Simplify the http handler by using global options

go.sum

@@ -85,6 +85,7 @@ github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869/go.mod h1:Ekp36dR
 github.com/boombuler/barcode v1.0.1-0.20190219062509-6c824513bacc/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
 github.com/bradfitz/gomemcache v0.0.0-20220106215444-fb4bf637b56d/go.mod h1:H0wQNHz2YrLsuXOZozoeDmnHXkNCRmMW0gwFWDfEZDA=
 github.com/casbin/casbin/v2 v2.1.2/go.mod h1:YcPU1XXisHhLzuxH9coDNf2FbKpjGlbCg3n9yuLkIJQ=
+github.com/cenkalti/backoff v2.2.1+incompatible h1:tNowT99t7UNflLxfYYSlKYsBpXdEet03Pg2g16Swow4=
 github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/cenkalti/backoff/v4 v4.0.2/go.mod h1:eEew/i+1Q6OrCDZh3WiXYv3+nJwBASZ8Bog/87DQnVg=
 github.com/cenkalti/backoff/v4 v4.1.0/go.mod h1:scbssz8iZGpm3xbr14ovlUdkxfGXNInqkPWOWmG2CLw=

main.go

@@ -11,21 +11,18 @@ import (
 	"git.autistici.org/id/auth/client"
 )
 
-const defaultPort = 4041
+var (
+	port    = flag.Int("port", 4041, "A port to bind to on the specified addresses")
+	service = flag.String("service", "xmpp", "Service to use for authentication")
+)
 
 func main() {
-	var port = flag.Int("port", defaultPort, "A port to bind to on the specified addresses")
 	flag.Parse()
 
-	if flag.NArg() != 1 {
-		log.Fatal("Expected exactly one service name")
-	}
-
-	service := flag.Args()[0]
-
+	http.HandleFunc("/", authHandlerFunc)
 	log.Fatal(http.ListenAndServe(
 		fmt.Sprintf("127.0.0.1:%d", *port),
-		http.HandlerFunc(authHandlerFunc(service))))
+		nil))
 }
 
 type authPayload struct {
@@ -33,8 +30,7 @@ type authPayload struct {
 	Pass string `json:"password"`
 }
 
-func authHandlerFunc(service string) func(w http.ResponseWriter, r *http.Request) {
-	return func(w http.ResponseWriter, r *http.Request) {
+func authHandlerFunc(w http.ResponseWriter, r *http.Request) {
 	var p authPayload
 	err := json.NewDecoder(r.Body).Decode(&p)
 	if err != nil {
@@ -45,7 +41,7 @@ func authHandlerFunc(service string) func(w http.ResponseWriter, r *http.Request
 
 	c := client.New(client.DefaultSocketPath)
 	resp, err := c.Authenticate(r.Context(), &auth.Request{
-			Service:  service,
+		Service:  *service,
 		Username: p.User,
 		Password: []byte(p.Pass),
 	})
@@ -66,4 +62,3 @@ func authHandlerFunc(service string) func(w http.ResponseWriter, r *http.Request
 		return
 	}
 }
-}