fixed issue #801 , support canal docker

docker/image/alidata/lib/proc.sh

@@ -0,0 +1,40 @@
+# waitterm
+#   wait TERM/INT signal.
+#   see: http://veithen.github.io/2014/11/16/sigterm-propagation.html
+waitterm() {
+	local PID
+	# any process to block
+	tail -f /dev/null &
+	PID="$!"
+	# setup trap, could do nothing, or just kill the blocker
+	trap "kill -TERM ${PID}" TERM INT
+	# wait for signal, ignore wait exit code
+	wait "${PID}" || true
+	# clear trap
+	trap - TERM INT
+	# wait blocker, ignore blocker exit code
+	wait "${PID}" 2>/dev/null || true
+}
+
+# waittermpid "${PIDFILE}".
+#   monitor process by pidfile && wait TERM/INT signal.
+#   if the process disappeared, return 1, means exit with ERROR.
+#   if TERM or INT signal received, return 0, means OK to exit.
+waittermpid() {
+	local PIDFILE PID do_run error
+	PIDFILE="${1?}"
+	do_run=true
+	error=0
+	trap "do_run=false" TERM INT
+	while "${do_run}" ; do
+		PID="$(cat "${PIDFILE}")"
+		if ! ps -p "${PID}" >/dev/null 2>&1 ; then
+			do_run=false
+			error=1
+		else
+			sleep 1
+		fi
+	done
+	trap - TERM INT
+	return "${error}"
+}