An example configuration for Tomcat as systemd service. #tomcat #systemd #systemd.service

README-tomcat-as-systemd-service.md

README

Let Tomcat is download and installed under /opt/tomcat. Also, let tomcat be a non-provileged user under which the server will be running.

We assume that we keep server's binaries under /opt/tomcat and we will create a server instance named foo under /var/tomcat/ (carrying its own conf, logs, webapps, work, lib directories). See also https://dzone.com/articles/running-multiple-tomcat.

Create a template service unit file at /etc/systemd/system/[email protected]:

[Unit]
Description=Tomcat - instance %i
After=syslog.target network.target

[Service]
Type=forking

User=tomcat
Group=tomcat

WorkingDirectory=/var/tomcat/%i

Environment="JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64/"
Environment="JAVA_OPTS=-Djava.security.egd=file:///dev/urandom"

Environment="CATALINA_PID=/var/tomcat/%i/run/tomcat.pid"
Environment="CATALINA_BASE=/var/tomcat/%i/"
Environment="CATALINA_HOME=/opt/tomcat/"
Environment="CATALINA_OPTS=-Xms512M -Xmx1024M -server -XX:+UseParallelGC"

ExecStart=/opt/tomcat/bin/startup.sh
ExecStop=/opt/tomcat/bin/shutdown.sh

#RestartSec=10
#Restart=always

[Install]
WantedBy=multi-user.target

Now, we can instantiate a service instance for our foo tomcat instance:

systemctl daemon-reload
systemctl enable [email protected]
systemctl start [email protected]

Addendum.

There is a problem using the ExecStart=/opt/tomcat-9.0.79/bin/catalina.sh run method to start tomcat.

The problem is that the run method outputs to stdout and stderr. It you use catalina.sh start instead, stdout and stderr get redirected to your catalina.out file by the startup script. Using startup.sh calls catalina.sh start so it behaves the same. This redirect does not happen with the run method and so you get no catalina.out file. It is possible to play around with the systemd unit file options StandardOutput=journal, StandardError=inherit and SyslogIdentifier=??? to output to the journal, but then you have to trap the messages in the journal using an rsyslogd configlet (if you use rsyslog) and this becomes more of a pain if you have multiple tomcats and you want multiple catalina.out log files one per tomcat ......... and then its permissions don't follow the tomcats etc.

Bottom line - don't use the run method to start your tomcat with systemd.