example_overall_test.go

package rye_test

import (
	"context"
	"errors"
	"fmt"
	"net/http"

	"github.com/InVisionApp/rye"
	log "github.com/sirupsen/logrus"
	"github.com/cactus/go-statsd-client/statsd"
	"github.com/gorilla/mux"
)

func Example_basic() {
	statsdClient, err := statsd.NewBufferedClient("localhost:12345", "my_service", 1.0, 0)
	if err != nil {
		log.Fatalf("Unable to instantiate statsd client: %v", err.Error())
	}

	config := rye.Config{
		Statter:  statsdClient,
		StatRate: 1.0,
	}

	middlewareHandler := rye.NewMWHandler(config)

	middlewareHandler.Use(beforeAllHandler)

	routes := mux.NewRouter().StrictSlash(true)

	routes.Handle("/", middlewareHandler.Handle([]rye.Handler{
		middlewareFirstHandler,
		homeHandler,
	})).Methods("GET")

	// If you perform a `curl -i http://localhost:8181/cors -H "Origin: *.foo.com"`
	// you will see that the CORS middleware is adding required headers
	routes.Handle("/cors", middlewareHandler.Handle([]rye.Handler{
		rye.MiddlewareCORS(),
		homeHandler,
	})).Methods("GET", "OPTIONS")

	// If you perform an `curl -i http://localhost:8181/jwt \
	// -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWV9.TJVA95OrM7E2cBab30RMHrHDcEfxjoYZgeFONFh7HgQ"
	// you will see that we are allowed through to the handler, if the sample token is changed, we will get a 401
	routes.Handle("/jwt", middlewareHandler.Handle([]rye.Handler{
		rye.NewMiddlewareJWT("secret"),
		getJwtFromContextHandler,
	})).Methods("GET")

	routes.Handle("/error", middlewareHandler.Handle([]rye.Handler{
		middlewareFirstHandler,
		errorHandler,
		homeHandler,
	})).Methods("GET")

	// In order to pass in a context variable, this set of
	// handlers works with "ctx" on the query string
	routes.Handle("/context", middlewareHandler.Handle(
		[]rye.Handler{
			stashContextHandler,
			logContextHandler,
		})).Methods("GET")

	log.Infof("API server listening on %v", "localhost:8181")

	srv := &http.Server{
		Addr:    "localhost:8181",
		Handler: routes,
	}

	srv.ListenAndServe()
}

func beforeAllHandler(rw http.ResponseWriter, r *http.Request) *rye.Response {
	log.Infof("This handler is called before every endpoint: %+v", r)
	return nil
}

func homeHandler(rw http.ResponseWriter, r *http.Request) *rye.Response {
	log.Infof("Home handler has fired!")

	fmt.Fprint(rw, "This is the home handler")
	return nil
}

func middlewareFirstHandler(rw http.ResponseWriter, r *http.Request) *rye.Response {
	log.Infof("Middleware handler has fired!")
	return nil
}

func errorHandler(rw http.ResponseWriter, r *http.Request) *rye.Response {
	log.Infof("Error handler has fired!")

	message := "This is the error handler"

	return &rye.Response{
		StatusCode: http.StatusInternalServerError,
		Err:        errors.New(message),
	}
}

func stashContextHandler(rw http.ResponseWriter, r *http.Request) *rye.Response {
	log.Infof("Stash Context handler has fired!")

	// Retrieve the request's context
	ctx := r.Context()

	// A query string value to add to the context
	toContext := r.URL.Query().Get("ctx")

	if toContext != "" {
		log.Infof("Adding `query-string-ctx` to request.Context(). Val: %v", toContext)
	} else {
		log.Infof("Adding default `query-string-ctx` value to context")
		toContext = "No value added. Add querystring param `ctx` with a value to get it mirrored through context."
	}

	// Create a NEW context
	ctx = context.WithValue(ctx, "query-string-ctx", toContext)

	// Return that in the Rye response
	// Rye will add it to the Request to
	// pass to the next middleware
	return &rye.Response{Context: ctx}
}

func logContextHandler(rw http.ResponseWriter, r *http.Request) *rye.Response {
	log.Infof("Log Context handler has fired!")

	// Retrieving a context value is EASY in subsequent middlewares
	fromContext := r.Context().Value("query-string-ctx")

	// Reflect that on the http response
	fmt.Fprintf(rw, "Here's the `ctx` query string value you passed. Pulled from context: %v", fromContext)
	return nil
}

// This handler pulls the JWT from the Context and echoes it through the request
func getJwtFromContextHandler(rw http.ResponseWriter, r *http.Request) *rye.Response {
	log.Infof("Log Context handler has fired!")

	jwt := r.Context().Value(rye.CONTEXT_JWT)
	if jwt != nil {
		fmt.Fprintf(rw, "JWT found in Context: %v", jwt)
	}
	return nil
}