Reduce a number of creating connection

server/pkg/lxdclient/connect.go

@@ -79,6 +79,11 @@ var (
 // ConnectLXDWithTimeout connect LXD API with timeout
 // lxd.ConnectLXD is not support context yet. So ConnectLXDWithTimeout occurred goroutine leak if timeout.
 func ConnectLXDWithTimeout(host, clientCert, clientKey string) (*lxd.InstanceServer, error) {
+	client, ok := loadConnectedInstance(host)
+	if ok {
+		return client, nil
+	}
+
 	type resultConnectLXD struct {
 		client lxd.InstanceServer
 		err    error
@@ -105,9 +110,32 @@ func ConnectLXDWithTimeout(host, clientCert, clientKey string) (*lxd.InstanceSer
 		if result.err != nil {
 			return nil, fmt.Errorf("failed to connect LXD: %w", result.err)
 		}
+
+		storeConnectedInstance(host, result.client)
+
 		return &result.client, nil
 	case <-time.After(2 * time.Second):
 		// lxd.ConnectLXD() is not support context.Context yet. need to refactor it after support context.Context.
 		return nil, ErrTimeoutConnectLXD
 	}
 }
+
+// connectedInstances is map of connected LXD instances
+// key: lxdhost value: LXDHost
+var connectedInstances sync.Map
+
+// storeConnectedInstance store connected instance
+func storeConnectedInstance(host string, lh lxd.InstanceServer) {
+	connectedInstances.Store(host, lh)
+}
+
+// loadConnectedInstance load connected instance
+func loadConnectedInstance(host string) (*lxd.InstanceServer, bool) {
+	v, ok := connectedInstances.Load(host)
+	if !ok {
+		return nil, false
+	}
+	i := v.(lxd.InstanceServer)
+
+	return &i, true
+}