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One of the challenges or points of friction for me using Proxmox in my home lab has been integrating Ansible with it more cleanly. The issue is I have traditionally maintained my inventory file manually which is a bit of a hassle. Part of the issue is that Proxmox doesn’t really expose a lot of metadata about the VMs you have running to things like tagging don’t actually exist. Despite that I set out to get a basic, dynamically generated inventory system that will work against my Proxmox installation to make the process at least a bit smoother.

For some time, Ansible has supported the idea of dynamic inventory. This type of inventory will query a backend to build out an inventory that is compliant with Ansible. Proxmox, having an API, has a dynamic inventory plugin available from the community. In this post I will showcase how I got started with a basic Proxmox dynamic inventory.

When I set out I had a few requirements. First, I really don’t have a naming convention of my VMs that makes any sense in DNS. Some systems have a fully qualified domain but most do not. The ones that do have fully qualified domain name wouldn’t actually be available over ssh on the IP resolved for that domain. To get around this, I wanted to be able to map the host name in Proxmox to its internal IP address. By default, the dynamic inventory plugin will set ansible_host to the name of the VM. For this I had to provide a compose entry to set the ansible_host which you’ll see below. This feature is made possible because I always install the qemu guest agent.

The second requirement is that ssh connection info was dynamic as well because I use a number of different operating systems. Since all of my systems use cloud-init I am able to set the ssh username to the ciuser value thus ensuring I always know what the ssh user is regardless of the operating system used.

Here is my dynamic inventory file:

plugin: community.general.proxmox
validate_certs: false
want_facts: true
compose:
  ansible_host: proxmox_agent_interfaces[1]["ip-addresses"][0].split('/')[0]
  ansible_user: proxmox_ciuser

I placed this information into inventory/inventory.proxmox.yaml. Most of the entries are self-explanatory but I will go through what the compose section is doing.

The first item in the compose section is setting the ansible_host. When the inventory plugin gathers information from Proxmox it will gather the assigned IP addresses as determined using the Qemu Guest Agent. In all cases that I could see, the first IP address will be localhost and the second one will always be the primary interface in the system. With information known, I was able to create the jinja2 template to grab the correct IP address and strip the netmask off of it.

The next line is setting the ansible_user by just copying the proxmox_ciuser value. With these two variables set, Ansible will use that username when connecting to the host at its internal IP address. Since the systems were brought up using cloud-init, my ssh key is already present on all of the machines and the connection works without much fuss.

To support this configuration, here is my ansible.cfg:

[defaults]
inventory = ./inventory
fact_caching_connection = .cache
retry_files_enabled = False
host_key_checking = False
forks = 5
fact_caching = jsonfile

[inventory]
cache = True
cache_plugin = jsonfile

[ssh_connection]
pipelining = True
ssh_args = -F ssh_config

This configuration is setting a few options for me related to how to find the inventory, where to cache inventory information and where to cache facts about remote machines. Caching this info greatly speeds up your Ansible runs and I recommend it. The ssh_args value allows me to specify some additional ssh connection info.

In addition to the above configuration files, there are environment variables that are set on my system. These variables define where to find the Proxmox API, what user to connect with and the password. The environment variables are defined on the dynamic inventory plugin page but here is what my variables look like:

PROXMOX_PASSWORD=[redacted]
PROXMOX_URL=https://[redacted]:8006/
PROXMOX_INVALID_CERT=True
PROXMOX_USERNAME=root@pam
PROXMOX_USER=root@pam

The user/username value is duplicated because some other tools rely on PROXMOX_USERNAME instead of PROXMOX_USER.

And that’s it! With this configured I am able to target all of my running hosts by targeting “proxmox_all_running”. For example, ansible proxmox_all_running -m ping will ping all running machines across my Proxmox cluster.

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Once in awhile I like to read about what kind of software and utilities other people are using on their system to make their lives easier. It’s always interesting to see what mix of tools people are using and often times I learn about a new tool I hadn’t heard of before. Today I thought I’d do the same as I’ve started using a number of new tools on a regular basis just in the past six months.

As a systems engineer that is also familiar with programming I have what may be a unique mix of software and tools on my computer. Let’s take a look.

Operating System(s)

I have been using macOS full time since about 2008. I use macOS because it is a mix Unix and a GUI (NeXT if you’re keeping score) which gives me a familiar and robust command line environment with an excellent desktop environment.

I also use Linux heavily but almost never as a desktop or workstation. I have a laptop that I can dual boot between Linux and macOS for testing. I also run multiple Linux systems to run Proxmox for virtualization. Proxmox is a great way to get use out of otherwise retired computers. In fact, my Proxmox cluster is an older HP desktop with a quad core processor mixed with a pair of old MacBooks. I have written about Proxmox before and you can find it here.

I have one Windows PC that exists mostly because of games but also some business software.

Software Tools

When it comes to software these are the tools I use most frequently.

  • Code Editing and Runtimes/Languages
  • DevOps Type Stuff
  • Kuberenetes
    • kubectx/kubens for easy cluster and namespace switching
    • k9s for a text based UI to Kubernetes
  • Utilities
    • Brew
    • Patterns tool for working with regular expressions. Been using it for years but several tools now exist like it
    • iTerm 2 superior to the default terminal available in macOS
  • Other
    • Spotify for music
    • VirtualBox for testing Ansible roles
    • Twitter client
    • Mail.app
    • RamBox for chat
    • Bear for notes

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UPDATE: This method is old and outdated. Most of the time this is probably what you actually want – https://docs.ansible.com/ansible/latest/modules/reboot_module.html.

Sometimes when using Ansible there is the need to reboot a server and wait for it to return. This simple recipe will allow you to achieve that while also getting some nice feedback so you know what is going on. You can place these tasks into a role or just in your playbook:

- name: Store target host and user
  set_fact:
  target_host: "{{ ansible_host }}"
  target_user: "{{ ansible_user }}"
 
- name: Reboot the server
  shell: sleep 2 && shutdown -r now "Ansible package updates triggered"
  async: 1
  poll: 0
  ignore_errors: true
 
- name: Wait for server to shutdown
  local_action: shell ssh -o BatchMode=yes -o ConnectTimeout=2 -o StrictHostKeyChecking=no "{{ target_user }}@{{ target_host }}" true
  register: result
  until: result.rc != 0
  failed_when: result.rc == -1
  retries: 200
  delay: 1
 
- name: Wait for server to be ready
  local_action: shell ssh -o BatchMode=yes -o ConnectTimeout=2 -o StrictHostKeyChecking=no "{{ target_user }}@{{ target_host }}" true
  register: result
  until: result.rc == 0
  retries: 200
  delay: 3

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Wanted to quickly share some thoughts and links of software I’ve found recently and what I’ve been up to.

If you’re into home automation at all you have to check out Home Assistant. There is a bit of a learning curve initially but once you get an understanding of how to configure it you’ll find there is a lot of potential with it. I recently replaced my HomeBridge installation on my Raspberry Pi 3 with the prebuilt RPi3 image.

If you manage servers big or small take a look at Ansible. It isn’t new technology but it is something I’ve grown quite fond of recently. It’s easy to install on Linux, Mac and even Windows 10 if you have that oddly named Linux add-on. Even if you don’t use Ansible to manage servers you should use something.

If you enjoy Destiny or Destiny 2, checkout Guardian Theater. This is a project spearheaded by a friend of mine after collaborating with me on a Xbox GameDVR clip site (https://xboxrecord.us) and deciding it’d be way cooler if you could look up clips related to yours. Guardian Theater promises to show game clips recorded by other guardians while in the same activity as you. Lots of fun!