.local domains returns OSError: 0

[wifijt]

I was trying to use the home assistant API and I ran into an issue using the homeassistant.local domain in the fetch request. This caused an OSError 0

Retrieving data...Traceback (most recent call last):
File "code.py", line 30, in
File "code.py", line 27, in
File "adafruit_magtag/magtag.py", line 174, in fetch
File "adafruit_portalbase/init.py", line 365, in fetch
File "adafruit_portalbase/network.py", line 523, in fetch_data
File "adafruit_portalbase/network.py", line 442, in fetch
File "adafruit_requests.py", line 595, in get
File "adafruit_requests.py", line 559, in request
File "adafruit_requests.py", line 419, in _get_socket
OSError: 0

The workaround is to use the IP address of the server.

[anecdata]

.local domains seem to resolve in general in the socketpool module:

Adafruit CircuitPython 6.1.0-rc.1 on 2021-01-19; FeatherS2 with ESP32S2
>>> import wifi
>>> import socketpool
>>> from secrets import secrets
>>>
>>> pool = socketpool.SocketPool(wifi.radio)
>>> wifi.radio.connect(secrets["ssid"], secrets["password"])
>>> wifi.radio.ap_info.rssi
-51
>>> wifi.radio.ipv4_dns
1.1.1.2
>>> pool.getaddrinfo("desktop.local", 443)
[(0, 0, 0, '', ('192.168.1.32', 443))]

One possibility is a LAN DNS proxy or something else interfering with the name resolution.

[wifijt]

Hmm it's something about the homeassistant.local mdns query because other .local domains resolve

pool.getaddrinfo("wind.local",443)
[(0, 0, 0, '', ('192.168.1.201', 443))]
pool.getaddrinfo("homeassistant.local",443)
Traceback (most recent call last):
File "", line 1, in
OSError: 0

[tannewt]

I'm not sure we have mDNS enabled.

[dhalbert]

@tannewt This bug is fixed by the new mDNS code?

[tannewt]

The original poster is using ESP32SPI, not a native ESP build.