Ubuntu environment setup

For example environment, we will use an Ubuntu 24.04 LTS, OpenJDK 21, Tomcat 10, Nginx.

1. Update

Update all Ubuntu packages.

$ sudo apt update
$ sudo apt list --upgradable
$ sudo apt upgrade
$ sudo apt autoremove

2. Setup swap

Create swap and make it permanent.

$ sudo fallocate -l 4G /swapfile
$ sudo chmod 600 /swapfile
$ sudo mkswap /swapfile
$ sudo swapon /swapfile

$ sudo swapon --show

$ echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab

Change swapiness.

$ sudo cat /proc/sys/vm/swappiness
$ sudo echo "vm.swappiness = 10" | sudo tee -a /etc/sysctl.d/99-swappiness.conf
$ sudo sysctl -p
$ sudo sysctl vm.swappiness=10

3. Java Installation

The application requires JDK 21 to be installed.

$ sudo apt install openjdk-21-jdk

4. Installation and configuration of Tomcat

We need a separate user to run Tomcat service and base directory to deploy the application.

$ sudo groupadd timvero
$ sudo useradd -s /bin/false -g timvero -d /opt/pumpkin pumpkin

Now we can install Tomcat and apply base directory.

$ sudo apt install tomcat10-user
$ sudo tomcat10-instance-create -p 8080 -c 8005 /opt/pumpkin

Add Valve to /opt/pumpkin/conf/server.xml.

<Valve className="org.apache.catalina.valves.RemoteIpValve"
    remoteIpHeader="x-forwarded-for"
    protocolHeader="x-forwarded-proto" />

5. Redis sessions

Copy this libraries to /opt/pumpkin/lib/

1. https://mvnrepository.com/artifact/org.redisson/redisson-all

2. https://mvnrepository.com/artifact/org.redisson/redisson-tomcat-10

Add Redisson configuraton file /opt/pumpkin/conf/redisson.yaml

singleServerConfig:
    address: "redis://127.0.0.1:6379"
    database: 1
    password: ___REDIS_PASSWORD___
    connectionMinimumIdleSize: 10
threads: 0
nettyThreads: 0

And add to /opt/pumpkin/conf/context.xml

<Manager className="org.redisson.tomcat.RedissonSessionManager"
    configPath="${catalina.base}/conf/redisson.yaml"
    readMode="REDIS" updateMode="DEFAULT" broadcastSessionEvents="false"
    keyPrefix=""/>

6. Basic application settings

Create the application configuration file /opt/pumpkin/conf/application.properties

#host, port, and database name
dataSource.url=jdbc:postgresql://<host>:<port>/<database>#database username
dataSource.username=
dataSource.password=

application.serverMode=true

application.home=/opt/timvero

7. Application home

Create the application home folder for work and temporary files.

$ sudo mkdir /opt/timvero
$ sudo mkdir /opt/timvero/hbm2ddl/
$ sudo chmod -R 660 /opt/timvero
$ sudo chown -R pumpkin:timvero /opt/timvero

$ sudo chmod -R 774 /opt/pumpkin
$ sudo chown -R pumpkin:timvero /opt/pumpkin

8. Service

Create system service configuration file /etc/systemd/system/pumpkin.service.

[Unit]
Description=Main Timvero Application
After=network.target

[Service]
Type=forking

Environment="JAVA_HOME=/usr/lib/jvm/java-21-openjdk-amd64"

Environment="CATALINA_BASE=/opt/pumpkin"
Environment="CATALINA_HOME=/opt/pumpkin"
Environment="CATALINA_PID=/opt/pumpkin/temp/tomcat.pid"
Environment="CATALINA_OPTS=-server"
Environment="JAVA_OPTS=-Xms512M -Xmx1G -Dspring.config.additional-location=/opt/pumpkin/conf/application.properties"

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

User=pumpkin
Group=timvero
UMask=0007
RestartSec=10
Restart=always

[Install]
WantedBy=multi-user.target

And apply it.

$ sudo systemctl daemon-reload
$ sudo systemctl enable pumpkin.service

9. Database

Create database, user and grant permissions.

CREATE DATABASE pumpkin;
CREATE USER pumpkin WITH ENCRYPTED PASSWORD '******';
ALTER DATABASE pumpkin OWNER TO pumpkin;

10. Proxy configuration

In case of reverse proxy presents the application requires correct headers forwarding. Here is example location for Nginx server.

     # Example proxy configuration
        location / {
                proxy_http_version 1.1;
                proxy_set_header Host $host;

                proxy_set_header x-forwarded-for $remote_addr;
                proxy_set_header x-forwarded-host $host;
                proxy_set_header x-forwarded-proto "https";

                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection "upgrade";
                proxy_set_header Origin $http_origin;

                # Tomcat host and port
                proxy_pass http://127.0.0.1:8080;
        }

11. User for deployment

Create user.

$ sudo adduser --disabled-password deploy
$ sudo usermod -g timvero deploy

Generate new private and public key pair. Save public key to user home ~/.ssh/authorized_keys.

To add service permissions edit /etc/sudoers.d/deploy.

deploy ALL=(ALL) NOPASSWD:/usr/sbin/service pumpkin *

12. Start application

Upload WAR file to folder /opt/pumpkin/webapps and start pumpkin service.