Docker in your virtual machine

This is a 1-day course.

Instructor: Jacob Boschee (UBC)

Target audience: general

Level: beginner

Prerequisites: Introduction to Compute Canada cloud course

We will be running Docker inside virtual machines (VMs) in Compute Canada cloud, so you must be familiar with setting up a blank Ubuntu server in a cloud VM before attending this course.

Software: All attendees will need a remote secure shell (SSH) client installed on their computer in order to participate in the course exercises. On Windows we recommend the free Home Edition of MobaXterm. On Mac and Linux computers SSH is usually pre-installed (try typing ssh in a terminal to make sure it is there).

June-30

Zoom

9am-noon Pacific Live session: 30-40 min presentation blocks.

Materials to download:

PDF slides
raw text document with all commands
Gnuplot example script

Exercises

Exercise 1: Hello Docker!

In this exercise we will install docker on our VM and run the test Hello World docker. Before continuing with this exercise please be sure you have an Ubuntu (or CentOS) VM set up that you are able to log into. For details on setting up a VM with your guest account, check these PDF slides from yesterday’s CC Cloud course or the videos therein.

Once you are logged into your VM, and you are using Ubuntu, please follow along with the video and execute the following commands (one command at a time!):

sudo apt-get update
sudo apt-get install apt-transport-https ca-certificates curl gnupg-agent software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io
sudo docker run hello-world

If you are working with a CentOS VM (following yesterday’s cloud course), then the commands for this exercise are:

sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
sudo yum install wget docker-ce docker-ce-cli containerd.io 
sudo systemctl start docker
sudo docker run hello-world

Exercise 2: Setting up a CentOS Docker Container

In this exercise we will use Docker to download and run a copy of CentOS on our Ubuntu VM. To follow along with the exercise video, please use the following list of commands (one command at a time!):

sudo docker images
sudo docker search centos
sudo docker pull centos
sudo docker run -it --name First_Centos centos
cat /etc/redhat-release

Exercise 3: Working within a Docker Container and Host Connections

In this exercise we will be using Docker to create a container for running gnuplot. To pass the output files from gnuplot back to our host system we will set up a mount volume attached to a folder in the host. To follow along with the exercise video please use the following list of commands (one command at a time!):

mkdir ~/input
sudo docker run -it --name gnuPlotExample -v ~/input:/workdir centos
yum install gnuplot
cd /workdir
wget https://wgschool.netlify.app/docker/pm3d_lighting.2.gnu
gnuplot /workdir/pm3d_lighting.2.gnu
exit

Once complete with the commands, use MobaXTerm’s file browser to locate pm3d_lighting.2.png within the inputs folder to view the output of gnuplot.

Exercise 4: Building Docker Images for Portability

In this exercise we will use a Dockerfile to create a CentOS image with gnuplot already installed and ready to execute on a mounted volume. We will then repeat the results of Exercise 3 with this new image without using an interactive shell. Finally we will save and reimport a copy of the image we created to demonstrate the ability to port Docker images to other systems. To follow along with the exercise video, please use the following command:

nano Dockerfile

and then type the following into the file Dockerfile:

#CentOS GNUPlot
FROM centos
VOLUME /workdir
WORKDIR /workdir
RUN yum install gnuplot -y
ENTRYPOINT ["gnuplot"]

and save it, and then again in the shell (one command at a time!):

sudo docker build -t gnuplot_centos .
rm ~/input/pm3d_lighting.2.png
sudo docker run --name DockerGNUPlot -v ~/input:/workdir gnuplot_centos pm3d_lighting.2.gnu
ls ~/input
sudo docker image save -o gnuplotCentosDemo.tar gnuplotcentos
sudo docker image import gnuplotCentosDemo.tar importedgnuplot
sudo docker image list