart]

Exclude patterns are REGEX expressions for which the dollar sign and the dot have special meanings (respectively end of line and any single character).
In your case you want to match the dollar and the dot literals so you need to ESCAPE them as follows:

<encoder class="net.logstash.logback.encoder.LogstashEncoder">
    <throwableConverter class="net.logstash.logback.stacktrace.ShortenedThrowableConverter">
        <exclude>^io\.proj\..*\$\$FastClassBySpringCGLIB\$\$.*</exclude>
        <exclude>^org\.springframework\.security\.web\.FilterChainProxy\$VirtualFilterChain.*</exclude>
    </throwableConverter>
</encoder>

That said, the converter effectively removes stack trace elements ONLY if at least TWO consecutive lines are excluded. This is so to avoid replacing the single element with "... 1 frames excluded" which doesn't shorten the stack trace at all...
Stated differently, although your patterns will match the lines you want to exclude, they won't be removed from the stack trace.

I know the documentation is not very clear about this behaviour. Sorry about that. We'll do our best to review it asap.

[hexwit]

My example was exactly with back slashes, but seems to be I had to mark patterns as code, so github do not change it, and unfortunately I missed that. Yes, I was aware about special meaning of specific regexp but I was not aware about amount of matches.
Thank you very much for the clarification!

[hexwit]

Please add statement about "ONLY if at least TWO consecutive lines are excluded." into documentation. I just checked and didn't find it.

[brenuart]

Yes, we will - I have created an issue to cover this part of the documentation (see #864)