Health Daemon Overview

Overview

The purpose of this daemon is to monitor the health of all of the other services and translate them into signals via 3 physical LED lights. There are 3 lights this will control:

• Temp:
  • Off - No power, completely disconnected
  • Red - Daemon reporting an error
  • Orange, Solid - Daemon reporting a warning
  • Orange, slow blinking - No temp sensors connected
  • Orange, rapid blinking - Some temp sensors connected
  • Green - Temp daemon reporting temps across all sensors
• Control:
  • Off - No power, completely disconnected
  • Red - Daemon reporting an error
  • Orange - Daemon reporting a warning
  • Green - Control daemon working properly
• Web:
  • Off - No power, completely disconnected
  • Red - Daemon reporting an error
  • Warning - Daemon reporting a warning
  • Green - Web interface up and working properly

Health for each service should be monitored in the following ways:

• Temp - Read Redis health state and subscribe to temp events
  • if there are no temp events within the last 10 seconds, set LED to red
  • if there is an error reported, set LED to red
  • if there is a warning reported, set LED to orange
  • use the sensor-connected logic above in the case that any sensors are not listed
  • otherwise, set LED to green
• Control - Read control health status from redis. Health should indicate:
  • Healthy - Green LED
  • Warning reported - Orange LED
  • Error reported - Red LED
  • Any health status timestamp older than 10 seconds - Orange LED
  • Any health status timestamp older than 1 minute - Red LED
• Web
  • Http request to API health endpoint every 5 seconds
    • Healthy - Green LED
    • Warning reported - Orange LED
    • Error reported - Red LED
  • Http request to index every 5 seconds
    • On 2xx status - Green LED
    • On error status - Red LED
    • on response lasting longer than 1 second - Orange LED