Handle exception from Web server startup

[Ashish123gs]

I noticed that we don't handle the error thrown from Web server startup.
One of the common problem can be the 'port in use' when Web server starts up.

The cruise control app will start and continue to run but the http API will be inaccessible.
This can be misleading and can cause problems when we run multiple daemons on same host.
someone can accidently use a different http api.

ex error -

//..//

[2022-02-22 15:04:16,091] ERROR Uncaught exception on thread Thread[main,5,main] (com.linkedin.kafka.cruisecontrol.KafkaCruiseControlMain)
java.io.IOException: Failed to bind to /myServer:myPort
at org.eclipse.jetty.server.ServerConnector.openAcceptChannel(ServerConnector.java:349) ~[jetty-server-9.4.42.v20210604.jar:9.4.42.v20210604]
at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:310) ~[jetty-server-9.4.42.v20210604.jar:9.4.42.v20210604]
at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80) ~[jetty-server-9.4.42.v20210604.jar:9.4.42.v20210604]
at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:234) ~[jetty-server-9.4.42.v20210604.jar:9.4.42.v20210604]
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73) ~[jetty-util-9.4.42.v20210604.jar:9.4.42.v20210604]
at org.eclipse.jetty.server.Server.doStart(Server.java:401) ~[jetty-server-9.4.42.v20210604.jar:9.4.42.v20210604]
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:73) ~[jetty-util-9.4.42.v20210604.jar:9.4.42.v20210604]
at com.linkedin.kafka.cruisecontrol.KafkaCruiseControlApp.start(KafkaCruiseControlApp.java:66) ~[cruise-control.jar:?]
at com.linkedin.kafka.cruisecontrol.KafkaCruiseControlMain.main(KafkaCruiseControlMain.java:40) ~[cruise-control.jar:?]
Caused by: java.net.BindException: Address already in use
at sun.nio.ch.Net.bind0(Native Method) ~[?:1.8.0_202]
at sun.nio.ch.Net.bind(Net.java:433) ~[?:1.8.0_202]
at sun.nio.ch.Net.bind(Net.java:425) ~[?:1.8.0_202]
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223) ~[?:1.8.0_202]
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74) ~[?:1.8.0_202]
at org.eclipse.jetty.server.ServerConnector.openAcceptChannel(ServerConnector.java:344) ~[jetty-server-9.4.42.v20210604.jar:9.4.42.v20210604]
... 8 more

//..//

[Ashish123gs]

may be we handle the error in KafkaCruiseControlApp.java

line 66

void start() throws Exception {
_kafkaCruiseControl.startUp();
try{
_server.start();
} catch ( Exception e)
{
"failed to start server..exiting now"
System.exit(1);
}
printStartupInfo();
}