Isolated, Scalable, & Lightweight Environment for Training
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Isolated, Scalable, & Lightweight Environment for Training

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Making IT training a smoother process...

ISLET is a container based system for teaching Gnu/Linux based software, which requires minimal effort for participation and configuration. ISLET supports running a variety different training environments concurrently, and has a plugin system for extending functionality. ISET is modular in design, which makes it easy to add different run times and is flexible to different needs. The participation barrier is set very low, so students will only need an SSH or similar remote access client to connect.

ISLET Screenshot


  • Event and staff training
  • Capture the flag competitions
  • Development environments

Who Uses ISLET?

ISLET has been used in official training for two leading open source network security projects. These, in addition to other notable examples, are listed below.

If you would like commercial support for ISLET, including creating and deploying custom training environments, contact me through my company Draconyx.


These images are a little old, but they mostly represent the design.

Simplified Diagram

ISLET Diagram

Detailed Flowchart

ISLET Flowchart


The installation of ISLET is very simple. First, grab the dependencies and then install ISLET.


  • Linux, Bash, Cron, OpenSSH, Make, SQLite, and Docker Engine

The configure script will check for dependencies (except Docker)


ISLET Configure Screenshot

Typically, all you need is Make, SQLite and Docker Engine (for Debian/Ubuntu):

apt-get install make sqlite

See Docker's documentation for installation instructions.


After installing the dependencies, run:

make user-config && make install && make security-config

See the menu for more options, make ISLET Make Screenshot

Target: Description:
install Install ISLET: install-files + configuration
update Downloads and install new code (custom changes to default files will be overwritten)
uninstall Uninstall ISLET (Recommended to backup your stuff first)
mrproper Removes files that did not come with the source
user-config Configures a user account called demo w/ password demo
security-config Configures sshd with islet relevant security in mind
iptables-config Installs iptables ruleset

GNU make accepts arguments if you want a customized installation (not supported):

make user-config INSTALL_DIR=/usr/local/islet USER=training PASS=training
make install INSTALL_DIR=/usr/local/islet USER=training
make security-config INSTALL_DIR=/usr/local/islet USER=training
make uninstall INSTALL_DIR=/usr/local/islet USER=training
Variable: Description:
CONFIG_DIR ISLET configuration directory (def: /etc/islet)
INSTALL_DIR ISLET installation directory (def: /opt/islet)
USER User account created with user-config target (def: demo)
PASS User account password created with user-config target (def: demo)
IPTABLES Iptables ruleset (def: /etc/network/if-pre-up.d/iptables-rules)


Updating an existing ISLET installation is very simple:

tar zcf islet_config.tgz /etc/islet # Backup configs
make update
tar zxf islet_config.tgz -C /       # Restore configs

Adding Training Environments

See Docker's image documentation

  1. Build or pull in a new Docker image

  2. Create an ISLET config file for that image (training environment). You can use make template for an example.

  3. Place it in /etc/islet/environments with a .conf extension.

It should now be available from the selection menu upon login.

ISLET Configs Screenshot

More info: See the SECURITY file for more information on manually securing the system. See the ADMIN file for more information on administering the system. [Mailing List] (