👮‍ Auth

Two middlewares. One for general user authentication and one which makes routes exclusive for admins.

package main

import (
    "context"
    "errors"
    "fmt"
    "github.com/Gebes/there/v2"
    "github.com/Gebes/there/v2/header"
    "github.com/Gebes/there/v2/status"
    "log"
    "math/rand"
)

type User struct {
    Id    int    `json:"id,omitempty"`
    Name  string `json:"name,omitempty"`
    Admin bool   `json:"admin,omitempty"`
}

func DatabaseGetUserById(token string) (*User, error) {
    if len(token) != 12 {
        return nil, errors.New("no user found with that auth token")
    }
    return &User{
        Id:    rand.Int(),
        Name:  "Chris",
        Admin: true,
    }, nil
}

func main() {
    router := there.NewRouter()

    router.Group("/user").
        Get("/", UserGet).With(UserMiddleware)

    router.Group("/dashboard").
        Get("/", UserGet).With(UserAdminMiddleware)

    err := router.Listen(8080)

    if err != nil {
        log.Fatalf("Could not listen on port 8080: %v", err)
    }
}

func UserGet(request there.Request) there.Response {
    user, ok := request.Context().Value("user").(User)
    if !ok {
        return there.Error(status.UnprocessableEntity, errors.New("could not get user from context"))
    }
    return there.Json(status.OK, user)
}

func UserMiddleware(request there.Request, next there.Response) there.Response {
    authorization := request.Headers.GetDefault(header.RequestAuthorization, "")
    user, err := DatabaseGetUserById(authorization)
    if err != nil {
        return there.Error(status.Unauthorized, fmt.Errorf("not authorized: %w", err))
    }
    request.WithContext(context.WithValue(request.Context(), "user", user))
    return next
}

func UserAdminMiddleware(request there.Request, next there.Response) there.Response {
    authorization := request.Headers.GetDefault(header.RequestAuthorization, "")
    user, err := DatabaseGetUserById(authorization)
    if err != nil {
        return there.Error(status.Unauthorized, fmt.Errorf("not authorized: %w", err))
    }
    if !user.Admin {
        return there.Error(status.Forbidden, errors.New("you are not allowed to access this dashboard"))
    }
    request.WithContext(context.WithValue(request.Context(), "user", user))
    return next
}