1. Check if the correct version of Java is installed

JAVA is required for Tomcat to work, CentOS 7 comes with JAVA 7 witch is the needed version. To check if it is installed run:

# java -version
java version "1.7.0_55"
OpenJDK Runtime Environment (rhel-2.4.7.2.el7_0-x86_64 u55-b13)
OpenJDK 64-Bit Server VM (build 24.51-b03, mixed mode)

In case java is not installed on your system or you have version 1.6.x, you can install it by running:

# yum install java-1.7.0-openjdk.x86_64 java-1.7.0-openjdk-devel

2. Download Tomcat

You can find the latest version of  Tomcat at its download page. You can download it with wget and extract it with tar like this:

# cd /usr/share
# wget http://archive.apache.org/dist/tomcat/tomcat-8/v8.0.9/bin/apache-tomcat-8.0.9.tar.gz
# tar zxvf apache-tomcat-8.0.9.tar.gz

3. Add tomcat user & group

As it is not recommended to run Tomcat as root we will need to create an unprivileged user for it and set the apropiate owner of the tomcat folder:

# groupadd tomcat
# useradd -g tomcat -s /bin/bash -d /usr/share/apache-tomcat-8.0.9 tomcat
# chown -Rf tomcat.tomcat /usr/share/apache-tomcat-8.0.9/

4. Running Tomcat

To start tomcat we will first need to switch to the unprivileged user with:

# su – tomcat

And starting tomcat is as easy as running its startup script like this:

$ cd bin
$ ./startup.sh

The output should look like:

Using CATALINA_BASE: /usr/share/apache-tomcat-8.0.9
Using CATALINA_HOME: /usr/share/apache-tomcat-8.0.9
Using CATALINA_TMPDIR: /usr/share/apache-tomcat-8.0.9/temp
Using JRE_HOME: /
Using CLASSPATH: /usr/share/apache-tomcat-8.0.9/bin/bootstrap.jar:/usr/share/apache-tomcat-8.0.9/bin/tomcat-juli.jar
Tomcat started.

You should now be able to access it with a browser by either accessing http://localhost:8080 if this is a local computer or http://SERVER-IP:8080 if you are running it on a remote host.

To shutdown Tomcat you can simply run the shutdown script in the same folder like this:

$ ./shutdown.sh

5. Setup user accounts

Finally you have to configure Tomcat users so they can access admin/manager sections. You can do this by adding the users in the conf/tomcat-users.xml file with your favorite text editor. Add this text to the file:

<user username="manager" password="PASSWORD" roles="manager-gui" />

<user username="admin" password="PASSWORD" roles="manager-gui,admin-gui" />

6. Running Multiple Instances of Tomcat (Optional)

Sometimes you need to run more than one instance of Tomcat on the same server. To do this, as root, go back to the /usr/share directory where you first downloaded tomcat and extract it again in a different folder like this:

# cd /usr/share
# mkdir apache-tomcat-2
# tar zxvf apache-tomcat-8.0.9.tar.gz -C apache-tomcat-2 --strip-components 1
# chown -Rf tomcat.tomcat /usr/share/apache-tomcat-2/

Now we need to open the config/server.xml file in the new installation folder and change the port numbers like this:

The shutdown port from:

<Server port="8005" shutdown="SHUTDOWN">

to:

<Server port="8006" shutdown="SHUTDOWN">

The connector port from:

<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />

to:

<Connector port="8081" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />

And the AJP port from:

    <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />

to:

<Connector port="8010" protocol="AJP/1.3" redirectPort="8443" />

Now you can just switch back to the tomcat user and start the second instance like this:

# su - tomcat
$ cd /usr/share/apache-tomcat-2/bin/
$ ./startup.sh
Using CATALINA_BASE: /usr/share/apache-tomcat-2
Using CATALINA_HOME: /usr/share/apache-tomcat-2
Using CATALINA_TMPDIR: /usr/share/apache-tomcat-2/temp
Using JRE_HOME: /
Using CLASSPATH: /usr/share/apache-tomcat-2/bin/bootstrap.jar:/usr/share/apache-tomcat-2/bin/tomcat-juli.jar
Tomcat started.

You can now access the new instance of tomcat with your browser at http://localhost:8081/

Congratulation you now have Tomcat installed and ready to use!

Tomcat configurations

How to Install Tomcat on Linux ?

# Download and Install JAVA

Download j2sdk-<version> from Sun Download center http://developers.sun.com/downloads/

# chmod +x j2sdk-1_4_2_09-linux-i586.bin
# ./j2sdk-1_4_2_09-linux-i586.bin

Now set java home path

# vi .bash_profile

JAVA_HOME=/usr/local/j2sdk

Now Check if Java is installed on the server using command java -version

[root@map ~]# java -version
java version “1.6.0_07?
Java(TM) SE Runtime Environment (build 1.6.0_07-b06)
Java HotSpot(TM) Client VM (build 10.0-b23, mixed mode, sharing)

# Download Tomcat

Now Download Tomcat from Apache Website and extract it

http://tomcat.apache.org/download-55.cgi

# cd /usr/local/
#wget http://www.poolsaboveground.com/apache/tomcat/tomcat-6/v6.0.18/bin/apache-tomcat-6.0.18.tar.gz
# tar -zxvf apache-tomcat-6.0.18.tar.gz

Create Symlink for the Tomcat Folder

# ln -s /usr/local/apache-tomcat-6.0.18 /usr/local/apache/tomcat

# Install Tomcat

# cd apache-tomcat-6.0.18
# cd bin
# tar xvfz jsvc.tar.gz
# cd jsvc-src
# chmod +x configure
# ./configure
# make
# cp jsvc ..
# cd ..

Now set Cataline home path

# vi .bash_profile

CATALINA_HOME=/usr/loca/tomcat

JAVA=/usr/loca/j2sdk/bin

Save and exit

# Type following commands

# export JAVA_HOME=/usr/local/j2sdk

# export JAVA=/usr/local/j2sdk/bin

# export CATALINA=/usr/local/tomcat

# Start Tomcat

Use Following script to start Tomcat Service on the Server

# /usr/local/apache/tomcat/bin/startup.sh

# Running Tomcat as non root user

Due to security reasons always run tomcat as non-root user i.e. tomcat. To run it as tomcat first you will have to change the ownership of the tomcat folder

# chown -R tomcat.tomcat /usr/local/apache-tomcat-6.0.18

Now Tomcat can be stopped and started under user tomcat using following commands:

# su -l tomcat -c /usr/local/apache/tomcat/bin/startup.sh
# su -l tomcat -c /usr/local/apache/tomcat/bin/shutdown.sh

# Test Tomcat installation

open a browser and browse website http://xx.xx.xx.xx:8080 where xx.xx.xx.xx will be your Server IP and If you get Tomcat page than Tomcat has been installed properly on the Server.

# Creating Script to start, stop and restart Tomcat

The above installation step will not create tomcat service so that user can restart tomcat using command service tomcat restart. Create a new file in /etc/init.d as tomcat and copy following contenents into it.
# vi /etc/init.d/tomcat

#!/bin/bash

#
# Startup script for Tomcat
#
# chkconfig: 345 84 16
# description: Tomcat jakarta JSP server
# Necessary environment variables
export CATALINA_HOME=”/usr/local/tomcat”
if [ ! -f $CATALINA_HOME/bin/catalina.sh ]
then
echo “Tomcat not available…”
exit
fi

start() {
echo -n -e ‘\E[0;0m'"\033[1;32mStarting Tomcat: \033[0m \n"
su -l tomcat -c $CATALINA_HOME/bin/startup.sh
echo
touch /var/lock/subsys/tomcatd
sleep 3
}

stop() {
echo -n -e '\E[0;0m'"\033[1;31mShutting down Tomcat: \033[m \n"
su -l tomcat -c $CATALINA_HOME/bin/shutdown.sh
rm -f /var/lock/subsys/tomcatd
echo
}

status() {
ps ax --width=1000 | grep "[o]rg.apache.catalina.startup.Bootstrap start” | awk ‘{printf $1 ” “}’ | wc | awk ‘{print $2}’ > /tmp/tomcat_process_count.txt
read line < /tmp/tomcat_process_count.txt
if [ $line -gt 0 ]; then
echo -n “tomcatd ( pid ”
ps ax –width=1000 | grep “[o]rg.apache.catalina.startup.Bootstrap start” | awk ‘{printf $1 ” “}’
echo -n “) is running…”
echo
else
echo “Tomcat is stopped”
fi
}

case “$1? in
start)
start
;;
stop)
stop
;;
restart)
stop
sleep 3
start
;;
status)
status
;;
*)
echo “Usage: tomcatd {start|stop|restart|status}”
exit 1
esac

Now save and exit from the file. Now assign executable permission to this file

# chown 755 /etc/init.d/tomcat

Enable it for all the Run-levels

# chkconfig –add tomcat
# chkconfig tomcat on

Now you can restart tomcat service using following commands.

# service tomcat restart <<< To restart tomcat
# service tomcat stop <<< To stop Tomcat
# service tomcat start <<< To start Tomcat
# service tomcat Status <<< to check the status of Tomcat

Now you have successfully installed Tomcat.

Tomcat with Apache Integration on Linux server

# Installing and configuring mod_jk

To make connection between Tomcat and Apache, you will need to download and install mod_jk connector.

I chose to download the current source from the Apache archives:- http://archive.apache.org/dist/jakarta/tomcat-connectors/jk/source/jk-1.2.15/

[root@map007 /]# cd /usr/local

[root@map007 local]# wget http://archive.apache.org/dist/jakarta/tomcat-connectors/jk/source/jk-1.2.15/jakarta-tomcat-connectors-1.2.15-src.tar.gz

[root@map007 local]# tar -zxvf jakarta-tomcat-connectors-1.2.15-src.tar.gz

Change to the /usr/local/jakarta-tomcat-connectors-1.2.15-src/jk/native directory.

[root@map007 local]# cd jakarta-tomcat-connectors-1.2.15-src/jk/native

Now you are ready to create the custom configure file for your system. Execute the following:

[root@map007 local]# ./buildconf.sh

[root@map007 local]# ./configure –with-apxs=/usr/bin/apxs2

Now build the mod_jk with the following:

[root@map007 local]# make

Finally, if you were successful with the previous commands, copy the newly created mod_jk.soto your Apache2 modules directory. My modules were located at /usr/lib/apache2/modules.

[root@map007 /]# cp /usr/src/jakarta-tomcat-connectors-1.2.15-src/jk/native/apache-2.0/mod_jk.so /usr/lib/apache2/modules

# Configuring Tomcat and Apache

[root@map007 /]# vi /etc/apache2/workers.properties

workers.tomcat_home=/usr/lib/apache-tomcat workers.java_home=/usr/lib/jdk ps=/ worker.list=worker1 worker.default.port=8009 worker.default.host=localhost worker.default.type=ajp13 worker.default.lbfactor=1

# Save and close the file.
# Now you have to configure httpd.conf file and following lines.

[root@map007 /]# vi /etc/apache2/httpd.conf

LoadModule jk_module /usr/lib/apache2/modules/mod_jk.so # Where to find workers.properties JkWorkersFile /etc/apache2/workers.properties # Where to put jk logs JkLogFile /var/log/apache2/mod_jk.log # Set the jk log level [debug/error/info] JkLogLevel info # Select the log format JkLogStampFormat “[%a %b %d %H:%M:%S %Y] “

Save and close the file.

Now a final security point.

[root@map007 /]# chown -R tomcat:tomcat /usr/lib/apache-tomcat-5.5.16

# Now restart the Tomcat.

[root@map007 /]# cd /usr/local/tomcat/bin

[root@map007 bin]# ./shutdown.sh
[root@map007 bin]# ./startup.sh

And restart Apache:

[root@map007 /]# /etc/init.d/apache2 restart

You have Done all the Configurations.

Note :- Start Tomcat first: Always start Tomcat first and then start Apache.

References and paths:

Tomcat conf:

/usr/lib/apache-tomcat/conf/server.xml

Apache modules:

/usr/lib/apache2/modules

Apache conf:

/etc/apache2/workers.properties
/etc/apache2/httpd.conf

Tomcat stop and start:

cd /usr/local/apache-tomcat/bin
./shutdown.sh
./startup.sh

Apache2:

/etc/init.d/apache2 restart
/etc/init.d/apache2 stop
/etc/init.d/apache2 start