BUG #15961: psql should be able to read password from stdin

The following bug has been logged on the website:

Bug reference:      15961
Logged by:          Robert Patrick
Email address:      rhpatrick@gmail.com
PostgreSQL version: 11.4
Operating system:   Amazon Linux
Description:

I understand why psql does not include a mechanism to pass the password on
the command-line.  Having worked with and built other similar applications
at Oracle, I tried to pipe the password into stdin of the psql command like
so:  

echo P0stgr3s | psql --username=postgres

Unfortunately, psql ignores it and prompts me for the password.

My use case is that I am writing terraform scripts to standup Sonarqube in
AWS.  After creating the AWS RDS PostgreSQL database, I need to be able to
create the sonarqube user and grant access to the sonarqube database that
was created with the RDS instance.  I can work around this using the
PGPASSWORD environment variable but that seems to be deprecated.  I don't
want to use the .pgpass solution since I don't want/need the postgres user's
credentials in my EC2 instance where the Sonarqube server will be running...
 

psql should really accept the value for the password prompt from stdin.