The Xplornet modem out at DR has decided to become unreliable and needs a sporadic restart. I’ve been pleased with how well the TP-Link Kasa HS105 Wifi switches perform so I just needed to figure out how to get HomeAssistant to reliably monitor the internet connection and reset it without inducing an infinite power-cycle loop. This is what I ended up with. Seems to work ok.

In configuration.yaml:

device_tracker:
  platform: ping
   hosts:
     google: 8.8.8.8
     beer: 67.205.176.146

In automations.yaml:

- id: Ensure Internet is on
    alias: Ensure Internet is on
    initial_state: on
    trigger:
      platform: state
      entity_id: switch.internet
      to: 'off'
      for:
        minutes: 1
  action:
    service: homeassistant.turn_on
    entity_id: switch.internet

id: Ensure Internet is on at HA startup
  alias: Ensure Internet is on at HA startup
  initial_state: on
  trigger:
    platform: homeassistant
    event: start
  action:
    service: homeassistant.turn_on
    entity_id: switch.internet

id: Restart internet connection
  alias: Restart internet connection
  initial_state: on 
  trigger: 
    - platform: state
      entity_id: device_tracker.google
      to: 'not_home'
    - platform: state
      entity_id: device_tracker.beer
      to: 'not_home'
  condition:
    condition: and
    conditions:
    - condition: state
      entity_id: device_tracker.google
      state: 'not_home'
    - condition: state
      entity_id: device_tracker.beer
      state: 'not_home'
  action:
    service: homeassistant.turn_off
    entity_id: switch.internet