Server or Program Manager error after changing the REVEN user

To provide some context, the REVEN user is:

• With a Docker installation, reven
• With a native installation, <system-user-name> used to install REVEN

You may transparently change the user of your REVEN installation when migrating from a native installation to a Docker installation (or the opposite) or when moving a native installation from a system user to another.

In this case, two error conditions may arise:

• If REVEN versions are different before and after the change of user, starting REVEN with ./start.sh fails with the following error displayed in the terminal:

    django.db.utils.OperationalError: FATAL: role "my_username" does not exist
  

• If REVEN versions are identical, once started, the use of the Program Manager produces a 500 error, with a similar role error in the uwsgi.log file in the QUASAR_ROOT folder.

You can repair this manually by renaming the old_user to your new username, new_user in the database, using the following procedure. Keep in mind that if you run into this error, you likely have a kind of special setup. Therefore, this procedure may have to be adapted regarding your situation.

Note: if you are running the Docker installation, you can get a shell inside your container by running the following:
docker exec -it <container_name> bash

Here are the basic steps:

1. Make sure your REVEN’s Project Manager (Quasar), faulty, PostgreSQL is running:
   ./start.sh

2. Get the information about the running PostgreSQL:

   $ ps x | grep postgres
   [...]
   /usr/lib/postgresql/9.6/bin/postgres -D /home/<new_user>/Reven2/2.6.0-dev/db-2.6.0-dev.psql -k /tmp/tetrane-1000 -p 34567
   [...]
   							

   Here, the important information are the socket path (/tmp/tetrane-1000) and the port (34567).

3. Create a new superuser root in your DB:
   $ createuser -h /tmp/tetrane-1000 -p 34567 -U old_user --superuser root

4. Get a shell with this new superuser in your Project Manager’s DB (quasar):
   $ psql -h /tmp/tetrane-1000 -p 34567 -U root quasar

5. Rename your old_user to your new_user:

   quasar=# ALTER USER old_user RENAME TO new_user;
   ALTER ROLE
   

   Exit the pqsl shell with Ctrl-D.

6. Complete the procedure by restarting REVEN Project Manager:
   • With a Docker installation, run run.sh twice to stop and restart.
   • With a native installation, run stop.sh then start.sh.