Cleanup; Adding locks where needed, and checking port availibility

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)