Knextancy - Node JS Multi Tenancy

At Bravi every project has multi tenant support since the beginning of the development. This because we have built a solution that is so easy to use that is almost imperceptible we are developing a multi tenant application. The only thing we have to care about is:

And that is it. You are already building a multi tenant application.

How does that work?

Well. The library knextancy takes care of everything for us.

Knextancy is built on top of knex and implements multi tenant using table prefixes. So all the clients share the same database but each one has it own table. For example:

Every time a request like this one below is done:

curl -X GET -H "x-client-id: 11" "http://localhost:3000/"

Knextancy will identify the tenant associated to that request based in the x-client-id. In case is the first request for that server, knextancy also will execute the migration and seed tasks. So there is no manual configuration required for bringing up a database for a new client.

You may ask yourself. How is that secure if the tenant is based in HTTP header? Then the user could change manually the tenant he is accessing.

Well. This is not a problem for services running inside a private network. For the public app/services, we run everything behind a proxy, that injects the x-client-id based in the domain.

After that knextancy injects in the request an instance of knex with the context of the current client (e.g. req.knex).

Then to execute any SQL query with multi tenant support is just required to use the req.knex and any table must have prefix $_ to allow knextancy resolve the table for the current client.

Simple example of how to build a multi tenant REST API. Using knextancy with express and PostgreSQL database.