Cleanup; Adding locks where needed, and checking port availibility

daemon.go

@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"path/filepath"
 	"strconv"
 	"sync"
 	"syscall"
@@ -24,6 +25,7 @@ type InstanceStatusResponse struct {
 }
 
 type DaemonServer struct {
+	sync.RWMutex
 	cfg         *AppConfig
 	configPath  string
 	procManager *ProcessManager
@@ -82,6 +84,19 @@ func StartDaemon(cfg *AppConfig, configPath string) error {
 	return nil
 }
 
+func (ds *DaemonServer) reloadConfig() error {
+	cfg, err := LoadOrCreateConfig(ds.configPath)
+	if err != nil {
+		fmt.Printf("Could not reload configuration file: %v\n", err)
+		return err
+	}
+
+	ds.Lock()
+	defer ds.Unlock()
+	ds.cfg = cfg
+	return nil
+}
+
 func (ds *DaemonServer) shutdownAllRunningServers() {
 	ds.procManager.Lock()
 
@@ -157,11 +172,26 @@ func (ds *DaemonServer) handleCreate(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if ds.reloadConfig() != nil {
+		http.Error(w, "Could not reload config", http.StatusInternalServerError)
+		return
+	}
+
+	ds.Lock()
+	defer ds.Unlock()
+
 	if _, exists := ds.cfg.Instances[name]; exists {
 		http.Error(w, fmt.Sprintf("Instance '%s' already exists in configuration", name), http.StatusConflict)
 		return
 	}
 
+	for name, options := range ds.cfg.Instances {
+		if options.Port == converted_port {
+			http.Error(w, fmt.Sprintf("Port already occupied by instance '%s'", name), http.StatusConflict)
+			return
+		}
+	}
+
 	options := VsServerConfigOptions{
 		Version:    version,
 		ServerName: name,
@@ -199,6 +229,7 @@ func (ds *DaemonServer) handleCreate(w http.ResponseWriter, r *http.Request) {
 }
 
 func (ds *DaemonServer) handleStart(w http.ResponseWriter, r *http.Request) {
+
 	if r.Method != http.MethodPost {
 		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
 		return
@@ -210,13 +241,21 @@ func (ds *DaemonServer) handleStart(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if ds.reloadConfig() != nil {
+		http.Error(w, "Could not reload config", http.StatusInternalServerError)
+		return
+	}
+
+	ds.RLock()
+	defer ds.RUnlock()
+
 	options, exists := ds.cfg.Instances[name]
 	if !exists {
 		http.Error(w, fmt.Sprintf("Instance '%s' does not exist. Run 'create' first", name), http.StatusNotFound)
 		return
 	}
 
-	instanceConfigPath := ds.configPath
+	instanceConfigPath := filepath.Join(ds.cfg.Storage.InstancesDir, name, "serverconfig.json")
 	err := SyncInstanceConfig(options.Version, instanceConfigPath, options, ds.cfg)
 	if err != nil {
 		http.Error(w, "Failed to sync config: "+err.Error(), http.StatusInternalServerError)
@@ -289,6 +328,14 @@ func (ds *DaemonServer) handleList(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if ds.reloadConfig() != nil {
+		http.Error(w, "Could not reload config", http.StatusInternalServerError)
+		return
+	}
+
+	ds.RLock()
+	defer ds.RUnlock()
+
 	ds.procManager.RLock()
 	defer ds.procManager.RUnlock()
 

instance.go

@@ -3,7 +3,6 @@ package main
 import (
 	"fmt"
 	"os"
-	"os/exec"
 	"path/filepath"
 )
 
@@ -14,16 +13,6 @@ const (
 	StateRunning InstanceState = "RUNNING"
 )
 
-type ManagedInstance struct {
-	Name    string        `json:"name"`
-	Version string        `json:"version"`
-	Port    int           `json:"port"`
-	Status  InstanceState `json:"status"`
-
-	Cmd   *exec.Cmd   `json:"-"`
-	Stdin interface{} `json:"-"`
-}
-
 func CreateNewInstance(name string, version string, options VsServerConfigOptions, cfg *AppConfig) error {
 	instanceDir := filepath.Join(cfg.Storage.InstancesDir, name)