feat: CA creates a http.ServeMux with its routes (#15)

CA creates a "standard" mux which responds to "POST /issue"
with CA.ServeHTTP.
It also responds to "GET /namespace" with a plain-text UUID
namespace string.

cmd/bf/ca.go

@@ -98,26 +98,19 @@ var caServeCmd = &cli.Command{
 			"notAfter", cert.NotAfter,
 		)
 
-		mux := http.NewServeMux()
-
-		if exposeMetrics {
-			slog.InfoContext(ctx, "metrics enabled")
-			mux.HandleFunc("GET /metrics", webapp.MetricsHandler)
-		}
-
 		ca, err := tinyca.New(cert, key, nil)
 		if err != nil {
 			slog.ErrorContext(ctx, "error creating CA", "error", err)
 			return cli.Exit("Error creating CA", 1)
 		}
 		defer ca.Close()
 
-		mux.Handle("POST /issue", ca)
+		mux := ca.ServeMux()
 
-		nss := cert.Namespace.String()
-		mux.HandleFunc("GET /namespace", func(w http.ResponseWriter, r *http.Request) {
-			fmt.Fprint(w, nss)
-		})
+		if exposeMetrics {
+			slog.InfoContext(ctx, "metrics enabled")
+			mux.HandleFunc("GET /metrics", webapp.MetricsHandler)
+		}
 
 		if webEnabled {
 			slog.InfoContext(ctx, "web interface enabled", "staticPath", webStaticPath)
@@ -127,7 +120,7 @@ var caServeCmd = &cli.Command{
 		hdlr := webapp.RequestLogger(mux)
 
 		addr := fmt.Sprintf("%s:%d", caHost, caPort)
-		slog.InfoContext(ctx, "starting server", "address", addr, "namespace", nss)
+		slog.InfoContext(ctx, "starting server", "address", addr, "namespace", cert.Namespace)
 
 		server := http.Server{Addr: addr, Handler: hdlr}
 

tinyca/ca.go

@@ -174,6 +174,19 @@ func (ca *CA) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// ServeMux returns an http.ServeMux with the CA's HTTP handler registered at "POST /issue".
+// The ServeMux also provides a "GET /namespace" endpoint that returns the namespace of the CA.
+func (ca *CA) ServeMux() *http.ServeMux {
+	mux := http.NewServeMux()
+	mux.Handle("POST /issue", ca)
+	nss := ca.cert.Namespace.String()
+	mux.HandleFunc("GET /namespace", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/plain")
+		fmt.Fprintln(w, nss)
+	})
+	return mux
+}
+
 // IssueCertificate issues a client certificate for a valid certificate request parsed from asn1CSR.
 func (ca *CA) IssueCertificate(asn1CSR []byte, notBefore, notAfter time.Time) ([]byte, error) {
 	issueStart := time.Now()