vendored

cmd/api/main.go

@@ -4,10 +4,13 @@ import (
 	"context"
 	"log"
 	"strings"
+	"expvar"
+	"runtime"
 
 	//"html/template"
 	"flag"
 	"net/http"
+	"fmt"
 
 	"github.com/gorilla/websocket"
 
@@ -23,7 +26,8 @@ import (
 	"party.at/party/internal/jsonlog"
 )
 
-const version = "1.0.0"
+var version string
+var buildTime string
 
 type config struct {
 	port int
@@ -102,8 +106,16 @@ func main() {
 		return nil
 	})
 
+	displayVersion := flag.Bool("version", false, "Display version and exit")
+
 	flag.Parse()
 
+	if *displayVersion {
+		fmt.Printf("Version:\t%s\n", version)
+		fmt.Printf("Build time:\t%s\n", buildTime)
+		os.Exit(0)
+	}
+
 	logger := jsonlog.New(os.Stdout, jsonlog.LevelInfo)
 
 	log.Printf("%s\n", cfg.db.dsn)
@@ -114,6 +126,20 @@ func main() {
 	}
 	
 	defer db.Close()
+
+	expvar.NewString("version").Set(version)
+
+	expvar.Publish("goroutines", expvar.Func(func() interface{} {
+		return runtime.NumGoroutine()
+	}))
+
+	expvar.Publish("database", expvar.Func(func() interface{} {
+		return db.Stats()
+	}))
+
+	expvar.Publish("timestamp", expvar.Func(func() interface{} {
+		return time.Now().Unix()
+	}))
 	
 	app := &application{
 		config: cfg,

cmd/api/middleware.go

@@ -8,6 +8,10 @@ import (
 	"time"
 	"strings"
 	"errors"
+	"expvar"
+	"strconv"
+
+	"github.com/felixge/httpsnoop"
 
 	"golang.org/x/time/rate"
 	"party.at/party/internal/data"
@@ -213,3 +217,64 @@ func (app *application) requirePermission(code string, next http.HandlerFunc) ht
 	// Wrap this with the requireActivatedUser() middleware before returning it.
 	return app.requireActivatedUser(fn)
 }
+
+func (app *application) enableCORS(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Add("Vary", "Origin")
+
+		w.Header().Add("Vary", "Access-Control-Request-Method")
+
+		origin := r.Header.Get("Origin")
+
+		if origin != "" && len(app.config.cors.trustedOrigins) != 0 {
+			// Loop through the list of trusted origins, checking to see if the request
+			// origin exactly matches one of them.
+			for i := range app.config.cors.trustedOrigins {
+				if origin == app.config.cors.trustedOrigins[i] {
+					// If there is a match, then set a "Access-Control-Allow-Origin"
+					// response header with the request origin as the value.
+					w.Header().Set("Access-Control-Allow-Origin", origin)
+
+					if r.Method == http.MethodOptions && r.Header.Get("Access-Control-Request-Method") != "" {
+						// Set the necessary preflight response headers, as discussed
+						// previously.
+						w.Header().Set("Access-Control-Allow-Methods", "OPTIONS, PUT, PATCH, DELETE")
+						w.Header().Set("Access-Control-Allow-Headers","Authorization, Content-Type")
+
+						// Write the headers along with a 200 OK status and return from
+						// the middleware with no further action.
+						w.WriteHeader(http.StatusOK)
+						return
+					}
+				}
+			}
+		}
+
+		next.ServeHTTP(w, r)
+	})
+}
+
+func (app *application) metrics(next http.Handler) http.Handler {
+	// Initialize the new expvar variables when the middleware chain is first built.
+	totalRequestsReceived := expvar.NewInt("total_requests_received")
+	totalResponsesSent := expvar.NewInt("total_responses_sent")
+	totalProcessingTimeMicroseconds := expvar.NewInt("total_processing_time_μs")
+
+	totalResponsesSentByStatus := expvar.NewMap("total_responses_sent_by_status")
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+		totalRequestsReceived.Add(1)
+
+		// Call the next handler in the chain.
+		metrics := httpsnoop.CaptureMetrics(next, w, r)
+
+		// On the way back up the middleware chain, increment the number of responses
+		// sent by 1.
+		totalResponsesSent.Add(1)
+
+		totalProcessingTimeMicroseconds.Add(metrics.Duration.Microseconds())
+
+		totalResponsesSentByStatus.Add(strconv.Itoa(metrics.Code), 1)
+	})
+}

cmd/api/routes.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"net/http"
+	"expvar"
 	"github.com/julienschmidt/httprouter"
 )
 
@@ -34,5 +35,7 @@ func (app *application) routes() http.Handler {
 
 	router.HandlerFunc(http.MethodPost, "/v1/tokens/authentication", app.createAuthenticationTokenHandler)
 
-	return app.recoverPanic(app.enableCORS(app.rateLimit(app.authenticate(router))))
+	router.Handler(http.MethodGet, "/debug/vars", expvar.Handler())
+
+	return app.metrics(app.recoverPanic(app.enableCORS(app.rateLimit(app.authenticate(router)))))
 }