Extract useragent package

Fixes #30

api/api.go

@@ -6,13 +6,13 @@ import (
 	"html/template"
 	"io"
 
+	"github.com/mpolden/ipd/useragent"
 	"github.com/sirupsen/logrus"
 
 	"math/big"
 	"net"
 	"net/http"
 	"path/filepath"
-	"regexp"
 	"strconv"
 	"strings"
 
@@ -24,10 +24,6 @@ const (
 	textMediaType = "text/plain"
 )
 
-var userAgentPattern = regexp.MustCompile(
-	`^(?:curl|Wget|fetch\slibfetch|ddclient|Go-http-client|HTTPie)\/.*|Go\s1\.1\spackage\shttp$`,
-)
-
 type API struct {
 	Template string
 	IPHeader string
@@ -210,7 +206,12 @@ func (a *API) NotFoundHandler(w http.ResponseWriter, r *http.Request) *appError
 }
 
 func cliMatcher(r *http.Request, rm *mux.RouteMatch) bool {
-	return userAgentPattern.MatchString(r.UserAgent())
+	ua := useragent.Parse(r.UserAgent())
+	switch ua.Product {
+	case "curl", "HTTPie", "Wget", "fetch libfetch", "Go", "Go-http-client", "ddclient":
+		return true
+	}
+	return false
 }
 
 type appHandler func(http.ResponseWriter, *http.Request) *appError

api/api_test.go

@@ -150,6 +150,7 @@ func TestCLIMatcher(t *testing.T) {
 	}{
 		{"curl/7.26.0", true},
 		{"Wget/1.13.4 (linux-gnu)", true},
+		{"Wget", true},
 		{"fetch libfetch/2.0", true},
 		{"HTTPie/0.9.3", true},
 		{"Go 1.1 package http", true},