kill a forwarded TCP connection for https://github.com/cooperative-computing-lab/cctools/issues/714

.gitignore

# emacs
*~

# logs
parrot.log

action.sh

#! /bin/sh

# make a connection
ls -l $1

# zap & try again
./kill_socat_child.sh
ls -l $1
ret=$?
when=$(date +'%T.%3N')
echo "$when: exit code $ret"

# wait DISCONNECT_TIMEOUT + 5 && try again
echo "[now I sleep for the presumed value of DISCONNECT_TIMEOUT]"
sleep 305
when=$(date +'%T.%3N')
echo "$when: done waiting"
ls -l $1
ret=$?
when=$(date +'%T.%3N')
echo "$when: exit code $ret"

kill_socat_child.sh

#! /bin/sh

# Assuming a port-forwarder like
#    socat -d -d tcp4-listen:11247,fork,reuseaddr tcp4-connect:irods-host:1247
#
# kill the connection, without stopping the listener


# Written to Ubuntu Precise / procps 3.2.8 / coreutils 8.13

socats=$( pidof socat )
# expect a parent (listener) and a child (the connection to kill)

child=$( ps -o pid= --ppid "$socats" )
if [ -n "$child" ]; then
    when=$(date +'%T.%3N')
    kill -INT $child
    echo "$when: killed $child"
else
    echo "found nothing to kill (socat pids = $socats)" >&2
    exit 2
fi

provoke.sh

#! /bin/sh

# config for local server
export irodsEnvFile=~/.irods/irodsenv-test
server=irods-cgp-dev
export PATH=~/build/bin/:$PATH

echo '== what is it?'
which parrot_run
parrot_run --version

echo '== start port forward'
killall -INT socat
socat -d -d tcp4-listen:11247,fork,reuseaddr tcp4-connect:$server:1247 &
sleep 2

echo '== run parrot_run action.sh'
export PARROT_DEBUG_FLAGS="fatal error notice process  pstree  irods  remote  time pid"
parrot_run -o parrot.log ./action.sh /irods/localhost:11247/

echo '== tidy up'
killall -INT socat

echo '== show log parts'
perl -ne 'print if (m{ process: execve: /bin/ls succeeded} && print "[...]\n") .. m{ process: pid \d+ exited }' parrot.log