https://github.com/oracle/docker-images/blob/master/OracleDatabase/dockerfiles/12.1.0.2/runOracle.sh

# Set SIGINT handler
trap _int SIGINT

# Set SIGTERM handler
trap _term SIGTERM

# Set SIGKILL handler
trap _kill SIGKILL

########### SIGINT handler ############
function _int() {
   echo "Stopping container."
   echo "SIGINT received, shutting down database!"
   sqlplus / as sysdba <<EOF
   shutdown immediate;
EOF
   lsnrctl stop
}

########### SIGTERM handler ############
function _term() {
   echo "Stopping container."
   echo "SIGTERM received, shutting down database!"
   sqlplus / as sysdba <<EOF
   shutdown immediate;
EOF
   lsnrctl stop
}

########### SIGKILL handler ############
function _kill() {
   echo "SIGKILL received, shutting down database!"
   sqlplus / as sysdba <<EOF
   shutdown abort;
EOF
   lsnrctl stop
}