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Last pushed: 2 years ago
Short Description
Prepare VMs for Docker workshops.
Full Description

Trainer tools to prepare VMs for Docker workshops

There are several options for using these tools:

Clone the repo

$ git clone
$ cd prepare-vms
$ docker-compose build
$ mkdir $HOME/bin && ln -s `pwd`/trainer $HOME/bin/trainer

Via the image

$ docker pull soulshake/prepare-vms


This repo can be added as a submodule in the repo of the Docker workshop:

$ git submodule add


Export needed envvars

Required environment variables:


Update settings.yaml

If you have more than one workshop:

$ cp settings.yaml settings/YOUR_WORKSHOP_NAME-settings.yaml
$ ln -s settings/YOUR_WORKSHOP_NAME-settings.yaml `pwd`/settings.yaml

Update the settings.yaml as needed. This is the file that will be used to generate cards.



Summary of steps to launch a batch of instances for a workshop:

  • Export the environment variables needed by the AWS CLI (see Requirements below)
  • trainer start NUMBER_OF_VMS to create AWS instances
  • trainer deploy TAG to run scripts/postprep.rc via parallel-ssh
  • trainer pull-images TAG to pre-pull a bunch of Docker images
  • trainer test TAG
  • trainer cards TAG to generate a PDF and an HTML file you can print

The trainer script can be executed directly.

It will check for the necessary environment variables. Then, if all its dependencies are installed
locally, it will execute trainer-cli. If not, it will look for a local Docker image
tagged soulshake/trainer-tools. If found, it will run in a container. If not found,
the user will be prompted to either install the missing dependencies or download
the Docker image.

Detailed usage

Start some VMs

$ trainer start 10

A few things will happen:

Sync of SSH keys

When the start command is run, your local RSA SSH public key will be added to your AWS EC2 keychain.

To see which local key will be uploaded, run ssh-add -l | grep RSA.

Instance + tag creation

10 VMs will be started, with an automatically generated tag (timestamp + your username).

Your SSH key will be added to the authorized_keys of the ubuntu user.

Creation of ./$TAG/ directory and contents

Following the creation of the VMs, a text file will be created containing a list of their IPs.

This ips.txt file will be created in the $TAG/ directory and a symlink will be placed in the working directory of the script.

If you create new VMs, the symlinked file will be overwritten.


Instances can be deployed manually using the deploy command:

$ trainer deploy TAG

The postprep.rc file will be copied via parallel-ssh to all of the VMs and executed.

Pre-pull images

$ trainer pull-images TAG

Generate cards

$ trainer cards TAG

List tags

$ trainer list

List VMs

$ trainer list TAG

This will print a human-friendly list containing some information about each instance.

Stop and destroy VMs

$ trainer stop TAG


  • Don't write to bash history in system() in postprep
  • compose, etc version inconsistent (int vs str)
Docker Pull Command
Source Repository