Code loosing connection

[Schmeling-M]

When I do this in my code:
if Client.status()['state'] == "play":

I get this:
Apr 14 08:34:14 moode systemd[1]: Stopped Music Player Daemon.
Apr 14 08:34:14 moode systemd[1]: Started Music Player Daemon.
Apr 14 08:34:14 moode rc.local[481]: Traceback (most recent call last):
Apr 14 08:34:14 moode rc.local[481]: File "/home/pi/ampcontroller.py", line 196, in
Apr 14 08:34:14 moode rc.local[481]: if Client.status()['state'] == "play": # Playing or Airplay active
Apr 14 08:34:14 moode rc.local[481]: File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 469, in mpd_command
Apr 14 08:34:14 moode rc.local[481]: return wrapper(self, name, args, callback)
Apr 14 08:34:14 moode rc.local[481]: File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 532, in _execute
Apr 14 08:34:14 moode rc.local[481]: return retval()
Apr 14 08:34:14 moode rc.local[481]: File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 454, in command_callback
Apr 14 08:34:14 moode rc.local[481]: res = function(self, self._read_lines())
Apr 14 08:34:14 moode rc.local[481]: File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 394, in _parse_object
Apr 14 08:34:14 moode rc.local[481]: objs = list(self._parse_objects(lines))
Apr 14 08:34:14 moode rc.local[481]: File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 240, in _parse_objects
Apr 14 08:34:14 moode rc.local[481]: for key, value in self._parse_pairs(lines):
Apr 14 08:34:14 moode rc.local[481]: File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 235, in _parse_pairs
Apr 14 08:34:14 moode rc.local[481]: for line in lines:
Apr 14 08:34:14 moode rc.local[481]: File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 586, in _read_lines
Apr 14 08:34:14 moode rc.local[481]: line = self._read_line()
Apr 14 08:34:14 moode rc.local[481]: File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 571, in _read_line
Apr 14 08:34:14 moode rc.local[481]: raise ConnectionError("Connection lost while reading line")
Apr 14 08:34:14 moode rc.local[481]: mpd.base.ConnectionError: Connection lost while reading line
Apr 14 08:34:14 moode systemd[1]: rc-local.service: Control process exited, code=exited, status=1/FAILURE
Apr 14 08:34:14 moode systemd[1]: Created slice system-bluealsa\x2daplay.slice.
Apr 14 08:34:14 moode systemd[1]: Started BlueAlsa-Aplay.
Apr 14 08:34:14 moode systemd[1]: rc-local.service: Failed with result 'exit-code'.
Apr 14 08:34:14 moode systemd[1]: Failed to start /etc/rc.local Compatibility.

In the beginning of my code, I connect to mpd like so:
Client = mpd.MPDClient() # create client object
Client.timeout = None
Client.idletimeout = None

while True:
try:
Client.connect("localhost", 6600) # connect to localhost:6600
except:
continue
break

It seems like I get a connection error, but how do I solve this, and why am I loosing the connection???

[Mic92]

Mpd is closing connections after a some timeout if your client is not doing anything. see #90

I cannot see the whole program so it is hard to tell what your pattern in the library is.

[Schmeling-M]

I'm starting the code from etc/rc.local, so it starts immediately, and the error likewise, it seems. I have set the timeouts to none, So I wouldn't expect the connection to be closed that fast, but I might be wrong. The entire code is below:

(The formatting is really annoying me, and I cant fix it, I have atatched the file as well, renamed .txt)
ampcontroller.txt

[Mic92]

Sorry this is not readable without proper indentation. If you could upload a repo or gist, I might have a look...

[Schmeling-M]

Yes, terribly sorry about that. I uploaded a gist instead. It seems to be working. Please let me know if it doesn't.

https://gist.github.com/Schmeling-M/3be163d0bf6fb3ac520df6dd9dc8ed54

One thing, that especially pussels me is that the raised exception in base.py, line 571 is raised because of this condition in line 569: if not line.endswith("\n"): Is this because the lack of "\n" means, that the connection to mpd is lost or.....?

I should also mention, that the code is running on a Rpi4B with moode from moodeaudio.org. When the code is running, moode audio spits out the following error 3-5 times at startup: "MPD error JSON.parse: unexpected end of data at line 1 column 1 of the JSON data". I seems it could have a relation to the exception raised in base.py

[Mic92]

If read returns an empty string, this is detected as connection lost.

I cannot see any obvious bug right now, but maybe check if the following code works for your:

import logging, mpd
logging.basicConfig(level=logging.DEBUG)
client = mpd.MPDClient()
client.connect("localhost", 6600)
print(client.status())

[Schmeling-M]

I take it, your suggestion doesn't solve the problem. Only debugs it further, correct?

[Mic92]

Is mpd actually listening on this port?

You can run tcpdump to see what is going on the wire:

$ sudo tcpdump -i any localhost port 6600 -n -A

And than run in another terminal, the same script.

[Mic92]

Also I would not run this code anywhere where untrusted clients have access to:
It is full of shell injection bugs: https://github.com/moode-player/moode/blob/653bbb46f44851050e74a5c86693603ad9c14ea7/www/command/moode.php#L272

[Schmeling-M]

Thankyou for all the suggestions and feedback. I'll test the connection in the following days, and see, if that might be the problem.

Fortunately the player is on a private lan. No untrusted clients have access.

[Schmeling-M]

It seems, I have a connection to mpd. At least I get the correct info, when running your python code:
this
import logging, mpd logging.basicConfig(level=logging.DEBUG) client = mpd.MPDClient() client.connect("localhost", 6600) print(client.status())

gives this
root@moode:/home/pi# python3 mpd_test.py INFO:mpd.base:Calling MPD connect('localhost', 6600, timeout=None) DEBUG:mpd.base:Calling MPD status() {'volume': '0', 'repeat': '0', 'random': '0', 'single': '0', 'consume': '0', 'partition': 'default', 'playlist': '2', 'playlistlength': '3', 'mixrampdb': '0.000000', 'state': 'play', 'song': '1', 'songid': '2', 'time': '979:1550', 'elapsed': '979.219', 'bitrate': '192', 'duration': '1550.294', 'audio': '44100:24:2', 'nextsong': '2', 'nextsongid': '3'}

So I'm guessing, the connection works initially, but with timeout set to none, I cant see why the connection i suddenly lost??

[Schmeling-M]

my mpd config /etc/mpd.conf looks like so:
`root@moode:/etc# cat mpd.conf
#########################################
This file is automatically generated
by the MPD configuration page.
#########################################

music_directory "/var/lib/mpd/music"
playlist_directory "/var/lib/mpd/playlists"
db_file "/var/lib/mpd/database"
log_file "/var/log/mpd/log"
pid_file "/var/run/mpd/pid"
state_file "/var/lib/mpd/state"
sticker_file "/var/lib/mpd/sticker.sql"
user "mpd"
group "audio"
bind_to_address "any"
port "6600"
log_level "default"
restore_paused "yes"
auto_update "no"
follow_outside_symlinks "yes"
follow_inside_symlinks "yes"
zeroconf_enabled "no"
zeroconf_name "Moode MPD"
filesystem_charset "UTF-8"
metadata_to_use "+comment"
replaygain "off"
replaygain_preamp "0"
volume_normalization "no"
audio_buffer_size "4096"
max_output_buffer_size "131072"
max_playlist_length "16384"
max_connections "128"

decoder {
plugin "ffmpeg"
enabled "yes"
}

input {
plugin "curl"
}

resampler {
plugin "soxr"
quality "high"
threads "1"
}

audio_output {
type "alsa"
name "ALSA Default"
device "hw:0,0"
mixer_type "software"
dop "no"
}

audio_output {
type "alsa"
name "ALSA Crossfeed"
device "crossfeed"
mixer_type "software"
dop "no"
}

audio_output {
type "alsa"
name "ALSA Parametric EQ"
device "eqfa12p"
mixer_type "software"
dop "no"
}

audio_output {
type "alsa"
name "ALSA Graphic EQ"
device "alsaequal"
mixer_type "software"
dop "no"
}

audio_output {
type "alsa"
name "ALSA Polarity Inv"
device "invpolarity"
mixer_type "software"
dop "no"
}

audio_output {
type "alsa"
name "ALSA CamillaDSP"
device "camilladsp"
mixer_type "software"
dop "no"
}

audio_output {
type "alsa"
name "ALSA Bluetooth"
device "btstream"
mixer_type "software"
}

audio_output {
type "httpd"
name "HTTP Server"
port "8000"
encoder "lame"
bitrate "320"
tags "yes"
always_on "yes"
}

root@moode:/etc#
`

[Mic92]

timeout is already None by default... you don't even need to set it.

[Schmeling-M]

Perhaps, I should try to run you python code in a loop, like my code, and see if that will reproduce the error?

[Schmeling-M]

I think I found the problem. If I run this code:

https://gist.github.com/Schmeling-M/ae67c0b82f804dfcf65bc3f8a4d0081e

It runs perfectly, until I connect to moode via bluetooth, in which case, it spits out exactly the same error as before

DEBUG:mpd.base:Calling MPD status()
DEBUG:mpd.base:Calling MPD status()
{'volume': '0', 'repeat': '0', 'random': '0', 'single': '0', 'consume': '0', 'partition': 'default', 'playlist': '2', 'playlistlength': '7', 'mixrampdb': '0.000000', 'state': 'play', 'song': '6', 'songid': '7', 'time': '335:335', 'elapsed': '334.685', 'bitrate': '32', 'duration': '334.889', 'audio': '44100:24:2'}
DEBUG:mpd.base:Calling MPD status()
DEBUG:mpd.base:Calling MPD status()
{'volume': '0', 'repeat': '0', 'random': '0', 'single': '0', 'consume': '0', 'partition': 'default', 'playlist': '2', 'playlistlength': '7', 'mixrampdb': '0.000000', 'state': 'play', 'song': '6', 'songid': '7', 'time': '335:335', 'elapsed': '334.788', 'bitrate': '32', 'duration': '334.889', 'audio': '44100:24:2'}
DEBUG:mpd.base:Calling MPD status()
DEBUG:mpd.base:Calling MPD status()
INFO:mpd.base:Calling MPD disconnect()
Traceback (most recent call last):
File "mpd_test2.py", line 15, in
print(client.status())
File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 469, in mpd_command
return wrapper(self, name, args, callback)
File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 532, in _execute
return retval()
File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 454, in command_callback
res = function(self, self._read_lines())
File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 394, in _parse_object
objs = list(self._parse_objects(lines))
File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 240, in _parse_objects
for key, value in self._parse_pairs(lines):
File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 235, in _parse_pairs
for line in lines:
File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 586, in _read_lines
line = self._read_line()
File "/usr/local/lib/python3.7/dist-packages/mpd/base.py", line 571, in _read_line
raise ConnectionError("Connection lost while reading line")
mpd.base.ConnectionError: Connection lost while reading line
root@moode:/home/pi#

So it seems that the error is natural, but why it occurs at startup, when I run the script from etc/rc.local I do not know.It could perhaps be because bluetooth forces an mpd disconnect, but I'm not sure.

Do you have any idea, as to why this might be happening?

[Mic92]

not really no.

[Mic92]

I don't really see any actionable insights on what is broken here in the library. This seems more a setup issue.