Use go-http-middleware

go.mod

@@ -3,6 +3,7 @@ module osgrid-server
 go 1.15
 
 require (
+	github.com/paulcager/go-http-middleware v0.0.0-20201217214326-f1e1271eaabe
 	github.com/paulcager/osgridref v1.0.1
 	github.com/spf13/pflag v1.0.5
 )

go.sum

@@ -1,12 +1,21 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/paulcager/go-http-middleware v0.0.0-20201217214326-f1e1271eaabe h1:fA+EZAArUBNnCYx0/5Ct/Rq4lKDmVTzxllz8qccHXFI=
+github.com/paulcager/go-http-middleware v0.0.0-20201217214326-f1e1271eaabe/go.mod h1:K4zISwO5aHZ0dwjY2h0KWB939Rg/ncdkcdTZjze4cFU=
 github.com/paulcager/osgridref v1.0.1 h1:/EX0qWi5LU9zjqE6bxIDgXSEJOAJRCqRIXAnZOB3JnI=
 github.com/paulcager/osgridref v1.0.1/go.mod h1:ufyaMOUx5kOvX4naQZy2JxXME4RnN0y7lec+eIaAt2E=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/robertkrimen/otto v0.0.0-20200922221731-ef014fd054ac h1:kYPjbEN6YPYWWHI6ky1J813KzIq/8+Wg4TO4xU7A/KU=
 github.com/robertkrimen/otto v0.0.0-20200922221731-ef014fd054ac/go.mod h1:xvqspoSXJTIpemEonrMDFq6XzwHYYgToXWj5eRX1OtY=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
 github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/sourcemap.v1 v1.0.5 h1:inv58fC9f9J3TK2Y2R1NPntXEn3/wjWHkonhIUODNTI=
 gopkg.in/sourcemap.v1 v1.0.5/go.mod h1:2RlvNNSMglmRrcvhfuzp4hQHwOtjxlbjX7UPY/GXb78=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

osgrid-server.go

@@ -4,11 +4,11 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
-	"math"
 	"net/http"
 	"strings"
 	"time"
 
+	"github.com/paulcager/go-http-middleware"
 	"github.com/paulcager/osgridref"
 	flag "github.com/spf13/pflag"
 )
@@ -40,7 +40,7 @@ type Reply struct {
 }
 
 func makeHTTPServer(listenPort string) *http.Server {
-	http.Handle("/"+apiVersion+"/gridref/", makeCachingHandler(1*time.Hour, http.HandlerFunc(
+	http.Handle("/"+apiVersion+"/gridref/", middleware.MakeCachingHandler(1*time.Hour, http.HandlerFunc(
 		func(w http.ResponseWriter, r *http.Request) {
 			gridRefStr := r.URL.Path[len("/"+apiVersion+"/gridref/"):]
 			gridRef, err := osgridref.ParseOsGridRef(gridRefStr)
@@ -53,7 +53,7 @@ func makeHTTPServer(listenPort string) *http.Server {
 			handle(w, r, gridRef, lat, lon)
 		})))
 
-	http.Handle("/"+apiVersion+"/latlon/", makeCachingHandler(1*time.Hour, http.HandlerFunc(
+	http.Handle("/"+apiVersion+"/latlon/", middleware.MakeCachingHandler(1*time.Hour, http.HandlerFunc(
 		func(w http.ResponseWriter, r *http.Request) {
 			latLonStr := r.URL.Path[len("/"+apiVersion+"/latlon/"):]
 			latLon, err := osgridref.ParseLatLon(latLonStr, 0, osgridref.WGS84)
@@ -75,7 +75,7 @@ func makeHTTPServer(listenPort string) *http.Server {
 		ReadHeaderTimeout: 20 * time.Second,
 		WriteTimeout:      2 * time.Minute,
 		IdleTimeout:       10 * time.Minute,
-		Handler:           makeLoggingHandler(http.DefaultServeMux),
+		Handler:           middleware.MakeLoggingHandler(http.DefaultServeMux),
 		Addr:              listenPort,
 	}
 
@@ -105,30 +105,3 @@ func handle(w http.ResponseWriter, _ *http.Request, ref osgridref.OsGridRef, lat
 		w.WriteHeader(http.StatusBadGateway)
 	}
 }
-
-func makeCachingHandler(age time.Duration, h http.Handler) http.Handler {
-	ageSeconds := int64(math.Round(age.Seconds()))
-	if ageSeconds <= 0 {
-		return h
-	}
-
-	header := fmt.Sprintf("public,max-age=%d", ageSeconds)
-	return http.HandlerFunc(
-		func(w http.ResponseWriter, r *http.Request) {
-			w.Header().Add("Cache-Control", header)
-			h.ServeHTTP(w, r)
-		})
-}
-
-func makeLoggingHandler(h http.Handler) http.Handler {
-	return http.HandlerFunc(
-		func(w http.ResponseWriter, r *http.Request) {
-			start := time.Now()
-			h.ServeHTTP(w, r)
-			end := time.Now()
-
-			uri := r.URL.String()
-			method := r.Method
-			fmt.Printf("%s %s %s %d\n", method, uri, r.RemoteAddr, end.Sub(start).Milliseconds())
-		})
-}