Added method for changing default PostgreSQL passwords

docs/manual/host-configuration/index.md

@@ -50,6 +50,21 @@ used by the various components of LibreTime, run the following commands
     sudo systemctl restart airtime-celery
     sudo systemctl restart airtime_analyzer
 
+Changing the default PostgreSQL passwords
+----------------------------------------
+
+Two of the most important passwords that should be changed *immediately* after installation
+are the passwords used by the PostgreSQL database.
+It is strongly recommended that you do this before exposing your server to the internet beyond your internal network.
+
+1. Login to PostgreSQL with `sudo -u postgres psql`. `postgres=#` means that you have logged in successfully.
+2. Change the admin password with `ALTER USER postgres PASSWORD 'myPassword';`, where `myPassword` is the new password.
+Make sure to include the semicolon at the end! A response of `ALTER ROLE` means that the command ran successfully.
+3. Change the password for the *airtime* user with `ALTER USER airtime WITH PASSWORD 'new_password';`
+A response of `ALTER ROLE` means that the command ran successfully.
+4. If all is successful, logout of PostgreSQL with `\q`, go back to */etc/airtime/airtime.conf* to edit the password
+in the config file, and restart all services mentioned in the previous section.
+
 API client configuration
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