entrypoint script to take core files, and another script to take a stacktrace (while program is hung running, deadlocked / live-locked)

debug.sh

#!/bin/bash

# Tvheadend Debugging Guide
# https://tvheadend.org/projects/tvheadend/wiki/Debugging

_cleanup ()
{
	if [ "$core_pattern_orig" ]; then
		# Restore core path
		echo "$core_pattern_orig" > /proc/sys/kernel/core_pattern
	fi

	# Restore original file ownership and permissions
	chown -R ${crash_uid}:${crash_gid} /crash && chmod ${crash_rwx} /crash

  exit 0
}
trap _cleanup TERM INT QUIT HUP

# Remember the folder ownership for later
crash_uid="$(stat -c %u /crash)"
crash_gid="$(stat -c %g /crash)"
crash_rwx="$(stat -c %a /crash)"

# Set folder permissions
chown -R hts:video /config /recordings
chown -R hts:video /crash && chmod u+rwx /crash

if [ "$pipework_wait" ]; then
	echo "Waiting for pipework to bring up $pipework_wait..."
	pipework --wait -i $pipework_wait
fi

# Enable core dumps
ulimit -c unlimited
echo "Set: ulimit -c unlimited"

# Override core path
core_pattern_orig=$(cat /proc/sys/kernel/core_pattern)
core_pattern="/crash/core.%h.%e.%t"
echo "$core_pattern" > /proc/sys/kernel/core_pattern

# Make sure our core files get saved as '/crash/core*'
if [ "$?" -ne "0" ]; then
	echo "error: can't modify /proc/sys/kernel/core_pattern
Did you run this image with --privileged=true flag?"
fi

if [ "$(cat /proc/sys/kernel/core_pattern | grep -v -e '^/crash/core')" ]; then
	echo "error: the save path of core files is not /crash/core*
Aborting."
	exit 1
fi
echo "Set: core_pattern=/crash/core.%h.%e.%t"

# Uname
echo "uname -a:"
uname -a

# Dmesg
dmesg > /crash/dmesg
echo "Saved: dmesg --> /crash/dmesg"

# Start tvheadend
echo /usr/bin/tvheadend "$@"
     /usr/bin/tvheadend "$@"

# Echo full trace to stdout
tvh_pid="$(ps -o pid= -C tvheadend | head -1 | tr -d ' ')"
[ "${tvh_pid}" ] || exit 1
tail -n 99999 -F --pid=$tvh_pid /crash/tvheadend.log

# Restore core path
echo "$core_pattern_orig" > /proc/sys/kernel/core_pattern

# Keep debug binary with symbols
cp /usr/lib/debug/usr/bin/tvheadend /crash/tvheadend

# Restore original file ownership and permissions
chown -R ${crash_uid}:${crash_gid} /crash && chmod ${crash_rwx} /crash

# Exit cleanly if there was no segfault crash
core_file=$(find /crash/core.*)
[ "$core_file" ] || rm /crash/tvheadend && exit 0

echo "
***********************************************************************
GDB Backtrace
***********************************************************************
"
echo "set logging on /crash/gdb.txt
set pagination off
bt full" | gdb /usr/bin/tvheadend "$core_file"
echo "
***********************************************************************"
echo "
 Tvheadend Debugging Guide
 ----> https://tvheadend.org/projects/tvheadend/wiki/Debugging

 Tvheadend Issue Tracker
 ----> https://tvheadend.org/projects/tvheadend/issues

 Tvheadend New Issue
 ----> https://tvheadend.org/projects/tvheadend/issues/new
"

example-crane.yml

containers:
  tvheadend-debug:
    image: dreamcat4/tvheadend-debug
    dockerfile: tvheadend/Dockerfile.debug
    run:
      cmd: --abort
      volume:
        - /home/id/tvh_debug:/crash
      privileged: true

stacktrace.sh

#!/bin/bash

# Tvheadend Debugging Guide
# https://tvheadend.org/projects/tvheadend/wiki/Debugging

# Override core path
core_pattern_orig=$(cat /proc/sys/kernel/core_pattern)
core_pattern="/crash/core.%h.%e.%t"
echo "$core_pattern" > /proc/sys/kernel/core_pattern

# Remember the folder ownership for later
crash_uid="$(stat -c %u /crash)"
crash_gid="$(stat -c %g /crash)"
crash_rwx="$(stat -c %a /crash)"

# Set folder permissions
chown -R hts:video /crash && chmod u+rwx /crash

echo "
***********************************************************************
uname -a"
uname -a
echo "
***********************************************************************
ps -aux"
ps -aux
echo "
***********************************************************************
GDB Backtrace
***********************************************************************"
tvh_pid="$(ps -o pid= -C tvheadend)"
echo "set logging on
set pagination off
thread apply all bt full
generate core file" | gdb /usr/bin/tvheadend $tvh_pid

# Restore core path
echo "$core_pattern_orig" > /proc/sys/kernel/core_pattern

# Keep debug binary with symbols
cp /usr/lib/debug/usr/bin/tvheadend /crash/tvheadend

# Restore original file ownership and permissions
chown -R ${crash_uid}:${crash_gid} /crash && chmod ${crash_rwx} /crash

echo "
***********************************************************************"
echo "
 Tvheadend Debugging Guide
 ----> https://tvheadend.org/projects/tvheadend/wiki/Debugging

 Tvheadend Issue Tracker
 ----> https://tvheadend.org/projects/tvheadend/issues

 Tvheadend New Issue
 ----> https://tvheadend.org/projects/tvheadend/issues/new
"