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Getting Started

We will be developing and deploying a Node.JS application to an OpenShift cluster in this guide.

We'll be going over the following steps:

Your first application

  1. Running OpenShift
  2. Create an application
  3. Create a component
  4. Accessing the component
  5. Pushing new changes to the component
  6. Adding storage to the component

Extra documentation

Your first application

1. Running OpenShift

A few requirements before we proceed!

The quickest way to deploy a development OpenShift cluster is by using minishift. Alternatively, odo will automatically work with any OpenShift cluster you're currently logged into.

Running Minishift

If you lack a local development cluster, Minishift provides the easiest way of getting started:

$ minishift start       
-- Starting profile 'minishift'
-- Checking if https://github.com is reachable ... OK
-- Checking if requested OpenShift version 'v3.9.0' is valid ... OK
-- Checking if requested OpenShift version 'v3.9.0' is supported ... OK
-- Checking if requested hypervisor 'kvm' is supported on this platform ... OK
-- Checking if KVM driver is installed ...
   Driver is available at /usr/local/bin/docker-machine-driver-kvm ...
   Checking driver binary is executable ... OK
-- Checking if Libvirt is installed ... OK
-- Checking if Libvirt default network is present ... OK
-- Checking if Libvirt default network is active ... OK
-- Checking the ISO URL ... OK
-- Checking if provided oc flags are supported ... OK
-- Starting local OpenShift cluster using 'kvm' hypervisor ...
-- Starting Minishift VM .................. OK
-- Checking for IP address ... OK
-- Checking for nameservers ... OK
-- Checking if external host is reachable from the Minishift VM ...
   Pinging 8.8.8.8 ... OK
-- Checking HTTP connectivity from the VM ...
   Retrieving http://minishift.io/index.html ... FAIL
   VM cannot connect to external URL with HTTP
-- Checking if persistent storage volume is mounted ... OK
-- Checking available disk space ... 11% used OK
-- OpenShift cluster will be configured with ...
   Version: v3.9.0
-- Copying oc binary from the OpenShift container image to VM .... OK
-- Starting OpenShift cluster .................
Deleted existing OpenShift container
Using Docker shared volumes for OpenShift volumes
Using public hostname IP 192.168.42.10 as the host IP
Using 192.168.42.10 as the server IP
Starting OpenShift using openshift/origin:v3.9.0 ...
OpenShift server started.

The server is accessible via web console at:
    https://192.168.42.10:8443

Now log into the OpenShift cluster:

$ odo login -u developer -p developer
Login successful.

You have one project on this server: "myproject"

Using project "myproject".

Now we can move on to creating our application using odo.

2. Create an application

An application is an umbrella that will comprise all the components (microservices) you will build.

Let's create an application:

$ odo app create nodeapp
 Creating application: nodeapp in project: myproject
Switched to application: nodeapp in project: myproject

3. Create a component

First, we'll download the our test application:

$ git clone https://github.com/openshift/nodejs-ex
Cloning into 'nodejs-ex'...
remote: Counting objects: 568, done.
remote: Total 568 (delta 0), reused 0 (delta 0), pack-reused 568
Receiving objects: 100% (568/568), 174.63 KiB | 1.53 MiB/s, done.
Resolving deltas: 100% (224/224), done.

$ cd nodejs-ex 
~/nodejs-ex  master

Now that you've created an application, add a component of type nodejs to the application, from the current directory where our code lies:

$ odo create nodejs
 ✓   Checking component
 ✓   Checking component version
 ✓   Creating component nodejs-ex-nodejs-nnjf
 ✓   Component 'nodejs-ex-nodejs-nnjf' was created and port 8080/TCP was opened
 ✓   Component 'nodejs-ex-nodejs-nnjf' is now set as active component
To push source code to the component run 'odo push'

Note: You can explicitly supply an image version by using: odo create openshift/nodejs:8. Otherwise, the latest image is used.

Now that a component is running we'll go ahead and push our initial source code!

$ odo push
Pushing changes to component: nodejs-ex-nodejs-nnjf
 ✓   Waiting for pod to start
 ✓   Copying files to pod
 ✓   Building component
 ✓   Changes successfully pushed to component: nodejs-ex-nodejs-nnjf

Great news! Your component has been deployed to OpenShift! Now we'll connect to the component.

4. Accessing the component

To access the component, we'll need to create an OpenShift route:

$ odo url create
Adding URL to component: nodejs-ex-nodejs-nnjf
 ✓   URL created for component: nodejs-ex-nodejs-nnjf

nodejs-ex-nodejs-nnjf - http://nodejs-ex-nodejs-nnjf-nodeapp-myproject.192.168.42.90.nip.io

Now simply access the URL nodejs-ex-nodejs-nnjf-nodeapp-myproject.192.168.42.90.nip.io in the browser and you will be able to view your deployed application.

5. Pushing new changes to the component

Let's make some changes to the code and push them.

Edit one of the layout files within the Node.JS directory.

$ vim views/index.html

Now let's push the changes:

$ odo push
Pushing changes to component: nodejs-ex-nodejs-nnjf
 ✓   Waiting for pod to start
 ✓   Copying files to pod
 ✓   Building component
 ✓   Changes successfully pushed to component: nodejs-ex-nodejs-nnjf

Refresh your application in the browser, and you'll be able to see the changes.

After each change, you can continue updating your component by using: odo push nodejs.

6. Adding storage to the component

Now that you've got your component running, how do you persist data between restarts?

If you wish to add storage to your component, odo makes it very easy for you to do this:

$ odo storage create nodestorage --path=/opt/app-root/src/storage/ --size=1Gi 
 ✓   Added storage nodestorage to nodejs-ex-nodejs-nnjf

That's it! Storage has been added your component with an allocated size of 1 Gb.

Command completion

Command completion is currently only supported for bash, zsh and fish shells.

odo provides smart completion of command parameters based on user input. For this to work, odo needs to integrate with the executing shell.

This can be installed automatically, running:

odo --complete

and pressing y when asked to install the completion hook.

You can also install the completion hook manually by adding:

complete -o nospace -C <full path to your odo binary> odo

to your shell configuration file (e.g. .bashrc for bash).

To disable completion, run:

odo --uncomplete

After any modification to your shell configuration file, you will need to source it or restart your shell.

NOTE: The completion system will stop working if you either rename the odo executable or move it. You will therefore need to re-enable it accordingly.

OpenShift notes

These are some extra installation / getting started instructions for your local OpenShift cluster.

Service Catalog

In order to use the Service Catalog it must be enabled within your OpenShift cluster.

Requirements:

  • minishift version 1.22+

If you are using minishift you'll need to start an OpenShift cluster with version 3.10.0+ and Service Catalog explicitly enabled.

# Deploy minishift
MINISHIFT_ENABLE_EXPERIMENTAL=y minishift start --extra-clusterup-flags "--enable=*,service-catalog,automation-service-broker"

After you've enabled / started minishift, you'll be able to list the services via odo catalog list services and service catalog related operations via odo service <verb> <servicename>.

Adding a Custom Builder

This section assumes that the oc binary has been installed and is present on the $PATH

OpenShift includes the ability to add a custom image to bridge the gap in the creation of custom images.

A custom builder image usually includes the base image of openshift/origin-custom-docker-builder.

Below is an example of how to successfully import and use the redhat-openjdk-18 image:

# Import the image into OpenShift
oc import-image openjdk18 --from=registry.access.redhat.com/redhat-openjdk-18/openjdk18-openshift --confirm

# Tag the image so it is accessible by Odo
oc annotate istag/openjdk18:latest tags=builder

After tagging the image, you may now deploy it with Odo:

odo create openjdk18 --git https://github.com/openshift-evangelists/Wild-West-Backend