entrypoint.sh

#!/bin/sh
# Copyright 2020 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


start_client() {

  CMDSTRING="ls"

  echo $CMDSTRING
}

start_client 

# SIGUSR1-handler
my_handler() {
  exit 143; # 128 + 15 -- SIGTERM
}

# SIGTERM-handler
term_handler() {
  exit 143; # 128 + 15 -- SIGTERM
}

# setup handlers
# on callback, kill the last background process, which is `tail -f /dev/null` and execute the specified handler
trap 'kill ${!}; my_handler' SIGUSR1
trap 'kill ${!}; term_handler' SIGTERM

while true
do
  tail -f /dev/null & wait ${!}
done