gomiddlewarenegroni

Different middleware for different routes in negroni

I want to have different middleware for different path. My current implementation is from this link 

UserRouter := mux.NewRouter().StrictSlash(true)
AdminRouter := mux.NewRouter().StrictSlash(true)

Router.HandleFunc("/apps/{app_name}/xyz", Handler).Methods("GET")

I created three different routers, so that I can assosiate them with different path and middleware 

nUserPath := negroni.New(middleware.NewAuthMiddleWare())
nUserPath.UseHandler(UserRouter)

nAdminPath := negroni.New()
nAdminPath.UseHandler(AdminRouter)

I created two different negroni instances and passed them the respective routers. As I wanted all this to run part of the same application on the same port so I created a Wrapper Router and negroni instance and associated them with the existing like below 

BaseRouter := mux.NewRouter().StrictSlash(true)
BaseRouter.Handle(UserBasePath,nUserPath) // UserBasePath is `/apps`
BaseRouter.Handle(HealthCheck,nUserPath)  // HealthCheck is `/health`
BaseRouter.Handle(AdminBasePath,nAdminPath) // AdminBasePath is `/Admin`

n := negroni.New(middleware.NewLogger()) // attached other common middleware here
n.UseHandler(router.BaseRouter)
n.Run(":8080")

Issues faced in this approach:
When I run /health it runs properly but when I run /apps/{app_name}/something I get a 404: Not Found

Note : I went through other approaches mentioned in below link but they don't satisfy my need.

- Route-specific Middlewares with Negroni

Solution

  • So, the issue with the above implementation is that BaseRouter.Handle() method take a path and not a path_matcher/template so all the url's which has path_length more than one were not working.

    I figured out two ways to achieve what I needed:
    First approach 

    // Create a rootRouter
var rootRouter *mux.Router = mux.NewRouter()

// Create as many subRouter you want with some prefix
var appsBasePath string = "/apps"
var adminBasePath string = "/admin"
upRouter := rootRouter.PathPrefix(appsBasePath).Subrouter()
apRouter := rootRouter.PathPrefix(adminBasePath).Subrouter()

// Register all the paths and mention middleware specifically for all of them
// Here middleware is a method with signature as
// func middleware( http.Handler) http.HandlerFunc {}

upRouter.Path("/test").Methods("POST").Handler(middleware(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request){
    fmt.Fprintf(w, "Welcome to the home page!")
})))

n := negroni.New(middleware.NewLogger()) // attached other common middleware here
n.UseHandler(rootRouter)
n.Run(":8080")

    Second approach
    This is extension/solution of the original issue in the question

    // Replace BaseRouter.handle() as below
// as PathPrefix takes a template so it won't have issue that we were facing  

BaseRouter.PathPrefix(UserBasePath).Handler(nUserPath)

    Thing to remember here is that within negroni nUserPath RequestContext of the middleware attached will be different from that of the actual router's HandlerMethod

    Note:
    By path length I mean something like this -- /abc or /abc/ has path_length=1 and /abc/xyz has path_length=2