Camunda Cockpit and rest engine on tomee

[kanschik...@googlemail.com]

Hi all,

We try to use camunda cockpit and rest engine on tomee and can't get it up and running.

Versions:
tomee-jaxrs: 1.6.0
camunda: 7.0.0

When I call the rest engine first, it works, but a subsequent call of the camunda webapp fails with:
Jan 10, 2014 5:11:20 PM org.camunda.bpm.engine.rest.exception.ExceptionHandler toResponse
Warnung: javax.ws.rs.WebApplicationException
at org.apache.cxf.jaxrs.interceptor.JAXRSInInterceptor.processRequest(JAXRSInInterceptor.java:162)
at org.apache.cxf.jaxrs.interceptor.JAXRSInInterceptor.handleMessage(JAXRSInInterceptor.java:91)
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:262)
at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:237)
at org.apache.openejb.server.cxf.rs.CxfRsHttpListener.onMessage(CxfRsHttpListener.java:170)
at org.apache.openejb.server.rest.RsServlet.service(RsServlet.java:53)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
...

If I call the cockpit first, it works (including the embedded est engine on path /camunda/api/engine), but a subsequent call of the rest api causes an exception:
java.lang.ClassCastException: org.jboss.resteasy.core.ThreadLocalResteasyProviderFactory cannot be cast to org.jboss.resteasy.spi.ResteasyProviderFactory
org.jboss.resteasy.spi.ResteasyProviderFactory.getInstance(ResteasyProviderFactory.java:353)
org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:222)
org.jboss.resteasy.plugins.server.servlet.FilterDispatcher.doFilter(FilterDispatcher.java:59)
org.camunda.bpm.engine.rest.filter.CacheControlFilter.doFilter(CacheControlFilter.java:47)

Does anybody have experience with tomee and camunda?

Any ideas how this could be resolved?

Many thanks and regards,

Jens.

[Christian Lipphardt]

Hi Jens,

how do you setup camunda bpm on TomEE?

I followed the vanilla Tomcat guide at http://docs.camunda.org/latest/guides/installation-guide/tomcat/#bpm-platform-install-the-platform-on-a-vanilla-tomcat .

To get engine-rest running, I had to remove all libs in WEB-INF except the Jackson ones

jackson-core-asl-1.9.11.jar
jackson-jaxrs-1.9.11.jar
jackson-mapper-asl-1.9.11.jar

Further, I removed the filter defined for RestEasy in web.xml

  <filter>

      <filter-name>Resteasy</filter-name>

      <filter-class>

          org.jboss.resteasy.plugins.server.servlet.FilterDispatcher

      </filter-class>

      <init-param>

          <param-name>javax.ws.rs.Application</param-name>

          <param-value>org.camunda.bpm.engine.rest.impl.application.DefaultApplication</param-value>

      </init-param>

  </filter>

  <filter-mapping>

      <filter-name>Resteasy</filter-name>

      <url-pattern>/*</url-pattern>

  </filter-mapping>

Then it worked like expected.

Regarding camunda-webapp, i saw when starting up TomEE, the application is initialized by CXF instead of RestEasy, so there may be another culprit.

I'll investigate it this week.

Cheers

Christian

[Christian Lipphardt]

I had a quick look, looks like when I'm following the engine-rest approach I described above, CXF is only initializing one of three jax-rs applications included in camunda-webapp.

[kanschik...@googlemail.com]

Hi Christian,

I tried the following:

First try: I followed the vanilla tomcat guide (which by the way worked perfectly on a vanilla tomcat). Rest engine works without the cockpit, but when both are deployed and used, I get the error messages of my original post.

Second try: As you mentioned, I removed the three jackson jars and changed the web.xml.
Result: There is (at least in 7.0.0-final) a hard dependency on jackson (see https://github.com/camunda/camunda-bpm-platform/blob/7.0.0-Final/engine-rest/src/main/java/org/camunda/bpm/engine/rest/impl/application/DefaultApplication.java#L37-L39).

Therefore I got the following exception:
Caused by: java.lang.NoClassDefFoundError: org/codehaus/jackson/jaxrs/JacksonJsonProvider
at org.camunda.bpm.engine.rest.impl.application.DefaultApplication.getClasses(DefaultApplication.java:74)
at org.apache.openejb.config.AnnotationDeployer$ProcessAnnotatedBeans.deploy(AnnotationDeployer.java:2021)
at org.apache.openejb.config.AnnotationDeployer$ProcessAnnotatedBeans.deploy(AnnotationDeployer.java:1824)
at org.apache.openejb.config.AnnotationDeployer.deploy(AnnotationDeployer.java:355)
at org.apache.openejb.config.ConfigurationFactory$Chain.deploy(ConfigurationFactory.java:396)
at org.apache.openejb.config.ConfigurationFactory.configureApplication(ConfigurationFactory.java:938)
at org.apache.tomee.catalina.TomcatWebAppBuilder.startInternal(TomcatWebAppBuilder.java:1171)
at org.apache.tomee.catalina.TomcatWebAppBuilder.configureStart(TomcatWebAppBuilder.java:1051)
at org.apache.tomee.catalina.GlobalListenerSupport.lifecycleEvent(GlobalListenerSupport.java:127)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5322)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 10 more
Caused by: java.lang.ClassNotFoundException: org.codehaus.jackson.jaxrs.JacksonJsonProvider
at org.apache.openejb.core.TempClassLoader.loadClass(TempClassLoader.java:141)
at org.apache.openejb.core.TempClassLoader.loadClass(TempClassLoader.java:74)


But since starting only the engine without webapp works, I also assume that the problem is somehow linked to the webapp / cxf / jax-rs.

Regards,

Jens.

[Christian Lipphardt]

Hi Jens,

like I wrote you have to keep only the Jackson jars and delete all other (engine-rest).

Cheers

Christian

[kanschik...@googlemail.com]

Just a quick update: the problem is resolved. According to a colleague, the problem was the webapp was not 100% conforming to JEE standards, but I currently don't know the details. The details will follow ;-)

[Christian Lipphardt]

Thanks! Would be nice if you can provide us with your solution.

Cheers

Christian

[thomasl...@gmail.com]

Hi Christian,

as mentioned by my colleague Jens i will provide a solution for this problem.
I've opened an issue in Jira for this. (https://app.camunda.com/jira/browse/CAM-1734)
I will provide the solution via github branch at the end of next week.

Regards,
Thomas