Automating Proxmox Container Management with Ansible

Managing a growing homelab or server fleet manually is inefficient. If you're running multiple LXC containers on Proxmox, it makes sense to automate basic setup and maintenance. In this post, I'll show how to create an Ansible workflow that dynamically discovers containers, builds an inventory, and runs tasks like apt update, setting a default shell, and more.

Step 1: Dynamic Inventory with Proxmox

Start by querying Proxmox for a list of running containers. You can use a small Python script or shell script to generate a dynamic Ansible inventory.

Here's a quick and dirty example using pct:

#!/bin/bash
# save as generate_inventory.sh

echo "[lxc]"
for id in $(pct list | awk 'NR>1 {print $1}'); do
  ip=$(pct exec $id -- hostname -I | awk '{print $1}')
  name=$(pct exec $id -- hostname)
  echo "$name ansible_host=$ip ansible_user=root"
done

Make it executable:

chmod +x generate_inventory.sh

Run it like this to feed directly into Ansible:

ansible -i <(./generate_inventory.sh) lxc -m ping

Or you can redirect the output to a static file:

./generate_inventory.sh > inventory.ini

Step 2: Ansible Playbook for Container Setup

Now let's create a playbook that performs common setup steps.

# lxc_setup.yml
- name: Configure LXC containers
  hosts: lxc
  become: yes
  tasks:
    - name: Update apt cache and upgrade packages
      apt:
        update_cache: yes
        upgrade: dist

    - name: Install common packages
      apt:
        name:
          - curl
          - vim
          - sudo
        state: present

    - name: Change default shell to bash
      user:
        name: "{{ ansible_user }}"
        shell: /bin/bash

    - name: Ensure .bashrc is present
      copy:
        src: ./dotfiles/bashrc
        dest: /root/.bashrc
        owner: root
        group: root
        mode: '0644'

📝 Tip: You can create a dotfiles/bashrc file with your custom shell config.

Step 3: Run It All

Once your inventory is ready and your playbook is defined, run it:

ansible-playbook -i inventory.ini lxc_setup.yml

Or directly with the dynamic inventory script:

ansible-playbook -i <(./generate_inventory.sh) lxc_setup.yml

Conclusion

This setup saves a ton of time when managing multiple containers in a homelab or test environment. You can extend the playbook to configure SSH keys, install Docker, or set up monitoring agents—whatever you need. The key is building automation into your workflow early so you can scale without stress.

Let me know if you'd like a downloadable repo or if I should turn this into a role-based structure next!