Day: December 25, 2020
How to add a custom tomcat installation to SystemD with ansible.
Okay so say you have a custom install of tomcat and java, which is what a lot of people do because java update and tomcat updates can bring things down. So things need to be tested before updates and standard patch cycles can end up affecting the environment.
But you want to handle the startup and stopping via systemd to be able to get status outputs and let system handle the service on reboots. This is how to do it slick.
Ansible Setup:
Role:
Setup the new role:
Main.yml
===========================================
Note: this will install the redhat tomcat version of tomcat. Do not worry we are not going to be using this tomcat. This is just so redhat automatically setups all the needed services and locations. We will then update the SystemD config for tomcat to use the custom version.
– name: Install the latest version of tomcat
package:
name: tomcat
state: latest
Note: This symlink is important as tomcat default install by redhat is inside /opt/tomcat. Update the src to the custom location of your tomcat
– name: Create symbolic link for “tomcat” in /opt
file:
src: /custom/install/tomcat
path: /opt/tomcat
force: yes
state: link
Note: This will enable tomcat to start up on reboot
– name: Enable tomcat service on startup
shell: systemctl enable tomcat
Note: This is the tomcat systemd service file that systemd uses for the default install. We are going to empty.
– name: Null tomcat.service file
shell: “>/etc/systemd/system/tomcat.service“
Note: We are now going to add our custom block for tomcat into the tomcat.service file we just emptied above using the blockinfle module. This means that this whole section will also be managed by ansible as well. Make sure you adjust the java_home if your java isn’t location inside tomcat. Along with the user,group,umask for to your custom tomcat.
– name: Edit tomcat.service for systemd
blockinfile:
dest: /etc/systemd/system/tomcat.service
insertafter:
block: |
[Unit]
Description=Apache Tomcat Web Application Container
After=syslog.target network.target
[Service]
Type=forking
Environment=JAVA_HOME=/opt/tomcat
Environment=CATALINA_PID=/opt/tomcat/temp/tomcat.pid
Environment=CATALINA_HOME=/opt/tomcat
Environment=CATALINA_BASE=/opt/tomcat
Environment=’CATALINA_OPTS=-Xms512M -Xmx1024M -server –XX:+UseParallelGC‘
Environment=’JAVA_OPTS=-Djava.awt.headless=true –Djava.security.egd=file:/dev/./urandom‘
ExecStart=/opt/tomcat/bin/startup.sh
ExecStop=/bin/kill -15 $MAINPID
User=tomcat
Group=tomcat
UMask=
RestartSec=10
Restart=always
[Install]
WantedBy=multi-user.target
Note: This will then reload the custom tomcat via systemd
– name: Start tomcat service with Systemd
systemd:
name: tomcat
daemon_reload: yes
Note: This will then check to see if the new tomcat is service running and out to the ansible playbook log.
– name: get service facts
service_facts:
– name: Check to see if tomcat is running
debug:
var: ansible_facts.services[“tomcat.service“]
Ansibe playbook log:
[root@nickansible]# ansible-playbook –i inventory/DEV/hosts justtomcatrole.yml –limit ‘nicktestvm‘ -k
SSH password:
PLAY [all] ************************************************************************************************************************************************************************************************
TASK [AddTomCatSystemD : Create symbolic link for “tomcat” in /opt] ***************************************************************************************************************************************
changed: nicktestvm]
TASK [AddTomCatSystemD : Enable tomcat service on startup] ************************************************************************************************************************************************
changed: nicktestvm]
TASK [AddTomCatSystemD : Null tomcat.service file] ********************************************************************************************************************************************************
changed: nicktestvm]
TASK [AddTomCatSystemD : Edit tomcat.service for systemd] *************************************************************************************************************************************************
changed: nicktestvm]
TASK [AddTomCatSystemD : Start tomcat service with Systemd] ***********************************************************************************************************************************************
ok: nicktestvm]
TASK [AddTomCatSystemD : get service facts] ***************************************************************************************************************************************************************
ok: nicktestvm]
TASK [AddTomCatSystemD : Check to see if tomcat is running] ***********************************************************************************************************************************************
ok: nicktestvm] => {
“ansible_facts.services[\”tomcat.service\”]”: {
“name”: “tomcat.service“,
“source”: “systemd“,
“state”: “running”,
“status”: “enabled”
}
}
PLAY RECAP ************************************************************************************************************************************************************************************************
nicktestvm : ok=7 changed=4 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
==========================
[root@nicktestvm ~]# cat /etc/systemd/system/tomcat.service
# BEGIN ANSIBLE MANAGED BLOCK
[Unit]
Description=Apache Tomcat Web Application Container
After=syslog.target network.target
[Service]
Type=forking
Environment=JAVA_HOME=/opt/tomcat
Environment=CATALINA_PID=/opt/tomcat/temp/tomcat.pid
Environment=CATALINA_HOME=/opt/tomcat
Environment=CATALINA_BASE=/opt/tomcat
Environment=’CATALINA_OPTS=-Xms512M -Xmx1024M -server -XX:+UseParallelGC’
Environment=’JAVA_OPTS=-Djava.awt.headless=true -Djava.security.egd=file:/dev/./urandom’
ExecStart=/opt/tomcat/bin/startup.sh
ExecStop=/bin/kill -15 $MAINPID
User=tomcat
Group=tomcat
UMask=0028
RestartSec=10
Restart=always
[Install]
WantedBy=multi-user.target
# END ANSIBLE MANAGED BLOCK
SystemD Status:
root@nicktestvm ~]# systemctl status tomcat
● tomcat.service – Apache Tomcat Web Application Container
Loaded: loaded (/etc/systemd/system/tomcat.service; enabled; vendor preset: disabled)
Active: active (running) since Thu 2020-12-24 05:11:21 GMT; 21h ago
Process: 6333 ExecStop=/bin/kill -15 $MAINPID (code=exited, status=0/SUCCESS)
Process: 6353 ExecStart=/opt/tomcat/bin/startup.sh (code=exited, status=0/SUCCESS)
Main PID: 6363 (java)
CGroup: /system.slice/tomcat.service
└─6363 /usr/local/java/java -Djava.util.logging.config.file=/opt/tomcat/conf/logging.properties -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -server -Xms1…
Dec 24 05:11:21 nicktestvm systemd[1]: Starting Apache Tomcat Web Application Container…
Dec 24 05:11:21 nicktestvm startup.sh[6353]: Existing PID file found during start.
Dec 24 05:11:21 nicktestvm startup.sh[6353]: Removing/clearing stale PID file.
Dec 24 05:11:21 nicktestvm systemd[1]: Started Apache Tomcat Web Application Container.