Tomcat installation of Camunda & REST API - cannot start REST API

Camunda 7 Topics Discussion & Questions
21

@Niall @rob2universe I started over and retraced my steps.

Something I think I missed initially was this step. When I set it, this is the error I get and Tomcat refuses to start:

18-Feb-2020 15:33:26.333 SEVERE [main] org.apache.tomcat.util.digester.Digester.startElement Begin event threw exception
	java.lang.ClassNotFoundException: org.camunda.bpm.container.impl.tomcat.TomcatBpmPlatformBootstrap
		at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:471)
		at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:588)
		at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
		at org.apache.tomcat.util.digester.ObjectCreateRule.begin(ObjectCreateRule.java:116)
		at org.apache.tomcat.util.digester.Digester.startElement(Digester.java:1232)

Does that maybe help indicate where the problem is?
This is with https://app.camunda.com/nexus/repository/public/org/camunda/bpm/webapp/camunda-webapp-tomcat/7.12.0/camunda-webapp-tomcat-7.12.0.war deployed in Tomcat 8.5 on Debian Stretch.

The same problem is present when using https://app.camunda.com/nexus/repository/public/org/camunda/bpm/webapp/camunda-webapp-tomcat-standalone/7.12.0/camunda-webapp-tomcat-standalone-7.12.0.war (the standalone version)

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Hi @danny_xneelo,

you and @rob2universe mixed two different approaches to run the camunda engine.

Your approach is the embedded engine, here included in a web archive running on a servlet engine: https://docs.camunda.org/manual/7.5/introduction/architecture/#embedded-process-engine.

rob recommended the container managed engine with a installed engine in the tomcat lib folder: https://docs.camunda.org/manual/7.5/introduction/architecture/#shared-container-managed-process-engine.

In the moment the engine-rest.war requires a shared engine installation. That’s the reason why you could not start it sucessfully.

And there is no stand-alone rest implementation available right now.

The most easy way to create one would be to create a spring boot project with the camunda-bpm-spring-boot-starter-rest dependency only. You can easliy create it at https://start.camunda.com/.

Hope this helps, Ingo

23

@Ingo_Richtsmeier as always, thanks so much for your help!

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@Ingo_Richtsmeier I can confirm that this works very nicely!

One thing I stumbled on, and maybe this is obvious to longtime users of Spring, but I had to follow https://docs.spring.io/spring-boot/docs/current/reference/html/howto.html#howto-traditional-deployment in order to deploy the built WAR file on Tomcat.

You guys rock

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