Setting Up MAAS (Metal-as-a-Service) with UDM Pro on Ubuntu 22.04

Managing bare-metal servers with the same ease as cloud instances is a dream for many DevOps and infrastructure teams. That’s where MAAS (Metal-as-a-Service) comes in. By combining MAAS with a UDM Pro, you can automate Ubuntu deployments using PXE boot, VLANs, and DHCP—bringing cloud-like provisioning to your on-prem servers.

In this guide, I’ll walk through how to set up MAAS with UDM Pro to fully automate bare-metal server provisioning.

🔹 Why MAAS with UDM Pro?

• MAAS: Automates commissioning and deploying servers over PXE.
• UDM Pro: Handles DHCP, VLANs, and firewall rules, making PXE provisioning possible in a home lab or enterprise environment.

Together, they create a powerful, cloud-like provisioning system for physical infrastructure.

⚙️ Prerequisites

1. UDM Pro Configuration
   • Enable Option 66 & Option 67 for network boot.
   • Use the absolute path for the boot file, e.g.:

     bootloader/uefi/amd64/grubx64.efi
     

   • Add a firewall rule for PXE/TFTP traffic:

     Rule details:

     • Name: Maas server
     • Type: LAN IN
     • Action: Accept
     • Protocol: UDP
     • Ports: 69–65535
     • Destination: MAAS server IP

1. Install MAAS

sudo add-apt-repository ppa:maas/3.4 -y
sudo apt update
sudo apt install maas maas-cli maas-dhcp maas-dns -y
sudo maas init

2. Add Admin User & API Key Setup

After installation, you need to create the first admin user.

sudo maas createadmin

This will ask for:

• Username (e.g., admin)
• Email address
• Password

Once done, MAAS will be accessible at:

👉 http://<your-maas-server-ip>:5240/MAAS

Generate an API Key from the UI

1. Log in with the admin user credentials.
2. Go to your User Preferences (top-right corner).
3. Click Generate API Key.
4. Copy the key.

Login via CLI with API Key

maas login admin http://<your-maas-server-ip>:5240/MAAS <API_KEY>

3. Import Your SSH Key

To allow passwordless SSH login to deployed machines, import your public SSH key.

From the UI

1. Go to User Preferences → SSH Keys.
2. Click Add SSH Key.
3. Paste your ~/.ssh/id_rsa.pub or ~/.ssh/id_ed25519.pub.

From the CLI

maas admin sshkeys create "key=$(cat ~/.ssh/id_rsa.pub)"

Now, any machine deployed via MAAS will automatically have your SSH key injected.

4. Import Boot Resources

sudo maas admin boot-resources import
maas admin boot-resources read | jq '.[] | {name, type, architecture, complete}'

Check boot files:

ls /var/lib/maas/boot-resources/uefi/

5. Network Setup with UDM Pro

• Create a VLAN for MAAS provisioning.
• Assign DHCP or let MAAS handle it.

Example CLI setup:

maas admin fabrics read | jq '.[] | {id, name}'
maas admin vlans read 0 | jq '.[] | {id, name, vid, dhcp_on}'
maas admin vlan update 0 1 dhcp_on=true primary_rack=bareops
maas admin subnets create cidr=X.X.X.0/24 gateway_ip=X.X.X.X fabric=0 vlan=1

6. Commission & Deploy Nodes

Commission hardware:

maas admin machine commission <SYSTEM_ID>

Accept and mark as ready:

maas admin machine accept <SYSTEM_ID>
maas admin machine update <SYSTEM_ID> status=Ready

Deploy Ubuntu:

maas admin machine deploy <SYSTEM_ID> distro_series=jammy hwe_kernel=hwe-22.04

7. Enable Password Login on Deployed Ubuntu

By default, MAAS sets up SSH key authentication. To enable password login:

1. Edit SSH config:

   PasswordAuthentication yes
   PermitEmptyPasswords no
   UsePAM yes
   KbdInteractiveAuthentication yes
   

2. Create drop-in override:

   sudo mkdir -p /etc/ssh/sshd_config.d
   echo -e "PasswordAuthentication yes\nKbdInteractiveAuthentication yes" | \
   sudo tee /etc/ssh/sshd_config.d/01-password.conf
   

3. Restart SSH:

   sudo systemctl restart sshd
   

4. Set a password:

   sudo passwd ubuntu
   

Now you can log in with password auth, even via GUI clients like Remmina.

8. Troubleshooting

• DHCP/PXE issues → Double-check VLAN & UDM DHCP settings.
• Boot resources missing → Clear caches and re-import:

  sudo systemctl stop maas-regiond maas-rackd
  sudo rm -rf /var/lib/maas/regiond/cache/*
  sudo rm -rf /var/lib/maas/boot-resources/*
  sudo systemctl start maas-regiond maas-rackd
  sudo maas admin boot-resources import
  

• TFTP errors → Tail rackd logs:

  sudo tail -f /var/log/maas/rackd.log
  

✅ Conclusion

By combining MAAS with UDM Pro, you can bring cloud-like automation to your bare-metal infrastructure. From creating users and importing SSH keys to commissioning and PXE boot deployments, everything can be managed remotely—perfect for home labs, staging, or production environments.