ctlabs.rb

Overview

With ctlabs.rb we can create Lab-Environments similar to docker-compose, but especially designed to create complex network setups and easy to access containers that feel like Virtual Machines. Additionally the network is separated into a management part and a data part so that we can use the management network to further run ansible (or saltstack, pupet, ...) to manage the nodes.

We can also use terraform to create cloud vms in gcp/aws. The terraform code creates a VM with all necessary dependencies to run ctlabs.rb. It is available here: ctlabs-terraform.

container that feel like VMs
Management Network
Data Network
configuration automation

Cloud VM's

Terraform Code

We use the script ctlabs.rb to bring up a lab environment that we defined in a lab configuration yaml file. The configuration file format is explained in lab configuration .

Existing Lab Configurations:

github.com/oxdeca

Lab Configuration explained:

lab configuration

Ansible Playbooks

Starting a lab

E.g. the following output shows how we bring up the lpic210 lab environment. Each line beginning with the word running shows a node being started and each line beginning with the work connect() shows a link being brought up.

Running Ansible Playbook

We can add a playbook that should be run once the environment was spun up. The command is set as part of the controller node in the lab configuration. E.g. lpic210.yml

...

ansible :

type : controller

gw : 192.168.40.1

nics :

eth0: 192.168.40.3/24

vols : ['/root/ctlabs-ansible/:/root/ctlabs-ansible/:Z,rw']

play : ansible-playbook -i ./inventories/lpic210.ini ./playbooks/lpic2.yml --skip-tags sssd

Listing Container

Once we brought up the environment we can use the podman/docker commands. E.g. with docker ps we can list the running container.

Stopping a lab

To bring down a lab environment we use the -d flag. We also need to provide the same configuration file we used to bring up the environment.

Entering a container

If we use a cloud vm (as described in cloud vms) we can use the command enter <container> to enter a container.

Visualisation

We can also get a visual overview of the lab by using the server.rb script. We can start is manually or use systemd to auto-start it. A service file is included in the ctlabs repository . By default it is listening on port 4567. If we used the terraform configuration as described here we can connect to the WebInterface via the public ip of the vm.

We can find the public ip of our gcp-vm in the console under virtual machines -> VM instances. (see below)

Overview (Connections and Topology)

The overview is devided into the sections

Connections
Topology

The Connections section show us how the interfaces are connected with each other.

The Topology section shows us how the nodes are logically connected

Topology

The Topology view is divided into the sections

Data Network

Management Network

The Management Network is used to manage the nodes and the Data Network is the Core Network, i.e. the network used for the services.

Connection Details

The Connections view is also divided into the sections

Data Network
Management Network

YAML Configuration and Inventory

We can inspect the yaml configuration in the Configuration View and generated ansible inventory of the last used lab in the Inventory View.

The ansible inventory is used by the ansible plays:

https://github.com/oxdeca/ctlabs-ansible

Google Sites

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