Make api URL dynamic in web app

pkg/api/api.go

@@ -25,8 +25,7 @@ func New(token string) *API {
 
 func (api *API) EnableCors(fn http.HandlerFunc) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Add("Access-Control-Allow-Origin", "http://localhost:8001") // todo: configurable port
-		w.Header().Add("Access-Control-Allow-Credentials", "true")
+		w.Header().Add("Access-Control-Allow-Origin", "*")
 		w.Header().Add("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, accept, origin, Cache-Control, X-Requested-With")
 		w.Header().Add("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
 

pkg/dashboard/dashboard.go

@@ -1,36 +1,82 @@
 package dashboard
 
 import (
+	"fmt"
+	"html/template"
 	"net/http"
+	"strings"
 
 	log "github.com/sirupsen/logrus"
 )
 
 // Dashboard is the http server responsible for serving the static Dashboard files
 type Dashboard struct {
+	port       string
+	rootDir    string
+	apiPort    string
+	apiScheme  string
+	apiVersion string
 }
 
 // New is a factory function creating a new Dashboard instance
 func New() *Dashboard {
-	return &Dashboard{}
+	const webRootDir = "./web/static" // Todo: needs to work in containerized environment
+	const webPort = "8001"            // Todo: make configurable?
+	const apiPort = "8080"            // Todo: make configurable?
+
+	return &Dashboard{
+		apiPort:    apiPort,
+		apiScheme:  "http",
+		apiVersion: "v1",
+		rootDir:    webRootDir,
+		port:       webPort,
+	}
 }
 
 // Start the Dashboard and serve over HTTP
-func (dashboard *Dashboard) Start() error {
+func (d *Dashboard) Start() error {
 	go func() {
-		runHTTPServer()
+		d.runHTTPServer()
 	}()
 	return nil
 }
 
-func runHTTPServer() {
+func (d *Dashboard) templatedHttpHandler(h http.Handler) http.HandlerFunc {
+	const apiUrlTemplate = "%s://%s:%s/%s/"
+	indexTemplate, err := template.ParseFiles(d.rootDir + "/index.html")
+	if err != nil {
+		log.Error("Error when parsing index template")
+		log.Error(err)
+		return nil
+	}
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/" {
+			hostName := strings.Split(r.Host, ":")[0]
+			apiUrl := fmt.Sprintf(apiUrlTemplate, d.apiScheme, hostName, d.apiPort, d.apiVersion)
+			err = indexTemplate.Execute(w, struct{ ApiUrl string }{
+				ApiUrl: apiUrl,
+			})
+			if err != nil {
+				log.Error("Error when executing index template")
+				log.Error(err)
+				w.WriteHeader(http.StatusInternalServerError)
+				return
+			}
+		} else {
+			h.ServeHTTP(w, r)
+		}
+	}
+}
+
+func (d *Dashboard) getHandler() http.Handler {
+	return d.templatedHttpHandler(http.FileServer(http.Dir(d.rootDir)))
+}
+
+func (d *Dashboard) runHTTPServer() {
 	serveMux := http.NewServeMux()
-	serveMux.Handle("/", getHandler())
+	serveMux.Handle("/", d.getHandler())
 
 	log.Debug("Starting http dashboard server")
-	log.Fatal(http.ListenAndServe(":8001", serveMux))
-}
-
-func getHandler() http.Handler {
-	return http.FileServer(http.Dir("./web/static"))
+	log.Fatal(http.ListenAndServe(":"+d.port, serveMux))
 }

web/static/api.js

@@ -1,6 +1,15 @@
 
+function getEmbeddedVariable(variableName) {
+    const value = document.body.getAttribute(`data-${variableName}`);
+    if (value === null) {
+        throw new Error(`No ${variableName} embedded variable detected`);
+    }
+
+    return value;
+}
+
 const apiFactory = () => {
-    const baseUrl = "http://localhost:8080/v1";
+    const apiBasePath = getEmbeddedVariable("apipath");
     let token = "";
 
     const headers = () => ({
@@ -9,15 +18,15 @@ const apiFactory = () => {
 
     const logIn = async (password, remember) => {
         token = password;
-        const response = await fetch(baseUrl + "/list", {
-            credentials: "include",
+        const response = await fetch(apiBasePath + "list", {
             headers: headers()
         });
 
         if (response.ok) {
             if (remember === true) {
-                localStorage.setItem("token", password);
+                localStorage.setItem("token", token);
             }
+
             return true;
         }
 
@@ -27,11 +36,10 @@ const apiFactory = () => {
 
     const checkLogin = async () => {
         const token = localStorage.getItem("token");
-
         if (token) {
-            const isLoggedIn = await logIn(token);
-            return isLoggedIn;
+            return await logIn(token);
         }
+
         return false;
     };
 
@@ -40,8 +48,7 @@ const apiFactory = () => {
     };
 
     const list = async () => {
-        const response = await fetch(baseUrl + "/list", {
-            credentials: "include",
+        const response = await fetch(apiBasePath + "list", {
             headers: headers()
         });
         const data = await response.json();
@@ -52,9 +59,8 @@ const apiFactory = () => {
         const requestData = {
             ContainerId: containerId
         };
-        const response = await fetch(baseUrl + "/check", {
+        const response = await fetch(apiBasePath + "check", {
             method: "POST",
-            credentials: "include",
             headers: {
                 ...headers(),
                 "Content-Type": "application/json",
@@ -66,14 +72,13 @@ const apiFactory = () => {
     };
 
     const update = async (images) => {
-        let updateUrl = new URL(baseUrl + "/update");
+        let updateUrl = new URL(apiBasePath + "/update");
 
         if (images instanceof Array) {
             images.map(image => updateUrl.searchParams.append("image", image));
         }
 
         const response = await fetch(updateUrl.toString(), {
-            credentials: "include",
             headers: headers(),
         });
 

web/static/index.html

@@ -16,7 +16,7 @@
     <script type="text/javascript" src="lib/react-dom@18.2.0/react-dom.production.min.js"></script>
 </head>
 
-<body>
+<body data-apipath="{{.ApiUrl}}">
     <div id="root"></div>
     <script type="text/javascript" src="api.js?v=1"></script>
     <script type="text/babel" src="app.jsx?v=1"></script>