vagrant-saltlab

Using HashiCorp Vagrant to run a portable, redeployable Salt lab environment on my Chromebook.

The included Vagrantfile spawns a environment with a single Salt Master (named salt) and four Salt Minions (named minion##) running different common Linux distributions for learning, testing, and development. It leverages the libvirt provider to interact with native Linux virtualization, and has a few tweaks to work around limitations imposed by running this all within ChromeOS's LXC-based Linux development environment.

To make it easier to deploy, test, break, tear down, and redeploy the environment:

• The Salt master blindly auto-accepts all minion keys.
• The minions register the roles:saltlab grain to aid in targeting.
• The master uses gitfs to pull the starter Salt content from this very Github repo.
• Additionally, the contents of salt_content/local get rsynced to /srv/ when the master starts up to make it easier to write/test Salt content locally. This is a one-way rsync from host to VM (and not the other way around), so make sure to write your Salt content on the host and use vagrant rsync to push changes into the VM.

Preparation

See the blog post for full details on how I've configured my environment.

Here's the crash course:

1. Verify support for nested virtualization:

ls -l /dev/kvm

2. Install prerequisites:

sudo apt update && sudo apt install \
  build-essential \
  gpg \
  lsb-release \
  rsync \
  wget

3. Install virt-manager and libvirt-dev:

sudo apt install virt-manager libvirt-dev

4. Configure libvirt:

sudo gpasswd -a $USER libvirt ; newgrp libvirt
echo "remember_owner = 0" | sudo tee -a /etc/libvirt/qemu.conf
echo "namespaces = []" | sudo tee -a /etc/libvirt/qemu.conf
sudo systemctl restart libvirtd

5. Install Vagrant

wget -O- https://apt.releases.hashicorp.com/gpg | gpg --dearmor | sudo tee /usr/share/keyrings/hashicorp-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/hashicorp-archive-keyring.gpg] https://apt.releases.hashicorp.com $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/hashicorp.list
sudo apt update
sudo apt install vagrant

6. Install vagrant-libvirt plugin:

vagrant plugin install vagrant-libvirt

Usage

Clone this repo:

git clone https://github.com/jbowdre/vagrant-saltlab.git
cd vagrant-saltlab

Review the Vagrantfile, and adjust CPU_COUNT and MEMORY_MB if needed. Note that some of the machines won't function correctly with less than 1024 MB.

vim Vagrantfile

Provision the virtual environment:

vagrant up

The master and four minions will be deployed; this will take several minutes. Once complete, you can verify status with vagrant status:

vagrant status
Current machine states:

salt           running (libvirt)  # master, ubuntu 22.04
minion01       running (libvirt)  # ubuntu 22.04
minion02       running (libvirt)  # ubuntu 20.04
minion03       running (libvirt)  # rocky 8
minion04       running (libvirt)  # rocky 9

This environment represents multiple VMs. The VMs are all listed
above with their current state. For more information about a specific
VM, run `vagrant status NAME`.

Access an SSH shell on the master with vagrant ssh salt:

vagrant ssh salt
Welcome to Ubuntu 22.04.3 LTS (GNU/Linux 5.15.0-83-generic x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/pro

  System information as of Tue Feb  6 04:28:02 PM UTC 2024

  System load:  0.072265625        Processes:             104
  Usage of /:   14.3% of 30.34GB   Users logged in:       0
  Memory usage: 59%                IPv4 address for eth0: 192.168.121.69
  Swap usage:   0%                 IPv4 address for eth1: 192.168.100.120


This system is built by the Bento project by Chef Software
More information can be found at https://github.com/chef/bento
Last login: Tue Feb  6 14:37:44 2024 from 192.168.121.1
vagrant@salt:~$

Verify that all the minion keys have been automatically accepted by the master (this is a lab environment, after all):

vagrant@salt:~$ sudo salt-key -L
Accepted Keys:
minion01
minion02
minion03
minion04
salt
Denied Keys:
Unaccepted Keys:
Rejected Keys:

Make sure all the minions are responding correctly:

vagrant@salt:~$ sudo salt '*' test.ping
salt:
    True
minion03:
    True
minion02:
    True
minion01:
    True
minion04:
    True

And confirm that the local and remote content has been successfully merged into the salt:// file system:

vagrant@salt:~$ sudo salt-run fileserver.file_list
- _reactor/sync_grains.sls    # gitfs
- neofetch/init.sls           # local
- neofetch/uninstall.sls      # local
- top.sls                     # gitfs
- users/init.sls              # gitfs
- vim/init.sls                # gitfs
- vim/uninstall.sls           # gitfs
- vim/vimrc                   # gitfs
- webserver/index.html        # gitfs
- webserver/init.sls          # gitfs
- webserver/uninstall.sls     # gitfs

You can then apply a state like so:

vagrant@salt:~$ sudo salt '*' state.apply neofetch

Happy Salting!

Cleanup

To blow it all away for a fresh start, just run vagrant destroy -f. You can then re-do vagrant up.