Installing OpenShift on Ubuntu — 2021

Dockerized MERN on OpenShift — Part 1

In my spare time I’ve been wising up on React. As part of my learnings I decided to port my Rails website to a MERN stack. I find it useful to share my knowledge in order to further my understanding, so this is part one in my guide to create a dockerized MERN application that can be deployed to OpenShift.

Setting up Docker repository

The first thing to do is to set up Docker on your Ubuntu instance.

1. First, import the Docker GPG key

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

2. Setup the stable Docker repository

echo \
  "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Note: lsb_release -cs will return the name of your Ubuntu distribution. In my case it’s focal.

3. Update your apt package index and install Docker Engine and containerd

sudo apt-get install docker-ce docker-ce-cli containerd.io

Note: Containerd is a container lifecycle manager

4. Verify that all of the above has completed successfully by running

sudo docker run hello-world

This should output the following (or something similar):

Terminal output after running `docker run hello-world`

5. Add your user to the docker group

sudo usermod -aG docker $USER

Setting up OpenShift

Now that Docker is installed we need to install OpenShift.

1. First, download and extract the latest OpenShift Origin

wget https://github.com/openshift/origin/releases/download/v3.11.0/openshift-origin-client-tools-v3.11.0-0cbc58b-linux-64bit.tar.gz
tar xvzf openshift*.tar.gz

2. Move kubectl and oc binaries

cd openshift-origin-client-tools*/
sudo mv oc kubectl /usr/local/bin/

4. Verify that OpenShift has installed correctly

oc version

This should output detail on the OpenShift install

> oc v3.11.0+0cbc58b
kubernetes v1.11.0+d4cacc0
features: Basic-Auth GSSAPI Kerberos SPNEGO

5. Insecure the registry and restart Docker

cat << EOF | sudo tee /etc/docker/daemon.json
{
  "insecure-registries" : ["172.30.0.0/16"]
}
EOF
sudo systemctl restart docker

6. Bringing OpenShift up and down

sudo oc cluster up --public-hostname=<server_ip>
sudo oc cluster down 

7. Configure hosting server IP address

a. Edit the kubeconfig file

sudo nano ./openshift.local.clusterup/openshift-controller-manager/openshift-master.kubeconfig

b. Replace the default server address with the host address

server: https://<server_ip>:8443

Note: <server_ip> should be the IP address of your Ubuntu instance

9. After saving the file start the cluster

sudo oc cluster up --public-hostname=<server_ip>

10. Verify you can access the cluster by heading to the web console https://<server_ip>:8443/console

You should be able to see the following page to verify success:

If loading the console redirects you to 127.0.0.1 or you run into issues logging in as admin you might have started it without the public-hostname flag. In this case, bring the cluster down, remove the stored configuration and re-run:

sudo oc cluster down
rm -rf openshift.local.clusterup/
sudo oc cluster up --public-hostname=<server_ip>

Using OpenShift

Now that both Docker and OpenShift are installed lets go over the basics.

1. Log in through the CLI

sudo oc login -u USERNAME -p PASSWORD

Note: Set USERNAME to something memorable, as well as PASSWORD

Alternatively to logon as an administrator

sudo oc login -u system:admin

Note: Logging in as a system administrator will give you access to the built in projects, the password is:

2. It’s easy to switch between the different projects

sudo oc project <project_name>

Note: <project_name> should be the name of the project you wish to switch to

3. Logging in as your own user create your first project

sudo new-project dev --display-name="<project_name>" --description="<project_description>"

4. This project can be verified by checking the web console and logging in as the dev user you used to create the project.