JavaEE Training Note - Day 11

Tosay’s topic is related to configuration of service in remote Linux server. The target server is an ubuntu server 16.04. Following are some of configuration steps.

Java （Oracle JDK)

Restricted by legal reasons, the oracle JDK is not available in official source of ubuntu. Therefore, most of times, the oracle JDK requires manual steps to configure. However, on ubuntu environmant, there is a machinism that we can use the package from a personal source, which is PPA, Persnal Package Archive. A personal managed source, that can be subscribed and receive package using the general package management tool in ubuntu (that is APT).

The following step is install oracle JDK 8 via the PPA method on ubuntu environment.

1. update the system

   sudo apt-get update && sudo apt-get dist-upgrade

2. register PPA The package has already managed by WebUpd8 team for several years with enough stability.

   sudo add-apt-repository ppa:webupd8team/java

3. Update package list cache

   sudo apt-get update

4. Install Java The oracle-java8-set-default package will install the corresponsding Java version and update the system configration for alternatives to use oracle JDK as default Java version.

   sudo apt-get install oracle-java8-set-default

Tomcat 8.5

A packaged vesion of Apache Tomcat is provided in package source, while it is some kinds of out-of-date. The following steps are used to download leasted release of Tomcat and configure it as a daemon.

1. Download Download the least relese from https://tomcat.apache.org/download-80.cgi and use the wget tool to save in to server.

   wget http://mirrors.koehn.com/apache/tomcat/tomcat-8/v8.5.11/bin/apache-tomcat-8.5.11.tar.gz \
       -O ~/tomcat.tar.gz

2. Create tomcat user and group

   sudo addgroup --system tomcat
   sudo adduser --system --ingroup tomcat tomcat

3. Unpack the package Unpack the tarball and modify the user and group property of the package files.

   tar -xvf ~/tomcat.tar.gz
   sudo mv ~/apache-tomcat-* /home/tomcat/ 
   sudo chown tomcat:tomcat -R /home/tomcat/apache-tomcat-*

4. Use authbind the allow binding to 80 port In Linux/Unix environment, the port with port number less then 1024 are privlidged. To manage binding to these port, the authbnf package is a useful package.

   sudo apt install authbind
   sudo touch /etc/authbind/byport/{443,80}
   sudo chmod 500 /etc/authbind/byport/{443,80}
   sudo chown tomcat:tomcat /etc/authbind/byport/{443,80}

5. Update tomcat server.xml configuration Tomcat configuration file server.xml is used to manage hte port and connectivity of the server and its internal conponents. This file is placed in conf package of root directory of tomcat.

   sudo sed -i 's/8080/80/g' /home/tomcat/apache-tomcat-*/conf/server.xml

This command is to update the following lines:

<!-- original http configuration -->
<Connector port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />
<!-- update port configuration -->
<Connector port="80" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />

1. Configure systemd to use tomcat as daemon

Edit (create) the systemd configuration entry:

sudo vim /etc/systemd/system/tomcat.service

Then add the following content: (use i to insert, ues <esc>:x to save and quit) the JAVA_HOME should pointing to root folder of JDK and the CATALINA_HOME and CATALINA_BASE should update to tomcat path. (with correct version number).

[Unit]
Description=Tomcat Container
After=network.target

[Service]
Type=forking

Environment=JAVA_HOME=/usr/lib/jvm/java-8-oracle
Environment=CATALINA_PID=/home/tomcat/tmp/tomcat.pid
Environment=CATALINA_HOME=/home/tomcat/apache-tomcat-8.5.11
Environment=CATALINA_BASE=/home/tomcat/apache-tomcat-8.5.11

ExecStart=/home/tomcat/apache-tomcat-8.5.11/bin/startup.sh
ExecStop=/home/tomcat/apache-tomcat-8.5.11/bin/shutdown.sh

User=tomcat
Group=tomcat
RestartSec=10
Restart=always

[Install]
WantedBy=multi-user.target

Enable and start the daemon with systemctl tool

sudo systemctl daemon-reload
sudo systemctl enable tomcat.service
sudo systemctl restart tomcat.service