Stefan, that blogpost helped a lot - thanks!
Just in case someone finds this and needs the a UI password reset, too - like I did.
Follow this guide:
1) Login on the CLI via SSH, admin user
2) become superuser (root password):
su -
3) find the docker container ID that is your database:
docker ps -f name=db
4) on the output, we need the container ID for the next command. mine was "xxx"
5) start a shell in that docker instance
docker exec -it xxx bash
6)open the DB
psql -U postgres
7) connect to the database atlantis
\c atlantis
just to verify/backup, get the currently stored hash of the password. The example gets the hash for the user "admin".
SELECT password_digest FROM users WHERE uid='xxx';
9) generate a new hash for the desired password. I used python on my linux box. You choose your weapon.
python3 -c 'import bcrypt; passwort=str.encode("yourNewPasswordHere"); print(bcrypt.hashpw(passwort, bcrypt.gensalt(rounds=12)))'
10)update the digest with the new value.
UPDATE users SET password_digest = 'xxx' WHERE uid = 'xxx';
Login with the new password on the UI.
