From Zero to Continuous Delivery

Software DevelopmentExtreme Programming
Written By Justin Beall

Imagine a world where a code update to fix a defect or add a feature is automatically pushed to production on commit (or merged pull request) to master! We live in a time where this is now a reality for many companies of all sizes. A few large company examples are: Google, Facebook, LinkedIn, Netflix, and Etsy.

The idea of working in a continuous delivery environment has been a dream of mine. It takes a particularly high level of cultural discipline, craftsmanship, and respect to implement within an organization. Essentially all the characteristics needed to be a world-class organization.

The technology and software to do so is the easy part, which will be the primary focus of this tutorial. As a result, I took the time to take a stab at creating a cloud-based solution for a simple Java web application.

This blog post contains a high-level overview of the concept that is continuous delivery. Then, a step-by-step walkthrough of getting a cloud-based solution working using GitHub, Snap-Ci, and OpenShift. When a new piece of code gets pushed to the repository master branch, tests will run, and if they pass, the code will automatically be deployed to the OpenShift server gear.

Here is my simple application URL:

Summary of Continuous Delivery

In his post on Continuous Delivery, Martin Fowler states Continuous Delivery is:

A software development discipline where you build software in such a way that the software can be released to production at any time.

In addition, Thought Works has a great blog post Architecting for Continuous Delivery where the author, Vishal Naik, states:

The goal of CD is to be able to release software frequently, and reliably, in a frictionless manner.

Create A Java Web App Using Maven

Create The Java Web Application

Install GitHub and create a new repository

Download and install Java 8 JDK

Set JAVA_HOME:

Download and install Tomcat 7

  • Tomcat 7x Download
  • Unzip Tomcat 7 into your directory of choice:
    • Referenced here on out as $TOMCAT
    • E.g.: C:\TOOLS\SERVER\apache-tomcat-7.0.67

Download Maven

Use maven to create the web-app archtype

From the command line:

~ mvn archetype:generate -DgroupId=com.$YOUR_NAME.hello_world \
   -DartifactId=mvn-hello-world -DarchetypeArtifactId=maven-archetype-webapp \
   -DinteractiveMode=false
~ xcopy mvn-hello-world/* $REPOSITORY
~ cd $REPOSITORY
~ mvn eclipse:eclipse -Dwtpversion="2.0"

Open the project with Eclipse

  • Download Eclipse
  • Create/load a workspace of your choice
    • Workspace referenced as $WORKSPACE
    • E.g.: C:\WORKSPACE\Personal\mvn-hello-world

Add Tomcat 7 server to workspace

  • Right click in Server tab, New -> Server
  • Apache -> Tomcat v7.0 Server -> Click Next
  • Browser to $TOMCAT and Click Finish

Import the web-app into the Eclipse workspace

  • File -> Import -> Existing Projects in Workspace
  • Select root directory as $PROJECT
  • Click Finish

Update pom.xml for Java 8 and javax.servlet dependency

Add the following dependency node:

<dependency>
  <groupId>javax.servlet</groupId>
  <artifactId>servlet-api</artifactId>
  <version>2.5</version>
</dependency>

Validate no compile or build errors exist within the Markers tab

Add project to Tomcat

  • Right click on the Tomcat server, click Add and Remove...
  • Click Add All >>, then click Finish

Run the Tomcat server

Commit and push code to GitHub

From the command line:

~ cd $PROJECT
~ git add *
~ git commit -m "Initial project creation"

Create The OpenShift Server

Please reference my blog post on OpenShift for step by step on how to do this

For the purposes of this tutorial, we need a Java server of your choice. If you are not sure which one you need, select Tomcat 7.

Create SSH Keys On Windows

Use PuttyGen to create a Windows SSH key

  • PuTTY Download
  • Run PuTTYgen
  • Click the 'Generate' button and create a .ppk file
  • Click the 'Save public key' button
    • File Name id_rsa.pub
    • Directory (for all items) ~/.ssh
    • E.g.: C:\Users\Justin\.ssh
  • Click the 'Save private key' button
    • File name id_rsa.ppk
  • From the Conversions top menu select 'Export OpenSSH key'
    • File name id_rsa

Create Snap-CI Build

Browse to Snap-CI

Follow the login process and create a free account linked to your GitHub account

Commands to be executed in this stage

My commands are as follows:

mvn test package
git clone ssh://54fa354f4382ec1767000019@application-dev3l.rhcloud.com/~/git/application.git/
cp ./target/mvn-hello-world.war ./application/webapps
cd ./application
git add *
git commit -m "Install latest mvn-hello-world version"
git push

You will have to substitute your own OpenShift clone ssh URL.
The blog posts on OpenShift show where this can be found.

Secure Files

  • Click the 'Add new' link
  • Select your ~/.ssh/id_rsa file
  • Set the path to be a custom location of ~/.ssh/id_rsa

Update The GitHub Repository

Navigate to your GitHub repository (or do it through the command line / IDE), update any file, and watch the magic happen. It takes about a minute, but after that your new code is up and live for production use!

I like to update the index.jsp file, as this is an easy change to validate that deployment occurred.

Summary

This is a simple example that can be expanded upon by any skilled DevOps engineer.

In its most ideal form, continuous delivery integrates with production in real-time. But, if

there are business constraints that prevent production deployments, there is no reason why a test/staging environment could not be your company's continuous delivery target.

Feel free to contact me with any suggestions or questions!

Get In Touch

We'd love to hear from you! Whether you have a question about our services, need a consultation, or just want to connect, our team is here to help. Reach out to us through the form, or contact us directly via social media.

Justin Beall
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Utilizing OpenShift To Deploy a Web Application