Shell Script to automate Create User and timestamps in PostgreSQL

Every quarter, the audit team requests a list of users and the timestamps of when they were created. So, I created a simple shell script to automate user creation and log the details into a table.
in this case I store the table in the testdb database

1) Create the table for store the data

CREATE TABLE user_log (
  username TEXT,
  created_at TIMESTAMP
);

2) This is the shell script (create_pg_user.sh)

#!/bin/bash

# Check if a username was provided
if [ -z "$1" ]; then
  echo "Usage: $0 <username>"
  exit 1
fi

USERNAME=$1
TIMESTAMP=$(date '+%Y-%m-%d %H:%M:%S')

PGUSER="postgres"
PGDATABASE="testdb"
PGHOST="localhost"
PGPORT="5432"

psql -U $PGUSER -d $PGDATABASE -h $PGHOST -p $PGPORT -c "CREATE USER $USERNAME;"

psql -U $PGUSER -d $PGDATABASE -h $PGHOST -p $PGPORT -c \
"INSERT INTO user_log (username, created_at) VALUES ('$USERNAME', '$TIMESTAMP');"

3) Execute the shell script. here I just put the username and the password will be auto generated.

sh create_pg_user.sh myuser
CREATE ROLE
INSERT 0 1
User created successfully!
Username: myuser
Password: k4EM99fNRdCC2spj

4) Let's check user created date

postgres=# \du
                                       List of roles
   Role name   |                         Attributes                         |  Member of
---------------+------------------------------------------------------------+--------------
 myuser           |                                                            | {}


testdb=# select * from user_log;
 username |     created_at
----------+---------------------
 myuser   | 2025-06-20 12:13:23

(2 rows)

so whenever the audit team asks when a user was created, we can provide the information by selecting user_log table