Improve login redirect (#959)

@mieciu please test it before merging. I could not do that locally.

It fixes two issues:
- right redirect if you host it on different domain than localhost
- do also redirect if HTMX hit it in some fragment (auto-refreshed
panel)

---------

Co-authored-by: przemyslaw <[email protected]>

quesma/quesma/ui/console_routes.go

@@ -23,6 +23,7 @@ const (
 	uiTcpPort              = "9999"
 	managementInternalPath = "/_quesma"
 	healthPath             = managementInternalPath + "/health"
+	loginWithElasticSearch = "/login-with-elasticsearch"
 )
 
 //go:embed asset/*
@@ -70,7 +71,7 @@ func (qmc *QuesmaManagementConsole) createRouting() *mux.Router {
 	router.HandleFunc("/auth/{provider}/callback", authCallbackHandler)
 
 	// our logic for login
-	router.HandleFunc("/login-with-elasticsearch", qmc.HandleElasticsearchLogin)
+	router.HandleFunc(loginWithElasticSearch, qmc.HandleElasticsearchLogin)
 
 	authenticatedRoutes := router.PathPrefix("/").Subrouter()
 	if qmc.cfg.Elasticsearch.User == "" && qmc.cfg.Elasticsearch.Password == "" {

quesma/quesma/ui/es_auth_provider.go

@@ -25,7 +25,7 @@ func NewElasticsearchAuthProvider() *ElasticsearchAuthProvider {
 type ElasticsearchSession struct{}
 
 func (e ElasticsearchSession) GetAuthURL() (string, error) {
-	return "http://localhost:9999/login-with-elasticsearch", nil
+	return loginWithElasticSearch, nil
 }
 
 func (e ElasticsearchSession) Marshal() string {

quesma/quesma/ui/html_utils.go

@@ -85,8 +85,6 @@ func (qmc *QuesmaManagementConsole) generateTopNavigation(target string) []byte
 	buffer.Html(abTestingPath)
 	buffer.Html(`">A/B</a></li>`)
 
-	buffer.Html(`<li><a href="/logout">Logout</a></li>`)
-
 	if qmc.isAuthEnabled {
 		buffer.Html(`<li><a href="/logout">Logout</a></li>`)
 	}

quesma/quesma/ui/login.go

@@ -20,7 +20,7 @@ func (qmc *QuesmaManagementConsole) generateLoginForm() []byte {
 	buffer.Html(`<div class="login-form">`)
 	buffer.Html(`<h2>Login</h2>`)
 	buffer.Html(`<p style="color: #ccc;">Log in to Quesma admin console using your Elasticsearch credentials</p>`)
-	buffer.Html(`<form action="/login-with-elasticsearch" method="post">`)
+	buffer.Html(`<form action="`).Text(loginWithElasticSearch).Html(`" method="post">`)
 	buffer.Html(`<label for="username">Username:</label>`)
 	buffer.Html(`<input type="text" id="username" name="username" placeholder="Enter your Elasticsearch username" autofocus>`)
 	buffer.Html(`<label for="password">Password:</label>`)
@@ -41,6 +41,7 @@ func (qmc *QuesmaManagementConsole) HandleElasticsearchLogin(writer http.Respons
 			return
 		}
 		writer.Header().Set("Content-Type", "text/html")
+		writer.Header().Set("HX-Redirect", loginWithElasticSearch)
 		writer.Write(qmc.generateLoginForm())
 	} else if req.Method == http.MethodPost {
 		username := req.FormValue("username")