If you are using an external and non-containerized PostgreSQL database, TrueSight Automation Console uses the default MD5 authentication to communicate with the database. You can change this authentication to SCRAM-SHA-256 before or after installing TrueSight Automation Console with an external and non-containerized PostgreSQL database.

To configure the SCRAM-SHA-256 authentication

Do the following:

1. Log in to the host where the external database is located.
2. Backup the following files: postgresql.conf and pg_hba.conf
   Example path:
   
   • /var/lib/pgsql/12/data/postgresql.conf
   • /var/lib/pgsql/12/data/pg_hba.conf
3. Update the postgreSQL.conf file:
   1. Navigate to the path where the file is available.
      Example path: /var/lib/pgsql/12/data/postgresql.conf

   2. In a text editor, open the postgresql.conf file, and replace md5 with scram-sha-256.

      #authentication timeout = 1min	# 1s-600s
      password encryption = scram-sha-256	# md5 or scram-sha-256
      #db_user_namespace = off

   3. Save the changes.

4. Update the pg_hba.conf file.
   1. Navigate to the path where the file is available.
      Example path: /var/lib/pgsql/12/data/pg_hba.conf

   2. In a text editor, open the pg_hba.conf file, and add the following section:

      To allow all the hosts for incoming connections

      #Accept from anywhere
      host	all	all	0.0.0.0/0	scram-sha-256

      or

      To allow only TSAC host and DB host for incoming connections

      #Allows only TSAC and DB host (DB host IP is required even if 127.0.0.1/32 (localhost) is added
      host all all TSAC_HOST_IP/32 scram-sha-256
      host all all DB_HOST_IP/32 scram-sha-256

   3. Save the changes.
5. Restart the external PostgreSQL database.
6. Log in to the database as a database user.
7. Do one of the following:
   • (TrueSight Automation Console is already installed)
     Run the following command to reset the password.
     1. • ALTER USER tsac_database_user PASSWORD '<password>';
        • ALTER USER postgres PASSWORD '<password>';
   • (TrueSight Automation Console is not installed)
     Modify the password of the PostgreSQL user:
     ALTER USER postgres PASSWORD '<password>';
8. Run the following command to confirm the authentication changes:
   SELECT rolname, rolpassword FROM "pg_authid";
9. Do one of the following:
   
   • Install TrueSight Automation Console. For details, see Installing.
   • Restart the TrueSight Automation Console application.
     • ./stackmanager stop -deployment=application
     • ./stackmanager start -deployment=application
10. Launch the TrueSight Automation Console console from the browser.

You can perform similar steps to revert to the MD5 authentication.