Chapter 7. Continuous Delivery

This chapter will show the reader how to integrate their build pipeline and deployments with a Kubernetes cluster. It will cover the concept of using Gulp.js and Jenkins in conjunction with your Kubernetes cluster.

This chapter will discuss the following topics:

• Integrating with continuous deployment pipeline
• Using Gulp.js with Kubernetes
• Integrating Jenkins with Kubernetes

Integrating with continuous delivery pipeline

Continuous integration and delivery are key components to modern development shops. Speed to market or mean-time-to-revenue are crucial for any company that is creating their own software. We'll see how Kubernetes can help you.

CI/CD (short for Continuous Integration / Continuous Delivery) often requires ephemeral build and test servers to be available whenever changes are pushed to the code repository. Docker and Kubernetes are well suited for this task, as it's easy to create containers in a few seconds and just as easy to remove them after builds are run. In addition, if you already have a large portion of infrastructure available on your cluster, it can make sense to utilize the idle capacity for builds and testing.

In this article, we will explore two popular tools used in building and deploying software:

• Gulp.js: This is a simple task runner used to automate the build process using JavaScript and Node.js
• Jenkins: This is a fully-fledged continuous...

Gulp.js

Gulp.js gives us the framework to do Build as code. Similar to Infrastructure as code, this allows us to programmatically define our build process. We will walk through a short example to demonstrate how you can create a complete workflow from a Docker image build to the final Kubernetes service.

Prerequisites

For this section of the article, you will need a NodeJS environment installed and ready including the node package manager (npm). If you do not already have these packages installed, you can find instructions for installing them at https://docs.npmjs.com/getting-started/installing-node.

You can check whether NodeJS is installed correctly with a node -v command.

You'll also need Docker CE and a DockerHub account to push a new image. You can find instructions to install Docker CE at https://docs.docker.com/installation/.

You can easily create a DockerHub account at https://hub.docker.com/.

After you have your credentials, you can log in with the CLI using $ docker login command.

Gulp...

Kubernetes plugin for Jenkins

One way we can use Kubernetes for our CI/CD pipeline is to run our Jenkins build slaves in a containerized environment. Luckily, there is already a plugin, written by Carlos Sanchez, which allows you to run Jenkins slaves in Kubernetes' pods.

Prerequisites

You'll need a Jenkins server handy for this next example. If you don't have one you can use, there is a Docker image available at https://hub.docker.com/_/jenkins/.

Running it from the Docker CLI is as simple as this:

docker run --name myjenkins -p 8080:8080 -v /var/jenkins_home jenkins

Installing plugins

Log in to your Jenkins server, and from your home dashboard, click on Manage Jenkins. Then, select Manage Plugins from the list.

Note

A note for those installing a new Jenkins server: When you first log in to the Jenkins server, it asks you to install plugins. Choose the default ones or no plugins will be installed:

Jenkins main dashboard

The credentials plugin is required, but should be installed by default. We can...

Bonus fun

Fabric8 bills itself as an integration platform. It includes a variety of logging, monitoring, and continuous delivery tools. It also has a nice console, an API registry, and a 3D game that lets you shoot at your pods. It's a very cool project, and it actually runs on Kubernetes. Refer to http://fabric8.io/.

It's an easy single command to set up on your Kubernetes cluster, so refer to http://fabric8.io/guide/getStarted/gke.html.

Summary

We looked at two continuous integration tools that can be used with Kubernetes. We did a brief walk-through of deploying the Gulp.js task on our cluster. We also looked at a new plugin used to integrate Jenkins build slaves into your Kubernetes cluster. You should now have a better sense of how Kubernetes can integrate with your own CI/CD pipeline.