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Ansible roles reference

ansible/playbook_testbed.yml installs components that complement the upstream playbook_labgrid.yml. Each role maps to a tag so it can be run independently.

Quick reference

Role Tag Function Pre-requisite Post-check
virtual_mesh virtual_mesh Builds vwifi from source, installs QEMU, loads mac80211_hwsim CMake, git, kernel headers which vwifi-server, lsmod | grep mac80211_hwsim
arduino_relay arduino Deploys arduino daemon, udev rule for /dev/arduino-relay, systemd service Arduino Nano connected systemctl status arduino-relay-daemon
poe_switch poe_switch Installs labgrid-switch-abstraction via pipx, deploys poe_switch_control.py Switch reachable via SSH poe_switch_control.py status 1
wireguard wireguard Configures WireGuard SSH transport tunnel to openwrt-tests SSH gateway VM (global-coordinator hostname) Public key shared with gateway maintainer wg show
zerotier zerotier (via testbed) Installs ZeroTier and joins network 93afae5963ea9881 Node authorized at my.zerotier.com zerotier-cli info
wol wol Enables Wake-on-LAN on the host NIC at boot via systemd Correct interface in wol_interface ethtool enp0s25 | grep Wake
tftp_cleanup tftp_cleanup Systemd timer that prunes broken TFTP symlinks and orphan labgrid cache dirs TFTP dir at /srv/tftp systemctl status tftp-cleanup.timer
observability observability Prometheus node-exporter, autossh tunnels per DUT, Grafana dashboards DUTs reachable, Oracle VPS configured curl localhost:9100/metrics

Running the playbook

# Full testbed provisioning
ansible-playbook -i ansible/inventory/hosts.yml ansible/playbook_testbed.yml -K

# Single role by tag
ansible-playbook -i ansible/inventory/hosts.yml ansible/playbook_testbed.yml \
    --tags virtual_mesh -K

-K / --ask-become-pass is required because most roles install system packages and manage systemd units.

Role details

virtual_mesh

Installs the QEMU + vwifi stack required for virtual mesh tests:

  • Clones and builds vwifi with CMake
  • Installs qemu-system-x86, qemu-system-arm
  • Loads mac80211_hwsim at boot (via /etc/modules-load.d/)

Key variable: none (no defaults file; package names are hardcoded for Ubuntu).

arduino_relay

  • Deploys scripts/arduino/arduino_daemon.py to /usr/local/bin/
  • Installs configs/templates/arduino-relay-daemon.service to systemd
  • Writes a udev rule that creates /dev/arduino-relay symlink for the Arduino Nano's USB-serial adapter (matched by USB vendor/product ID)
  • Enables and starts the daemon

See Arduino relay for the channel map and CLI reference.

poe_switch

  • Installs labgrid-switch-abstraction via pipx
  • Copies scripts/switch/poe_switch_control.py to /usr/local/bin/
  • Creates ~/.config/switch.conf from the switch_password variable (set in ansible/inventory/group_vars/all.yml or passed via --extra-vars)

See PoE switch control for usage and troubleshooting.

wireguard

  • Generates a WireGuard key pair on the host if one does not exist
  • Renders /etc/wireguard/wg0.conf from a template with SSH gateway VM peer settings
  • Enables wg-quick@wg0 at boot

The lab's public key must be shared with the gateway VM maintainer (Aparcar) to be authorized in the VM's wg0.conf. See openwrt-tests onboarding.

zerotier

  • Runs the official ZeroTier install script
  • Joins network 93afae5963ea9881 (admin-only remote access)
  • Node must be authorized manually at my.zerotier.com

See ZeroTier remote access.

wol

  • Sets WakeOnLan=magic on wol_interface (default: enp0s25) via a systemd network drop-in
  • Verifies with ethtool that the NIC actually supports magic-packet WoL

The interface must match the host hardware. For the FCEFyN Lenovo T430 the interface is enp0s25.

See Wake-on-LAN setup.

tftp_cleanup

Systemd timer that runs daily and removes:

  • Broken symlinks under tftp_cleanup_tftp_dir (/srv/tftp)
  • Orphan labgrid cache dirs under tftp_cleanup_cache_dir (/var/cache/labgrid) — directories with no referencing symlink and older than tftp_cleanup_retention_days days (default 30)

Key defaults (ansible/roles/tftp_cleanup/defaults/main.yml):

tftp_cleanup_tftp_dir: /srv/tftp
tftp_cleanup_cache_dir: /var/cache/labgrid
tftp_cleanup_retention_days: 30
tftp_cleanup_schedule: "daily"
tftp_cleanup_dry_run: false

Set tftp_cleanup_dry_run: true to validate on a fresh host before enabling real deletions.

observability

  • Installs and starts prometheus-node-exporter on the orchestration host
  • Creates autossh systemd units that maintain reverse SSH tunnels from each DUT to a local port (19100–19105) for metrics scraping
  • Deploys Grafana dashboard provisioning files

See Observability for the full monitoring stack.

See also

  • Ansible / Labgrid — upstream playbook_labgrid.yml (exporter, places, SSH keys)
  • ansible/playbook_testbed.yml — playbook source with per-role tag comments