feat(proxy): Add reverse proxy feature

app/server/gateway.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 
 	"git.secnex.io/secnex/api-gateway/config"
+	"git.secnex.io/secnex/api-gateway/middlewares"
 	"git.secnex.io/secnex/masterlog"
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
@@ -12,22 +13,39 @@ import (
 
 type Gateway struct {
 	router *chi.Mux
-	config config.Config
+	config config.Configuration
+	apis   Apis
 	routes *Routes
-	proxy  *Proxy
 }
 
-func NewGateway(config config.Config) *Gateway {
+func (g *Gateway) configureProxies() {
+	for _, api := range g.apis {
+		masterlog.Info("Configuring proxy", map[string]interface{}{
+			"id":     api.ID,
+			"host":   api.Host.Domain,
+			"target": api.Target.URL.String(),
+		})
+		originalDirector := api.Target.proxy.Director
+		api.Target.proxy.Director = func(r *http.Request) {
+			originalDirector(r)
+			r.Host = api.Host.Domain
+		}
+	}
+}
+
+func NewGateway(cfg *config.Configuration) *Gateway {
 	r := chi.NewRouter()
 
-	for _, feature := range config.GetFeatures() {
+	for _, feature := range cfg.Gateway.Features {
 		switch feature {
 		case "request_id":
 			r.Use(middleware.RequestID)
 		case "real_ip":
 			r.Use(middleware.RealIP)
 		case "logger":
-			r.Use(middleware.Logger)
+			r.Use(middlewares.LoggerMiddleware)
+		case "host":
+			r.Use(middlewares.HostMiddleware)
 		}
 	}
 
@@ -38,30 +56,22 @@ func NewGateway(config config.Config) *Gateway {
 		})
 	})
 
-	return &Gateway{config: config, router: r, routes: nil, proxy: nil}
-}
+	hosts := NewHosts(cfg)
+	targets := NewTargets(cfg)
+	apis := NewApis(cfg, hosts, targets)
+	routes := NewRoutes(cfg, apis)
 
-func (g *Gateway) SetRoutes(routes *Routes) {
-	g.routes = routes
-}
-
-func (g *Gateway) SetProxy(proxy *Proxy) {
-	g.proxy = proxy
+	return &Gateway{config: *cfg, router: r, apis: apis, routes: routes}
 }
 
 func (g *Gateway) Start() {
 	masterlog.Info("Starting gateway", map[string]interface{}{
-		"host": g.config.GetGatewayConfiguration().Host,
-		"port": g.config.GetGatewayConfiguration().Port,
+		"host": g.config.Gateway.Host,
+		"port": g.config.Gateway.Port,
 	})
-	for path, handler := range g.routes.handlers {
-		masterlog.Info("Registering route", map[string]interface{}{
-			"path": path,
-		})
-		g.router.Handle(path, handler)
-	}
 
-	gatewayConfig := g.config.GetGatewayConfiguration()
+	g.configureProxies()
+	g.routes.Register(g.router)
 
-	http.ListenAndServe(fmt.Sprintf("%s:%d", gatewayConfig.Host, gatewayConfig.Port), g.router)
+	http.ListenAndServe(fmt.Sprintf("%s:%d", g.config.Gateway.Host, g.config.Gateway.Port), g.router)
 }