How do I access the app_data in actix_web's Guard::check() function?

Question

I am trying to implement a custom guard that checks if the authorization token is valid:

impl Guard for AuthGuard {
    fn check(&self, ctx: &GuardContext<'_>) -> bool {
        // check header value here
        // and retrieve connection pool from app_data
    }
}

Answer 1

Taking a look at GuardContext, you can see that there is req_data and head. And hence one can do.

impl Guard for AuthGuard {
    fn check(&self, ctx: &GuardContext<'_>) -> bool {
        let jwt = ctx.req_data::<Jwt>().unwrap();
        let token = ctx.head().headers().get(header::AUTHORIZATION).unwrap();
        jwt.is_valid(token)
    }
}

The things you are asking for are there but remember that Checks are blocking.

• Checks can be good to check whether a token exists and its valid.
• Checks are not suitable in a scenario where you need to check if a token exists in Redis or sqlx pool.

If you need to do async stuff you might need to think of FromRequest or middleware. See this question.