multi tenancy structure with node and sequelize

Question

I'm planning a multi tenancy app with nodejs and sequelize(mysql dialect). I'm gonna have a single app and multiple databases for each client. I'd need to connect to a client database after authentication (with passport.js). So there is a classic master database with clients info and db user,host and pwd, and then after the successful login the app connects to the specific client db. How could i do something like this? I was thinking to use sessions...maybe a middleware that for each request fetch the session and then passes the data to sequelize config object? Could anyone share with me how he/she manage to do something similar? I'm stuck in a logical trap ! Thank you

Answer 1

You're very close.

When you look up the user in your master db, in order to validate the username/password, you will also look up the connection string to the user-specific database. Then youu can create a simple express middleware function to open up the specific connection at the beginning of each request.

You will need usernames and passwords for the databases. For best security, they should not be the same as the users' usernames and passwords: If somebody cracks your web app and user table, you don't want them to have all the passwords.

But , what you propose is not classic multitenancy. Multitenancy is creating a single database, in which the various tables have columns mentioning which user they are for. Then once passport tells you the user's id, you can put it into your queries (for example, SELECT .... WHERE user_id = <<value>> AND ... .

Your proposal will work tolerably well for a few dozen users. But what happens if you get tens of thousands of users? That will be a lot of separate databases.