How to supply password from shell script without using expect command - bash

Question

I'm writing a bash script to stop start my postgres DB service. Initially I succeeded in creating one, but as soon I enabled SSL certificate it prompts to enter the phrase password.
I know the easiest solution is to use expect , but in my environment i am not authorized to use it.
Can someone help me out in scripting as to how can I supply the PEM PHRASE password without a user intervention.
This is what I have worked so far.
-bash-4.2$ cat start_postgres_db.sh
cd `dirname $0`
. `dirname $0`/parameter.env
${POSTGREBIN}/pg_ctl -D ${POSTGREDATAPATH} start -w
while true
do
sleep 1
loopcnt=0
loopcnt=`expr ${loopcnt} + 1`
PRCCNT=`ps -ef | grep ${DBEXENAME} | grep -v grep|wc -l`
if [ ${PRCCNT} -eq 1 ]
then
echo "PostgreSQL process started sucessfully"
exit
fi
if [ ${loopcnt} -gt 11 ]
then
echo "PostgreSQL process not started successfully"
echo "su to postgres and run ${POSTGREBIN}/pg_ctl -D ${POSTGREDATAPATH} restart"
exit
fi
done
Execution:
bash-4.2$ ./start_postgres_db.sh
waiting for server to start....Enter PEM pass phrase:.........

Answer 1

You can provide a password to pg_ctl as argument on the command line with the option -P. I will assume it is contained in the variable ${POSTGREPASSWORD}.
start_postgres_db.sh
cd `dirname $0`
. `dirname $0`/parameter.env
${POSTGREBIN}/pg_ctl start -w -D ${POSTGREDATAPATH} -P ${POSTGREPASSWORD}
while true; do
sleep 1
(( loopcnt++ ))
PRCCNT=$(ps -ef | grep ${DBEXENAME} | grep -v grep | wc -l)
if [ ${PRCCNT} -eq 1 ]; then
echo "PostgreSQL process started sucessfully"
exit 0
fi
if [ ${loopcnt} -gt 11 ]; then
echo "PostgreSQL process not started successfully"
echo "su to postgres and run ${POSTGREBIN}/pg_ctl -D ${POSTGREDATAPATH} restart"
exit 1
fi
done