fix proxy race conditions

models/docker.go

@@ -2,6 +2,7 @@ package models
 
 type Containers struct {
 	ID           string `json:"id"`
+	Head         bool   `json:"head"` // if the container is the head of the deployment
 	ContainerID  string `json:"container_id"`
 	DeploymentID int64  `json:"deployment_id"`
 	CreatedAt    string `json:"created_at"`

server/deployment.go

@@ -23,7 +23,7 @@ func (s *FluxServer) CreateDeployment(ctx context.Context, projectConfig models.
 		return 0, err
 	}
 
-	_, err = s.db.Exec("INSERT INTO containers (container_id, deployment_id) VALUES (?, ?)", containerID, deploymentID)
+	_, err = s.db.Exec("INSERT INTO containers (container_id, deployment_id, head) VALUES (?, ?, ?)", containerID, deploymentID, true)
 	if err != nil {
 		log.Printf("Failed to get container id: %v\n", err)
 		return 0, err
@@ -65,7 +65,10 @@ func (s *FluxServer) UpgradeDeployment(ctx context.Context, deploymentID int64,
 		return err
 	}
 
-	s.db.Exec("INSERT INTO containers (container_id, deployment_id) VALUES (?, ?)", containerID, deploymentID)
+	if _, err := s.db.Exec("INSERT INTO containers (container_id, deployment_id, head) VALUES (?, ?, ?)", containerID, deploymentID, true); err != nil {
+		log.Printf("Failed to insert container: %v\n", err)
+		return err
+	}
 
 	// update app in the database
 	if _, err := s.db.Exec("UPDATE apps SET project_config = ?, deployment_id = ? WHERE name = ?", configBytes, deploymentID, projectConfig.Name); err != nil {

server/proxy.go

@@ -3,7 +3,6 @@ package server
 import (
 	"context"
 	"database/sql"
-	"encoding/json"
 	"fmt"
 	"log"
 	"net/http"
@@ -18,13 +17,16 @@ import (
 )
 
 type ContainerProxy struct {
-	mu          sync.RWMutex
+	routes      *RouteCache
-	urlMap      map[string]*containerRoute
 	db          *sql.DB
 	cm          *ContainerManager
 	activeConns int64
 }
 
+type RouteCache struct {
+	m sync.Map
+}
+
 type containerRoute struct {
 	containerID string
 	port        int
@@ -33,107 +35,49 @@ type containerRoute struct {
 	isActive    bool
 }
 
-func (cp *ContainerProxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+func (rc *RouteCache) GetRoute(appUrl string) *containerRoute {
-	cp.mu.RLock()
-	// defer cp.mu.RUnlock()
 
+	container, exists := rc.m.Load(appUrl)
+	if !exists {
+		return nil
+	}
+
+	return container.(*containerRoute)
+}
+
+func (rc *RouteCache) SetRoute(appUrl string, container *containerRoute) {
+	rc.m.Store(appUrl, container)
+}
+
+func (rc *RouteCache) DeleteRoute(appUrl string) {
+	rc.m.Delete(appUrl)
+}
+
+func (cp *ContainerProxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	// Extract app name from host
 	appUrl := r.Host
-	var container *containerRoute
+
-	container, exists := cp.urlMap[appUrl]
+	container := cp.routes.GetRoute(appUrl)
-	if !exists || !container.isActive {
+	if container == nil {
-		container = &containerRoute{
-			url: appUrl,
-		}
-		var deploymentID int64
-		cp.db.QueryRow("SELECT id FROM deployments WHERE url = ?", appUrl).Scan(&deploymentID)
-		if deploymentID == 0 {
-			fmt.Printf("No deployment found for url: %s\n", appUrl)
 		http.Error(w, "Container not found", http.StatusNotFound)
 		return
 	}
 
-		cp.db.QueryRow("SELECT container_id FROM containers WHERE deployment_id = ?", deploymentID).Scan(&container.containerID)
-		if container.containerID == "" {
-			fmt.Printf("No container found for deployment: %d\n", deploymentID)
-			http.Error(w, "Container not found", http.StatusNotFound)
-			return
-		}
-
-		var projectConfigStr string
-		if err := cp.db.QueryRow("SELECT project_config FROM apps WHERE deployment_id = ?", deploymentID).Scan(&projectConfigStr); err != nil || projectConfigStr == "" {
-			http.Error(w, "Container not found", http.StatusNotFound)
-			return
-		}
-		var projectConfig models.ProjectConfig
-		if err := json.Unmarshal([]byte(projectConfigStr), &projectConfig); err != nil {
-			http.Error(w, "Failed to parse json", http.StatusNotFound)
-			return
-		}
-		container.port = projectConfig.Port
-
-		// cp.urlMap[appUrl] = container
-	}
-
-	if container.proxy == nil {
-		containerJSON, err := cp.cm.dockerClient.ContainerInspect(r.Context(), container.containerID)
-		if err != nil {
-			log.Printf("Failed to inspect container: %v\n", err)
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-
-		if containerJSON.State.Status != "running" {
-			log.Printf("Container %s is not running\n", container.containerID)
-			http.Error(w, "Container not running", http.StatusInternalServerError)
-			return
-		}
-
-		url, err := url.Parse(fmt.Sprintf("http://%s:%d", containerJSON.NetworkSettings.IPAddress, container.port))
-		if err != nil {
-			log.Printf("Failed to parse URL: %v\n", err)
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-		// container.proxy = httputil.NewSingleHostReverseProxy(url)
-		container.proxy = cp.createProxy(url)
-		if container.proxy == nil {
-			log.Printf("Failed to create proxy for container %s\n", container.containerID)
-			http.Error(w, "Failed to create proxy", http.StatusInternalServerError)
-			container.isActive = false
-			return
-		}
-
-		cp.mu.RUnlock()
-		cp.mu.Lock()
-		cp.urlMap[appUrl] = container
-		cp.mu.Unlock()
-	} else {
-		cp.mu.RUnlock()
-	}
-
 	container.proxy.ServeHTTP(w, r)
 }
 
 func (cp *ContainerProxy) AddContainer(projectConfig models.ProjectConfig, containerID string) error {
-	cp.mu.Lock()
-	defer cp.mu.Unlock()
-
 	containerJSON, err := cp.cm.dockerClient.ContainerInspect(context.Background(), containerID)
 	if err != nil {
 		log.Printf("Failed to inspect container: %v\n", err)
 		return err
 	}
+
 	containerUrl, err := url.Parse(fmt.Sprintf("http://%s:%d", containerJSON.NetworkSettings.IPAddress, projectConfig.Port))
 	if err != nil {
+		log.Printf("Failed to parse URL: %v\n", err)
 		return err
 	}
-
-	container, ok := cp.urlMap[projectConfig.Url]
-	if ok && container.proxy != nil {
-		container.isActive = true
-		return nil
-	}
 	proxy := cp.createProxy(containerUrl)
 
 	newRoute := &containerRoute{
@@ -143,7 +87,7 @@ func (cp *ContainerProxy) AddContainer(projectConfig models.ProjectConfig, conta
 		isActive: true,
 	}
 
-	cp.urlMap[projectConfig.Url] = newRoute
+	cp.routes.SetRoute(projectConfig.Url, newRoute)
 	return nil
 }
 
@@ -153,6 +97,13 @@ func (cp *ContainerProxy) createProxy(url *url.URL) *httputil.ReverseProxy {
 	originalDirector := proxy.Director
 	proxy.Director = func(req *http.Request) {
 		atomic.AddInt64(&cp.activeConns, 1)
+
+		// Validate URL before directing
+		if url == nil {
+			log.Printf("URL is nil")
+			return
+		}
+
 		originalDirector(req)
 	}
 
@@ -163,18 +114,20 @@ func (cp *ContainerProxy) createProxy(url *url.URL) *httputil.ReverseProxy {
 
 	// Handle errors
 	proxy.ErrorHandler = func(w http.ResponseWriter, r *http.Request, err error) {
-		log.Printf("Proxy error: %v", err)
+		atomic.AddInt64(&cp.activeConns, -1)
+
 		http.Error(w, "Service unavailable", http.StatusServiceUnavailable)
+
+		// Ensure request body is closed
+		if r.Body != nil {
 			r.Body.Close()
 		}
+	}
 
 	return proxy
 }
 
 func (cp *ContainerProxy) RemoveContainer(containerID string) error {
-	cp.mu.Lock()
-	defer cp.mu.Unlock()
-
 	var deploymentID int64
 	if err := cp.db.QueryRow("SELECT deployment_id FROM containers WHERE id = ?", containerID).Scan(&deploymentID); err != nil {
 		return err
@@ -185,8 +138,8 @@ func (cp *ContainerProxy) RemoveContainer(containerID string) error {
 		return err
 	}
 
-	container, exists := cp.urlMap[url]
+	container := cp.routes.GetRoute(url)
-	if !exists {
+	if container == nil {
 		return fmt.Errorf("container not found")
 	}
 
@@ -198,19 +151,57 @@ func (cp *ContainerProxy) RemoveContainer(containerID string) error {
 	for {
 		select {
 		case <-ctx.Done():
-			delete(cp.urlMap, url)
+			cp.routes.DeleteRoute(url)
 			return nil
 		default:
 			if atomic.LoadInt64(&cp.activeConns) == 0 {
-				delete(cp.urlMap, url)
+				cp.routes.DeleteRoute(url)
 				return nil
 			}
-			time.Sleep(100 * time.Millisecond)
+		}
+	}
+}
+
+func (cp *ContainerProxy) ScanRoutes() {
+	rows, err := cp.db.Query("SELECT url, id FROM deployments")
+	if err != nil {
+		log.Printf("Failed to query deployments: %v\n", err)
+		return
+	}
+	defer rows.Close()
+
+	var containers []models.Containers
+	for rows.Next() {
+		var url string
+		var deploymentID int64
+		if err := rows.Scan(&url, &deploymentID); err != nil {
+			log.Printf("Failed to scan deployment: %v\n", err)
+			return
+		}
+
+		rows, err := cp.db.Query("SELECT * FROM containers WHERE deployment_id = ?", deploymentID)
+		if err != nil {
+			log.Printf("Failed to query containers: %v\n", err)
+			return
+		}
+		defer rows.Close()
+
+		for rows.Next() {
+			var container models.Containers
+			if err := rows.Scan(&container.ID, &container.ContainerID, &container.Head, &container.DeploymentID, &container.CreatedAt); err != nil {
+				log.Printf("Failed to scan container: %v\n", err)
+				return
+			}
+
+			fmt.Printf("Found container: %s\n", container.ContainerID)
+
+			containers = append(containers, container)
 		}
 	}
 }
 
 func (cp *ContainerProxy) Start() {
+	cp.ScanRoutes()
 	port := os.Getenv("FLUXD_PROXY_PORT")
 	if port == "" {
 		port = "7465"

server/schema.sql

@@ -12,6 +12,7 @@ CREATE TABLE IF NOT EXISTS apps (
 CREATE TABLE IF NOT EXISTS containers (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
     container_id TEXT NOT NULL,
+    head BOOLEAN NOT NULL,
     deployment_id INTEGER NOT NULL,
     created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
     FOREIGN KEY(deployment_id) REFERENCES deployments(id)

server/server.go

@@ -105,7 +105,7 @@ func NewServer() *FluxServer {
 		config:           serverConfig,
 		db:               db,
 		Proxy: &ContainerProxy{
-			urlMap: make(map[string]*containerRoute),
+			routes: &RouteCache{},
 			db:     db,
 			cm:     containerManager,
 		},