DevOps Classroom Series – 29/Apr/2021

Deploying a Spring boot application to ubuntu

• create a ubuntu vm
• Install jdk 11

sudo apt update
sudo apt install openjdk-11-jdk -y

• Downlod the spring petclinic application Refer Here and deploy as a linux service Refer Here

wget https://storage.googleapis.com/qtreferenceapplications/spring-petclinic-2.4.2.jar
sudo useradd bootuser
sudo mkdir /usr/share/petclinic
sudo cp spring-petclinic-2.4.2.jar /usr/share/petclinic/spring-petclinic-2.4.2.jar
sudo chown bootuser:bootuser /usr/share/petclinic/spring-petclinic-2.4.2.jar
sudo chmod 500 /usr/share/petclinic/spring-petclinic-2.4.2.jar

• Now create a file in /etc/systemd/system/springpetclinic.service with the following content

[Unit]
Description=A Spring Boot application
After=syslog.target

[Service]
User=bootuser
ExecStart=java -jar /usr/share/springpetclinic/spring-petclinic-2.4.2.jar
SuccessExitStatus=143
Restart=always
StandardOutput=append:/var/log/petclinic.log
StandardError=append:/var/log/petclinicerrors.log


[Install]
WantedBy=multi-user.target

• Now reload the system daemon and start the spring petclinic

sudo systemctl daemon-reload
sudo systemctl start springpetclinic.service
 sudo systemctl status springpetclinic.service

• The logs of this application are generated in
  • /var/log/petclinic.log
  • /var/log/petclinicerrors.log
• Individual log

#log
2021-04-29 02:34:01.020 DEBUG 353 --- [nio-8080-exec-9] o.s.web.servlet.DispatcherServlet        : Completed 200 OK
# grok patterns
%{SYSLOGTIMESTAMP : datetime}%{SPACE}%{WORD:application}%{SPACE}(?<thread>java\[\d+\]:\s)%{TIMESTAMP_ISO8601}%{SPACE}%{LOGLEVEL:level}%{SPACE}(?<thread_info>\d+\s+---\s\[[\b\w*\d*-]*\]\s)%{JAVACLASS:class}%{SPACE}%{GREEDYDATA:logmessage}

• Now install and configure filebeat to send the logs from the above two files to logstash running on 5045 port
• edit the filebeat.yml file at /etc/filebeat/filebeat.yml
• Now login into vm with logstash and create a new file /etc/logstash/conf.d/petclinic.conf

input {
    beats  {
        host => "10.128.15.198"
        port => 5045
    }
}
filter{
    grok {
        match => {"message" => "%{TIMESTAMP_ISO8601}%{SPACE}%{LOGLEVEL:level}%{SPACE}(?<thread_info>\d+\s+---\s\[[\b\w*\d*-]*\]\s)%{JAVACLASS:class}%{SPACE}%{GREEDYDATA:logmessage}"}
    }
}
output {
	stdout {
		codec => rubydebug
	}
    elasticsearch {
        hosts => "http://10.128.15.198:9200"
        index => "springpetclinic-%{+YYYY.MM.dd}"
    }
}

• Start the logstash service

sudo serivce 

• Once the data is arrived create a index pattern in kibana
• Now use kql to search the logs Refer Here