How do I quickly setup Tomcat server with Java web application on Linux (Debian)?

Question

I was recently setting up a web application running on Tomcat on Windows. What I had to do was the following:

• Unpack Tomcat in any folder I wanted
• Copy folder with my web application in ./webapps (shown relative to tomcat root)
• Set up JRE path in some configuration file for Tomcat
• Run startup.bat - this produced console window with useful debug output

The Linux case seems to be quite different. After install performed typically through apt, tomcat was already running. It also occupies vast number of different folders across filesystem. The server was started automatically, java or not (I actually don't have Java yet as far as I know) so there's no console output. There must be folder with logs somewhere though.

So my question is how to do with Tomcat what I did on windows. I will need to reproduce that approach, or even automate it. It would actually great if I could make batch installer that would setup Tomcat and my web application - but that's not the question.

Answer 1

Automating Deployment of Tomcat

Installation of Tomcat out of the box on linux, or using apt or your package manager of choice is easy; but as you noted it's difficult to know where everything is and what's configured.

I've found the MOST configurable way to automate Tomcat installation on Linux is by using Chef. The ChefDK can be installed, and then using the Tomcat Cookbook for Chef you can configure and deploy chef again and again!

The advantage of installing Tomcat with Chef is a consistent installation of Tomcat in a manner that is standard, supportable, and in-line with the Tomcat documentation for installation on Linux.

Java pre-requisite

The Tomcat cookbook doesn't install Java, so generally I combine the Java Cookbook to automate the installation of your JRE with Tomcat.

Chef Role to install Tomcat

Below is an example Chef Role I have used to deploy JRE and then Tomcat to a linux box.

• The main two steps that install JRE then Tomcat are in the run_list section of the JSON file
• The override_attributes section of the Chef role sets the attributes for the Java and Tomcat recipes.

{
  "name": "java-appserver-small",
  "default_attributes": {},
  "override_attributes": {
    "java": {
      "jdk_version": "7"
    },
    "oracle": {
      "accept_oracle_download_terms": true
    },
    "tomcat": {
      "java_options": "${JAVA_OPTS} -Djava.awt.headless=true -Dfile.encoding=UTF-8 -server -Xms512m -Xmx3g -XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=256m -XX:MaxPermSize=512m -XX:+DisableExplicitGC -XX:+CMSClassUnloadingEnabled"
    }
  },
  "json_class": "Chef::Role",
  "description": "Role for Java Apps Servers using OpenJDK7 - 15GB Memory",
  "chef_type": "role",
  "run_list": [
    "recipe[java]",
    "recipe[tomcat]"
  ]
}

It's a little bit of a learning curve, but once you know how to automate anything on linux with chef - it's a great start to rapid re-deployment and automation of anything you can imagine.

Automating deployment of an Application (WAR)

You can add a third recipe to your Chef role that will deploy an application on Tomcat. Generally Tomcat can be configured to auto-unpack and deploy a WAR file.

Modify the run_list in the role to include another recipe:

"run_list": [
  "recipe[java]",
  "recipe[tomcat]",
  "recipe[app-deploy]"
]

Deploy WAR from local file on linux instance

The recipe chef will use app-deploy is a set of instructions to copy a pre-defined WAR file to the Tomcat webapps directory. In the below recipe example, the WAR file path is defined in a from a separate attribute file, but you could hard code the location to copy from as well.

#
# Cookbook Name:: myChefCookbook
# Recipe:: app-deploy
#
# This recipe only installs the application.
# Base app server is setup via the java app server role.
#

# Copy WAR to webapps for auto-deployment
execute "cp #{node['myappfile']} /var/lib/tomcat/webapps/" do
  action :run
  not_if { File.exist?("/var/lib/tomcat/webapps/#{server_file(node['myappfile'])}") }
end

The recipe copies the WAR file, Tomcat deploys it.

Deploy WAR from AWS S3 bucket to AWS linux instance

The final recipe example below copies (using AWS tools) the WAR file from an Amazon S3 bucket onto the linux instance running Tomcat, deployed by chef, in the Amazon Web Services cloud provider.

# Copy  WAR to webapps for auto-deployment - Requires that the instance have role with access to bucket
execute "aws s3 cp #{node['urls']['myappurl']} /var/lib/tomcat/webapps/" do
  action :run
  not_if { File.exist?("/var/lib/tomcat/webapps/#{server_file(node['urls']['myappurl'])}") }
end