Created attachment 1177703 [details]
Proposed fix which works for us.

Description of problem:
This is an upstream bug in upcoming jetty 9.4.0. Caused by this refactoring:
https://github.com/eclipse/jetty.project/commit/a311c8bde171551a57ff28c04851a3b53acfc1e0

Version-Release number of selected component (if applicable):
$ rpm -q jetty-server
jetty-server-9.4.0-0.2.M0.fc25.noarch
$ rpm -q thermostat
thermostat-1.6.0-1.fc25.x86_64

How reproducible:
100%

Steps to Reproduce:
1. dnf install thermostat-webapp (A mock setup will do too)
2. echo -e 'yes\nm\nm\nm\nc\nc\nc\na\na\na' | thermostat setup -c
3. thermostat web-storage-service

Actual results:
starting storage server...
server listening on ip: mongodb://127.0.0.1:27518
log file is here: /root/.thermostat-1.6/logs/db.log
pid: 8285
2016-07-08 15:01:52.035:INFO::Thread-3: Logging initialized @1374ms
2016-07-08 15:01:52.083:INFO:oejs.Server:Thread-3: jetty-9.4.0.M0
2016-07-08 15:01:52.083:WARN:oejs.Server:Thread-3: THIS IS NOT A STABLE RELEASE! DO NOT USE IN PRODUCTION!
2016-07-08 15:01:52.083:WARN:oejs.Server:Thread-3: Download a stable release from http://download.eclipse.org/jetty/
2016-07-08 15:01:52.092:WARN:oejw.WebAppContext:Thread-3: Failed startup of context o.e.j.w.WebAppContext@6cdce5ed{/thermostat/storage,null,null}{/usr/share/thermostat/webapp}
java.lang.ClassNotFoundException: org.eclipse.jetty.webapp.WebInfConfiguration
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        at org.eclipse.jetty.util.Loader.loadClass(Loader.java:65)
        at org.eclipse.jetty.webapp.WebAppContext.loadConfigurations(WebAppContext.java:931)
        at org.eclipse.jetty.webapp.WebAppContext.preConfigure(WebAppContext.java:451)
        at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:520)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
        at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
        at org.eclipse.jetty.server.Server.start(Server.java:437)
        at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:106)
        at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:93)
        at org.eclipse.jetty.server.Server.doStart(Server.java:404)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
        at com.redhat.thermostat.web.endpoint.internal.JettyContainerLauncher.doStartContainerAndDeployWar(JettyContainerLauncher.java:214)
        at com.redhat.thermostat.web.endpoint.internal.JettyContainerLauncher.startContainerAndDeployWar(JettyContainerLauncher.java:125)
        at com.redhat.thermostat.web.endpoint.internal.JettyContainerLauncher.access$000(JettyContainerLauncher.java:77)
        at com.redhat.thermostat.web.endpoint.internal.JettyContainerLauncher$1.run(JettyContainerLauncher.java:99)
        at java.lang.Thread.run(Thread.java:745)
server shutdown complete: /root/.thermostat-1.6/data/db
log file is here: /root/.thermostat-1.6/logs/db.log
Failed to start embedded jetty instance

Expected results:
No ClassNotFoundException and successful startup.

Additional info:
This is likely only reproducible when jetty is being started within an OSGi environment. Such is the case for "thermostat web-storage-service".

Note that the code in Loader around line 65 looks like this:

    @SuppressWarnings("rawtypes")
    public static Class loadClass(String name)
        throws ClassNotFoundException
    {
        ClassLoader loader=Thread.currentThread().getContextClassLoader();
        return (loader==null ) ? Class.forName(name) : loader.loadClass(name);
    }

loader in this context points to the app class loader which booted up the OSGi framework. However, the OSGi bundle jetty-webapp was loaded as a bundle and thus, classes inside it will get loaded with the bundles class loader. Then TCCL won't see the relevant config classes in the webapp bundle whereas the bundle class loader would see it.