tomcat starts in terminal but not running in browser

If any error occur during tomcat startup time then that tomcat error is not shown on ubuntu terminal. So you need to check log file from following location.

{tomcat path}/logs/catalina.{date}.log

{tomcat path} = tomcat install path.
{date} = log of date.

One of the reason might be, the JAVA_HOME or JRE_HOME not set.
Set JAVA_HOME either in the docker file or on the /etc/bash.bashrc file.

Reference