Ansible contd..

Tomcat10 on ubuntu

• Remaining manual steps are
• create a service file with the following contents at /etc/systemd/system/tomcat.service

[Unit]
Description=Apache Tomcat 10 Web Application Container
After=network.target

[Service]
Type=forking

User=tomcat
Group=tomcat

Environment="JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64"
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=/opt/tomcat/bin/shutdown.sh

[Install]
WantedBy=multi-user.target

• Now enable and start tomcat

sudo systemctl daemon-reload
sudo systemctl start tomcat
sudo systemctl enable tomcat

• Refer Here for the changes done to create a tomcat service by copying a static file.
  

Problems to be fixed

• Re-execution of playbook ideally shouldn’t change anything if there are no changes.
• But in our case it does
  
• To fix this lets understand
  • the concept of handler in ansible.
  • conditionals
• Handler is a special kind of task that runs only when notified. Primary purposed is to trigger an action only on change.
• To understand conditionals we need to know about ansible facts.

Ansible facts

• Refer Here for official docs
• Facts are information of remote nodes
• By default facts are gather at the beginning of every playbook execution
• There is a module called as setup which gathers the facts
• Refer Here for a simple changes to view facts
• Refer Here for sample output