How to access Request Specific Data in Go?

Question

I have an API written in go and I am using the gin-gonic framework to implement my endpoints. I am following clean architecture for my project which means that my entire application is divided into multiple layers namely - Controller, Service, Repository, And Session. The endpoints are secured by auth0 and the validation is carried out in a gin middleware. In the middleware I can extract the Subject from the JWT (Set in the header)

Now, here's my question. I want to use this subject value in my queries. I was wondering if I can store the Subject (sub) in the context and use it in other parts of my code WITHOUT PASSING CONTEXT AROUND. Is this possible? Or do I simply have to update all my functions and add a new parameter "Sub" to all downstream calls?

I am alluding to using a Global Variable of sorts to access Request Specific Data (SUB from the JWT token). I know it's a bad practice- I am just wondering if there is any other way to accomplish this other than passing around request specific data? Any help is appreciated.

Answer 1

It is really the whole point of the context - it exists to hold these kinds of things and to be passed around the chain. It's important because you want to keep it scoped to the request -- if you start using globals you could run into issues where you get contention because multiple requests are messing with the same data. Likewise if the token was invalidated between requests.

If your authentication middleware runs before your query (which it sounds like it does) then it should be simply a matter of having it put the subject in the context in a way you're happy with.