Add dashboard to steve

pkg/dashboard/ui.go

@@ -0,0 +1,90 @@
+package dashboard
+
+import (
+	"crypto/tls"
+	"io"
+	"net/http"
+	"strings"
+
+	"github.com/gorilla/mux"
+	"github.com/rancher/steve/pkg/responsewriter"
+	"github.com/rancher/steve/pkg/schemaserver/parse"
+	"github.com/sirupsen/logrus"
+)
+
+var (
+	insecureClient = &http.Client{
+		Transport: &http.Transport{
+			Proxy: http.ProxyFromEnvironment,
+			TLSClientConfig: &tls.Config{
+				InsecureSkipVerify: true,
+			},
+		},
+	}
+)
+
+func content(uiSetting func() string) http.Handler {
+	return http.FileServer(http.Dir(uiSetting()))
+}
+
+func Route(next http.Handler, uiSetting func() string) http.Handler {
+	uiContent := responsewriter.NewMiddlewareChain(responsewriter.Gzip,
+		responsewriter.DenyFrameOptions,
+		responsewriter.CacheMiddleware("json", "js", "css")).Handler(content(uiSetting))
+
+	root := mux.NewRouter()
+	root.Path("/dashboard").HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+		rw.Header().Add("Location", "/dashboard/")
+		rw.WriteHeader(http.StatusFound)
+	})
+	root.PathPrefix("/dashboard/assets").Handler(uiContent)
+	root.PathPrefix("/dashboard/translations").Handler(uiContent)
+	root.PathPrefix("/dashboard/engines-dist").Handler(uiContent)
+	root.Handle("/dashboard/asset-manifest.json", uiContent)
+	root.Handle("/dashboard/index.html", uiContent)
+	root.PathPrefix("/dashboard/").Handler(wrapUI(next, uiSetting))
+	root.NotFoundHandler = next
+
+	return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+		if strings.HasPrefix(req.URL.Path, "/k8s/clusters/local") {
+			req.URL.Path = strings.TrimPrefix(req.URL.Path, "/k8s/clusters/local")
+			if req.URL.Path == "" {
+				req.URL.Path = "/"
+			}
+		}
+		root.ServeHTTP(rw, req)
+	})
+}
+
+func wrapUI(next http.Handler, uiGetter func() string) http.Handler {
+	return http.HandlerFunc(func(resp http.ResponseWriter, req *http.Request) {
+		if parse.IsBrowser(req, true) {
+			path := uiGetter()
+			if strings.HasPrefix(path, "http") {
+				ui(resp, req, path)
+			} else {
+				http.ServeFile(resp, req, path)
+			}
+		} else {
+			next.ServeHTTP(resp, req)
+		}
+	})
+}
+
+func ui(resp http.ResponseWriter, req *http.Request, url string) {
+	if err := serveIndex(resp, req, url); err != nil {
+		logrus.Errorf("failed to serve UI: %v", err)
+		resp.WriteHeader(500)
+	}
+}
+
+func serveIndex(resp http.ResponseWriter, req *http.Request, url string) error {
+	r, err := insecureClient.Get(url)
+	if err != nil {
+		return err
+	}
+	defer r.Body.Close()
+
+	_, err = io.Copy(resp, r.Body)
+	return err
+}