log () {

echo "$(date +'%Y/%m/%d %H:%M:%S') $@"

}

WAIT_TIMEOUT=${WAIT_TIMEOUT:-10}

CONN_HOLD=${CONN_HOLD:-3}

timeout_exec=$(basename "$(readlink $(which timeout))")

if [ "$timeout_exec" = "busybox" ]

log "using busybox"

_using_busybox=1

log "not using busybox"

_using_busybox=0

for endpoint in $(echo $WAIT_HOSTS | tr "," "\n")

host=${endpoint%:*}

port=${endpoint#*:}

_start_time=$(date +%s)

while true

do

_now=$(date +%s)

_run_time=$(( $_now - $_start_time ))

if [ $_run_time -gt $WAIT_TIMEOUT ]

then

log "timed out waiting for $endpoint"

exit 1

fi

log "waiting for $endpoint to become up..."

# connect and see if connection stays up.

# docker-proxy can listen to ports before the actual service is up,

# in which case it will accept and then close the connection again.

# this checks not only if the connect succeeds, but also if the

# connection stays up for $CONN_HOLD seconds.

if [ $_using_busybox -eq 1 ]

then

timeout -t $CONN_HOLD busybox nc $host $port -e busybox sleep $(( $CONN_HOLD + 1 ))

retval=$?

# busybox-timeout on alpine returns 0 on timeout

expected=143

else

timeout $CONN_HOLD nc $host $port

retval=$?

# coreutils-timeout returns 124 if it had to kill the slow command

expected=124

fi

if [ $retval -eq $expected ]

then

log "$endpoint is up. maintained connection for $CONN_HOLD seconds!"

break

else

log "returned value $retval, expecting $expected"

fi

sleep 1

done

exec $@