Tomcat indicates "FAIL" even though it seems to be working

Question

I installed Tomcat8 on Debian Jessie using apt-get in a Docker file. I then sudo service tomcat8 start.

This results in this error:

[FAIL] Starting Tomcat servlet engine: tomcat8 failed!

However, it actually seems to be working, because I can successfully connect via localhost to the default tomcat homepage. (I've verified I'm not connecting to a cached copy).

When I look at the catalina.out log in /var/lib/tomcat8/logs, I see no errors:

May 06, 2017 3:37:26 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /var/lib/tomcat8/webapps/ROOT
May 06, 2017 3:37:27 PM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that wer
scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
May 06, 2017 3:37:27 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory /var/lib/tomcat8/webapps/ROOT has finished in 924 ms
May 06, 2017 3:37:27 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8080"]
May 06, 2017 3:37:27 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 967 ms

I'd like to figure out the cause of this FAIL message.

Answer 1

It may cause because of misloading some class which are default classes for docker runtime. This may occur when you use default tomcat docker file. When you see the admin page of Tomcat, it is working don't worry. Also you can enable debug logging from Catalina conf file to see missing class information in detailed logs.