Deploying The Applications

Objective: Create a Minecraft server app

One or more containers in an OKD cluster are configured in what is called a pod. Pods are distributed across cluster nodes which contain the resources and services required to run the containers.

We're going to be using a publicly available image from the Docker Hub to deploy our Minecraft server on OKD.

This guide will cover 2 ways to create new apps in OKD. The first is through the web console and the second is in the oc cli.

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Creating a project in the web console

Before doing anything you need to create a project for all of your apps to run in.

• Navigate to the web console.
• login as developer if prompted using any non-blank password
• One the home page click Create Project.
• Name the project minecraft-server
• You can also add a Display name and Description if you would like.

Now you're ready to create your app.

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Creating an app in the Web Console

Click the project you just created to enter it

• Now click the Add to Project Dropdown on the top right and then Deploy Image

• Now click the Image Name radio as we will be using an image from the docker hub
• Type itzg/minecraft-server and click the magnifying glass
• Change the name of the application to hub
• Now click Deploy

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Diagnosing the Application

Now you've created the application!

Looks like there is an error though...

• Click View Log to see what the error is.

chmod: /data: Operation not permitted
Please accept the Minecraft EULA at
 https://account.mojang.com/documents/minecraft_eula 
by adding the following immediately after 'docker run':
 -e EULA=TRUE

This error is because the Minecraft server application requires you to set the EULA environment variable to TRUE signifying that you accept the EULA.

• Navigate to Applications -> Deployments -> hub -> Environment
• Now add a EULA environment variable with a value of true
• Click Save

• Navigate to Applications -> Pods -> hub-X-XXXXX -> Logs
• Now you will see your application deploying

By changing the environment variable and clicking save you triggered a new deployment of the application.

You can also set the environment variables in the a similar way when you create the application.

See the itzg/minecraft-server docker hub page for more documentation on the available environment variables for this image.

Creating a another app in the Command Line

To access the command line for your cluster you must first add the oc binary to your $PATH so that you can use the oc command.

Luckily minishift provides and easy command for you to do this.

minishift oc-env

Use the command they provide to configure your shell.

• Now login to the cluster as developer using any non-blank password if prompted

  oc login -u developer

• Swtich to the minecraft-server project

  oc project minecraft-server

• Create and app called smp with the environment variable EULA set to true from the image itzg/minecraft-server

  oc new-app --name=smp -e EULA=true itzg/minecraft-server

Now type oc status to view the deployment

You can use oc get pods to see what pods are running in your project

Then use oc logs <pod name> to view a pod's logs

Changing Environment Variables in the CLI

Both of the applications we deployed are running using the stock minecraft-server.jar file. This is fine for now but later we want to proxy connections to these servers using bungeecord so we will need to use a different server binary.

By changing an environment variable in both of the applications we can run a PaperSpigot server instead that has support for bungeecord.

Add an environment variable called TYPE and set it's value to PAPER in both applications.

oc set env dc/smp TYPE=PAPER

oc set env dc/hub TYPE=PAPER

The dc is used to specify the resource type for each application that you are modifying. dc stands for Deployment Config which are the instructions for creating the application. We will cover deployment config more in step 2.

Now the applications will start a new deployment with those new environment variables.

What is Configured So Far

Now you should have two apps running. These are both minecraft servers and are configured to run on PaperSpigot.

Add One more application called bungee using either the Web UI or CLI.

• Do not specify any environment variables
• Use this image to create the app itzg/bungeecord

After this you should have 3 apps running in the minecraft-server project