REST result could not be parsed as JSON

I’ve got literally dozens, if not hundreds of messages just like this one, in my log file. Any way to track down which integration they might be connect to?

2020-07-16 13:03:23 WARNING (SyncWorker_3) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:03:53 WARNING (SyncWorker_11) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:04:24 WARNING (SyncWorker_5) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:04:55 WARNING (SyncWorker_1) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:05:26 WARNING (SyncWorker_0) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:05:57 WARNING (SyncWorker_11) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:06:28 WARNING (SyncWorker_4) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:06:59 WARNING (SyncWorker_11) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:07:30 WARNING (SyncWorker_16) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:08:01 WARNING (SyncWorker_15) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:08:32 WARNING (SyncWorker_7) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:09:03 WARNING (SyncWorker_9) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:09:34 WARNING (SyncWorker_9) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:10:05 WARNING (SyncWorker_9) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:10:36 WARNING (SyncWorker_11) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:11:07 WARNING (SyncWorker_1) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:11:38 WARNING (SyncWorker_12) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:12:09 WARNING (SyncWorker_18) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:12:40 WARNING (SyncWorker_4) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:13:11 WARNING (SyncWorker_11) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:13:42 WARNING (SyncWorker_0) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:14:13 WARNING (SyncWorker_11) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:14:44 WARNING (SyncWorker_9) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:15:15 WARNING (SyncWorker_12) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:15:46 WARNING (SyncWorker_16) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:16:17 WARNING (SyncWorker_6) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:16:48 WARNING (SyncWorker_10) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON
2020-07-16 13:17:19 WARNING (SyncWorker_2) [homeassistant.components.rest.sensor] REST result could not be parsed as JSON

Thanks!

homeassistant.components.rest.sensor
Do you have any REST sensors in your config?

The only REST sensor I’m using is Phil’s ha-dockermon: https://github.com/philhawthorne/ha-dockermon

One of those sensors looks like this:

  - platform: rest
    resource: !secret had-jabba-ha
    authentication: basic
    username: !secret had-jabba-user
    password: !secret had-jabba-pass
    name: Home-Assistant
    json_attributes:
      - status
    value_template: '{{ value_json.state }}'
    timeout: 30

If I try querying the actual URL, give it a valid username & password, I get JSON data in 30ms or so using postman. This integration has always just worked, and even produces the data I would expect.

Edit: suppose I can talk to Phil, and or open an issue with him on this. But it seems like a passive way of connecting the REST sensor to his container- wish there was a more concrete connection.