Command line binary sensor on Dockerized HASS

Configuration
1

I would like to use a binary sensor to check my AC power. The server is an old thinkpad laptop, and I could use the AC Power Adaptor Status to figure it out. My problem is… that even with just an “echo 1” command, my sensor is always stuck at “OFF” state. My setup runs on docker-compose. What am I doing wrong ?

# AC Power Sensor
binary_sensor:
  - platform: command_line
    command: 'echo 1'
    name: "ACPower"
    scan_interval: 2
    value_template: '{% if value is equalto "1" %} OK {% else %} Power Outage {% endif %}'
    payload_on: '1'
    payload_off: '0'
2

Can you run the command on the device from within the HA container console and are able to get a result?