We have to do our own linux system administration.
I agree, it's a bad idea, we're just developers.
But it's what we are stuck with for now.
Here's our crib sheet.

user admin

# adduser -p paSSwoRD aUser
# mkdir .ssh
# cd .ssh
# vi authorized_keys and paste in public key
# userdel -r aUser

groups

Here we append the dba group to the groups of the postgres user

sudo /usr/sbin/usermod -a -G dba postgres

sed

global search and replace

...