Our training environment

Introduction

SSH terminal
Figure 37 : SSH terminal

Our training environment

  • If you are attending a tutorial or workshop:

    • a VM has been provisioned for each student

  • If you are doing or re-doing this course on your own, you can:

    • install Docker locally (as explained in the chapter "Installing Docker")

    • install Docker on e.g. a cloud VM

    • use https://labs.play-with-docker.com to instantly get a training environment

Our Docker VM

This section assumes that you are following this course as part of a tutorial, training or workshop, where each student is given an individual Docker VM.

  • The VM is created just before the training.

  • It will stay up during the whole training.

  • It will be destroyed shortly after the training.

  • It comes pre-loaded with Docker and some other useful tools.

What is Docker?

  • "Installing Docker" really means "Installing the Docker Engine and CLI".

  • The Docker Engine is a daemon (a service running in the background).

  • This daemon manages containers, the same way that an hypervisor manages VMs.

  • We interact with the Docker Engine by using the Docker CLI.

  • The Docker CLI and the Docker Engine communicate through an API.

  • There are many other programs, and many client libraries, to use that API.

Why don't we run Docker locally?

  • We are going to download container images and distribution packages.

  • This could put a bit of stress on the local WiFi and slow us down.

  • Instead, we use a remote VM that has a good connectivity

  • In some rare cases, installing Docker locally is challenging:

    • no administrator/root access (computer managed by strict corp IT)

    • 32-bit CPU or OS

    • old OS version (e.g. CentOS 6, OSX pre-Yosemite, Windows 7)

  • It's better to spend time learning containers than fiddling with the installer!

Connecting to your Virtual Machine

You need an SSH client.

  • On OS X, Linux, and other UNIX systems, just use ssh:
$ ssh <login>@<ip-address>

Checking your Virtual Machine

Once logged in, make sure that you can run a basic Docker command:

$ docker version
Client:
 Version:       18.03.0-ce
 API version:   1.37
 Go version:    go1.9.4
 Git commit:    0520e24
 Built:         Wed Mar 21 23:10:06 2018
 OS/Arch:       linux/amd64
 Experimental:  false
 Orchestrator:  swarm

Server:
 Engine:
  Version:      18.03.0-ce
  API version:  1.37 (minimum version 1.12)
  Go version:   go1.9.4
  Git commit:   0520e24
  Built:        Wed Mar 21 23:08:35 2018
  OS/Arch:      linux/amd64
  Experimental: false

If this doesn't work, raise your hand so that an instructor can assist you!