Solucionado
Estou tentando parar e iniciar o tomcat e estou tendo o erro: qual senha insiro aqui?
==== AUTHENTICATING FOR org.freedesktop.systemd1.manage-units ===
Authentication is required to stop 'tomcat8.service'.
Authenticating as: Ubuntu (ubuntu)
Password:ao parar e ao iniciar:
ubuntu@ip-172-31-27-65:/usr/share/tomcat8/bin$ ==== AUTHENTICATING FOR org.freedesktop.systemd1.manage-units ===
Authentication is required to start 'tomcat8.service'.
Authenticating as: Ubuntu (ubuntu)
Password:Resolvido