About

This is an example debian linux router provisioned by ansible in a vagrant environment.

Vagrant VMs need to have a management network wich is NATted by the host, but that makes it difficult to play with the linux router, so this essentially adds a secondary network interface that is used for routing, and replaces the default route that is set by DHCP in eth0 to use our router in eth1 instead. So everything that would be normally done at eth0 must be done in eth1.

The network is setup as:

NB The dotted lines represent a network connection that is not directly used, instead, the traffic in those nodes goes through eth1 and is routed by the router machine.

NB For a non-ansible equivalent of this environment see rgl/debian-router-vagrant.

Usage

Install the base debian 11 box.

Install ansible in a python venv:

# NB this will use sudo to install system dependencies.
bash ansible-install.sh

Start this environment:

source ansible-env.sh
time vagrant up --provider=libvirt --no-destroy-on-error --no-tty

You can later trigger the ansible playbook execution with vagrant:

vagrant up --provision

You can also directly trigger the ansible playbook execution with ansible-playbook:

ansible-inventory --list --yaml
ansible-playbook playbook.yml --check --diff #-vvv
ansible-playbook playbook.yml --diff #-vvv

Network Packet Capture

You can easily capture and see traffic from the host with the wireshark.sh script, e.g., to capture the traffic from the eth1 interface on each VM:

./wireshark.sh router eth1 # or any
./wireshark.sh node1 eth1 # or any
./wireshark.sh node2 eth1 # or any

Reference

• https://www.vagrantup.com/docs/provisioning/ansible_intro
• https://www.vagrantup.com/docs/provisioning/ansible_common
• https://www.vagrantup.com/docs/provisioning/ansible
• https://docs.ansible.com/ansible-core/2.12/user_guide/playbooks.html
• https://docs.ansible.com/ansible-core/2.12/user_guide/playbooks_best_practices.html
• https://docs.ansible.com/ansible-core/2.12/reference_appendices/YAMLSyntax.html