[Icecast] Edited: <on-connect> / <on-disconnect> not working

Wed Sep 20 15:44:23 UTC 2023

Good morning,

On Wed, 2023-09-20 at 08:24 -0700, Jack Elliott wrote:
> Hi all,
> I am still trying to debug this. Summary, I am using <on-connect> in
> my icecast.xml to launch an email when a source-client connects. 
> Here is the line in icecast.xml:
> <on-connect>/home/kpovdjs/bin/email_onconnect.sh</on-connect>
> The problem is that this script doesn't do anything when icecast runs
> it. 
> The script works if I run it as user kpovdjs (me). But if I su to
> user icecast2, it does nothing. 
> "email_onconnect.sh" is:
> #!/bin/bash
> set -x
> 
> # thatjackelliott at kpov.org
> 
> printf "To: thatjackelliott at kpov.org\nFrom: kpovcomputer at gmail.com\nS
> ubject: Remote host has connected to mountpoint $1 on the
> Backstream\n\n KPOV Icecast server on IcecastPi has detected a
> connection on the backstream." > /home/kpovdjs/bin/on_connect.txt
> /usr/bin/msmtp thatjackelliott at kpov.org <
> /home/kpovdjs/bin/on_connect.txt  >/home/kpovdjs/bin/msmtp.log 2>&1

Your printf is wrong here.
NEVER do something like: printf "bla $blubb bla\n";
ALWAYS do: printf "bla %s bla\n" "$blubb";

That is exactly why we use printf in the first place. This is the
reason it exists.

Also you can just pipe your output between the commands. No need for a
tempfile (which also adds many problems, from permissions to race
conditions).

> If I run it as user kpovdjs (me), it sends the email, and this is the
> debug output: 
> kpovdjs at Icecast-Pi:~/bin $ ./email_onconnect.sh
> + printf 'To: thatjackelliott at kpov.org\nFrom: kpovcomputer at gmail.com\
> nSubject: Remote host has connected to mountpoint  on the
> Backstream\n\n KPOV Icecast server on IcecastPi has detected a
> connection on the backstream.'
> + /usr/bin/msmtp thatjackelliott at kpov.org
> But as user icecast2, the debug output is the same, but no email
> sent:
> icecast2 at Icecast-Pi:/home/kpovdjs/bin$ ./email_onconnect.sh
> + printf 'To: thatjackelliott at kpov.org\nFrom: kpovcomputer at gmail.com\
> nSubject: Remote host has connected to mountpoint  on the
> Backstream\n\n KPOV Icecast server on IcecastPi has detected a
> connection on the backstream.'
> + /usr/bin/msmtp thatjackelliott at kpov.org

Are you sure /usr/bin/msmtp works as the Icecast user?
Have you tried to run that script as the same user as Icecast?
e.g.: sudo -u icecast /path/to/script

> For debug purposes, I have rwxrwxrwx permission set from / and down
> to and including the script.
> -rwxrwxrwx  1 kpovdjs  kpovdjs  414 Sep 17 10:59 email_onconnect.sh

I hope that is a really really bad joke.

> For further debug purposes, I made a copy of the .sh script and
> chowned it to user icecast2.
> -rwxr-xr-x  1 icecast2 icecast  414 Sep 20 08:08
> email_onconnect_usericecast2.sh
> It also does not send the email when I invoke it as user icecast2.
> The "set -x" debug output is the same. 
> At this point it seems that this is not a icecast issue, per se, but
> some sneaky subtle weird annoying little Linux thing. However, if
> anyone here has an idea on how I might solve it, it would be very
> much appreciated.

Not the wording I would use.

You could check Icecast's error.log to see if it reports a problem.

Other than that you really first need to establish that the script
actually works running as that user.

> Thank you!
> ===========================
> 
> Very cool, I haven't encountered the "set -x" debug flag before.
> However, the output isn't as interesting as I hoped:
> 
> icecast2 at Icecast-Pi:/home/kpovdjs/bin$ ./email_onconnect.sh
> + printf 'To:thatjackelliott at kpov.org\nFrom:kpovcomputer at gmail.com\nS
> ubject: Remote host has connected to mountpoint on the Backstream\n\n
> KPOV Icecast server on IcecastPi has detected a connection on the
> backstream.'
> + /usr/bin/msmtpthatjackelliott at kpov.org
> icecast2 at Icecast-Pi:/home/kpovdjs/bin$
> 
> Thank you!
> 
> > Hi
> > 
> > For debuging purpose put
> > set -x in the row after #!/bin/bash
> > and execute the script. Post the whole output here.
> > 
> > Cheers
> > Tom
> > Am 17. Sept. 2023, 19:42 +0200 schrieb Jack Elliott <
> > that.jack.elliott at gmail.com>:
> > > Hi Jordan,
> > > 
> > > Here is my script:
> > > 
> > > #!/bin/bash
> > > 
> > > #thatjackelliott at kpov.org
> > > 
> > > printf "To:thatjackelliott at kpov.org\nFrom:kpovcomputer at gmail.com\
> > > nSubject: Remote host has connected to mountpoint $1 on the
> > > Backstream\n\n KPOV Icecast server on IcecastPi has detected a
> > > connection on the backstream." >
> > > /home/my_username/bin/on_connect.txt
> > > /usr/bin/msmtpthatjackelliott at kpov.org <
> > > /home/my_username/bin/on_connect.txt
> > > >/home/my_username/bin/msmtp.log 2>&1
> > > 
> > > This script has rwx set for everyone (for debugging).
> > > 
> > > Thank you!
> > > 
> > > --
> > > Jack Elliott
> > > Director of Classical Music Programming
> > > High Desert Community Radio
> > > KPOV Bend, Oregon
> > > On 9/17/23 8:25 AM, Jordan Erickson wrote:
> > > > Hi Jack,
> > > > 
> > > > You said:
> > > > 
> > > > ---
> > > > Okay now that I am user icecast2, let me see if the script I
> > > > want the Icecast server to run <on-connect> runs, so . . .
> > > > icecast2 at icecast-Pi: $ ./email_onconnect.sh
> > > > 
> > > > and the prompt returns immediately, no error message, but no
> > > > email received. But if I su back to my_username and try the
> > > > script, it runs and an email is received.
> > > > 
> > > > ---
> > > > 
> > > > This tells me that your script is not doing what it needs to do
> > > > as the Icecast user. Since you're doing it outside of Icecast,
> > > > it's not the <on-connect> or <on-disconnect> triggers that are
> > > > failing. It would be helpful if you could paste your script
> > > > (sensitive info like passwords removed) here.
> > > > 
> > > > 
> > > > Cheers,
> > > > Jordan
> > > > https://subj.am/

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