fix: Fixed server install scripts

server/cmd/main.go

@@ -19,6 +19,13 @@ func main() {
 	mongoURI := getEnv("MONGO_URI", "mongodb://localhost:27017")
 	dbName := getEnv("MONGO_DB", "vantage")
 
+	// Agents dial gRPC directly, so there is no sane default: falling back to the
+	// public web host would hand every new agent a config pointing at a port that
+	// does not speak gRPC. Fail loudly at boot instead of at install time.
+	if os.Getenv("GRPC_HOST") == "" {
+		log.Fatal("GRPC_HOST is required (host:port agents dial for gRPC)")
+	}
+
 	if err := db.Connect(mongoURI, dbName); err != nil {
 		log.Fatalf("failed to connect to MongoDB: %v", err)
 	}

server/internal/api/handlers.go

@@ -137,10 +137,8 @@ func newServer(c *gin.Context) {
 	if giteaHost == "" {
 		giteaHost = "gitea.example.com"
 	}
-	host := os.Getenv("PUBLIC_HOST")
-	if host == "" {
-		host = "https://vantage.example.com"
-	}
+
+	host := publicHostFromRequest(c)
 
 	installCmd := fmt.Sprintf(
 		`curl -fsSL "%s/install?server_id=%s&token=%s" | bash`,
@@ -494,14 +492,7 @@ func handleInstallScript(c *gin.Context) {
 	if giteaHost == "" {
 		giteaHost = "gitea.example.com"
 	}
-	publicHost := os.Getenv("PUBLIC_HOST")
-	if publicHost == "" {
-		publicHost = "vantage.example.com"
-	}
 	grpcHost := os.Getenv("GRPC_HOST")
-	if grpcHost == "" {
-		grpcHost = publicHost
-	}
 
 	script := fmt.Sprintf(`#!/usr/bin/env bash
 set -euo pipefail
@@ -509,9 +500,6 @@ set -euo pipefail
 SERVER_ID="%s"
 TOKEN="%s"
 GITEA_HOST="%s"
-KM_HOST="%s"
-KM_HOST="${KM_HOST#https://}"
-KM_HOST="${KM_HOST#http://}"
 GRPC_HOST="%s"
 GRPC_HOST="${GRPC_HOST#https://}"
 GRPC_HOST="${GRPC_HOST#http://}"
@@ -584,7 +572,7 @@ systemctl daemon-reload
 systemctl enable --now vantage-agent
 
 echo "vantage-agent installed and started."
-`, serverID, token, giteaHost, publicHost, grpcHost)
+`, serverID, token, giteaHost, grpcHost)
 
 	c.Header("Content-Type", "text/x-shellscript")
 	c.String(http.StatusOK, script)

server/internal/api/install_ps1.go

@@ -16,13 +16,8 @@ func handleInstallScriptWindows(c *gin.Context) {
 	if giteaHost == "" {
 		giteaHost = "gitea.example.com"
 	}
+	// Guaranteed non-empty: main() fatals at boot if GRPC_HOST is unset.
 	grpcHost := os.Getenv("GRPC_HOST")
-	if grpcHost == "" {
-		grpcHost = os.Getenv("PUBLIC_HOST")
-	}
-	if grpcHost == "" {
-		grpcHost = "vantage.example.com"
-	}
 
 	script := fmt.Sprintf(
 		"#Requires -RunAsAdministrator\n"+

server/internal/api/publichost.go

@@ -0,0 +1,51 @@
+package api
+
+import (
+	"net"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+)
+
+func publicHostFromRequest(c *gin.Context) string {
+	host := c.Request.Host
+	if h := firstForwarded(c.GetHeader("X-Forwarded-Host")); h != "" {
+		host = h
+	}
+	if host == "" {
+		return "https://vantage.example.com"
+	}
+	return schemeFor(c, host) + "://" + host
+}
+
+func schemeFor(c *gin.Context, host string) string {
+	if p := firstForwarded(c.GetHeader("X-Forwarded-Proto")); p != "" {
+		return p
+	}
+	if c.Request.TLS != nil {
+		return "https"
+	}
+	if isLoopback(host) {
+		return "http"
+	}
+	return "https"
+}
+
+func firstForwarded(v string) string {
+	if v == "" {
+		return ""
+	}
+	return strings.TrimSpace(strings.Split(v, ",")[0])
+}
+
+func isLoopback(host string) bool {
+	h, _, err := net.SplitHostPort(host)
+	if err != nil {
+		h = host
+	}
+	if h == "localhost" || strings.HasSuffix(h, ".localhost") {
+		return true
+	}
+	ip := net.ParseIP(h)
+	return ip != nil && ip.IsLoopback()
+}