Support Genesis API Tokens

[MarcoHuebner]

Currently, the check_credentials function, called during selecting the database select_db_by_credentials (both in db), requires username and password to be set. However, this logic does not support token-based authentication for the GENESIS databases.

Suggestion(s):

• Distinguish between username and token e.g. via an is_token(username) function (by the length of the username...?) OR
• add a get_token(db_name) function.

[bergnerjonas]

I think there are a couple of options here:

1. Check if the username is a token via length: the tokens have a length of 32 according to the documentation. The only edge case I see is Zensus, here the username can be any E-Mail address, which might be 32 characters long.
2. Use the authentication endpoint (/helloworld/logincheck) and check the response. However, this would require parsing the response text itself (both authentication success and failure return 200 status codes) and might break everything if the api response changes.

Although option 2 seems to be the cleaner approach, I prefer option 1 for simplicity reasons. What do you think @pmayd ?

[pmayd]

I was first thinking one would be enough and simplistic but then I thought that the user should get an info if the credentials he or she entered are invalid so I think we should actually call check login for any new set_credentials and check what the user entered. This will not help if the user is changing the config directly but I think that is fine as this requires advanced knowledge anyway. So I would actually prefer to make this part of the set_credentials function

[bergnerjonas]

I was first thinking one would be enough and simplistic but then I thought that the user should get an info if the credentials he or she entered are invalid so I think we should actually call check login for any new set_credentials and check what the user entered. This will not help if the user is changing the config directly but I think that is fine as this requires advanced knowledge anyway. So I would actually prefer to make this part of the set_credentials function

Alright I will give it a try :)

[bergnerjonas]

I opened a PR that addresses this issue: #177