I installed tomcat6 on lucid using apt-get. All working.

I installed tomcat-admin. Not working.

I amended the /etc/tomcat6/tomcat-users.xml file to uncomment the users and roles (from the default) to be like the following:

<role rolename="tomcat"/>
<role rolename="role1"/>
<user username="tomcat" password="password" roles="tomcat"/>
<user username="both" password="password" roles="tomcat,role1"/>
<user username="role1" password="password" roles="role1"/>

This still didn't work.

Then from the following page I added.

<role rolename="manager"/>
<user username="admin" password="secret" roles="manager"/>

then it worked.

Why doesn't this occur as part of the install? (Why isn't this in the Ubuntu Manual on Tomcat ?)