V2 alpha - initial version (#172)

Initial alpha codebase for version 2 of WireGuard Portal.
This version is considered unstable and incomplete (for example, no public REST API)! 
Use with care!


Fixes/Implements the following issues:
 - OAuth support #154, #1 
 - New Web UI with internationalisation support #98, #107, #89, #62
 - Postgres Support #49 
 - Improved Email handling #47, #119 
 - DNS Search Domain support #46 
 - Bugfixes #94, #48 

---------

Co-authored-by: Fabian Wechselberger <wechselbergerf@hotmail.com>

internal/app/api/v0/handlers/endpoint_config.go

@@ -0,0 +1,101 @@
+package handlers
+
+import (
+	"bytes"
+	"embed"
+	"fmt"
+	"github.com/gin-gonic/gin"
+	"github.com/h44z/wg-portal/internal/app"
+	"github.com/h44z/wg-portal/internal/app/api/v0/model"
+	"html/template"
+	"net"
+	"net/http"
+	"net/url"
+)
+
+//go:embed frontend_config.js.gotpl
+var frontendJs embed.FS
+
+type configEndpoint struct {
+	app           *app.App
+	authenticator *authenticationHandler
+
+	tpl *template.Template
+}
+
+func newConfigEndpoint(app *app.App, authenticator *authenticationHandler) configEndpoint {
+	ep := configEndpoint{
+		app:           app,
+		authenticator: authenticator,
+		tpl:           template.Must(template.ParseFS(frontendJs, "frontend_config.js.gotpl")),
+	}
+
+	return ep
+}
+
+func (e configEndpoint) GetName() string {
+	return "ConfigEndpoint"
+}
+
+func (e configEndpoint) RegisterRoutes(g *gin.RouterGroup, authenticator *authenticationHandler) {
+	apiGroup := g.Group("/config")
+
+	apiGroup.GET("/frontend.js", e.handleConfigJsGet())
+	apiGroup.GET("/settings", e.authenticator.LoggedIn(), e.handleSettingsGet())
+}
+
+// handleConfigJsGet returns a gorm handler function.
+//
+// @ID config_handleConfigJsGet
+// @Tags Configuration
+// @Summary Get the dynamic frontend configuration javascript.
+// @Produce text/javascript
+// @Success 200 string javascript "The JavaScript contents"
+// @Router /config/frontend.js [get]
+func (e configEndpoint) handleConfigJsGet() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		backendUrl := fmt.Sprintf("%s/api/v0", e.app.Config.Web.ExternalUrl)
+		if c.GetHeader("x-wg-dev") != "" {
+			referer := c.Request.Header.Get("Referer")
+			host := "localhost"
+			port := "5000"
+			parsedReferer, err := url.Parse(referer)
+			if err == nil {
+				host, port, _ = net.SplitHostPort(parsedReferer.Host)
+			}
+			backendUrl = fmt.Sprintf("http://%s:%s/api/v0", host, port) // override if request comes from frontend started with npm run dev
+		}
+		buf := &bytes.Buffer{}
+		err := e.tpl.ExecuteTemplate(buf, "frontend_config.js.gotpl", gin.H{
+			"BackendUrl":      backendUrl,
+			"Version":         "unknown",
+			"SiteTitle":       e.app.Config.Web.SiteTitle,
+			"SiteCompanyName": e.app.Config.Web.SiteCompanyName,
+		})
+		if err != nil {
+			c.Status(http.StatusInternalServerError)
+			return
+		}
+
+		c.Data(http.StatusOK, "application/javascript", buf.Bytes())
+	}
+}
+
+// handleSettingsGet returns a gorm handler function.
+//
+// @ID config_handleSettingsGet
+// @Tags Configuration
+// @Summary Get the frontend settings object.
+// @Produce json
+// @Success 200 {object} model.Settings
+// @Success 200 string javascript "The JavaScript contents"
+// @Router /config/settings [get]
+func (e configEndpoint) handleSettingsGet() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		c.JSON(http.StatusOK, model.Settings{
+			MailLinkOnly:              e.app.Config.Mail.LinkOnly,
+			PersistentConfigSupported: e.app.Config.Advanced.ConfigStoragePath != "",
+			SelfProvisioning:          e.app.Config.Core.SelfProvisioningAllowed,
+		})
+	}
+}