fix infinite loop in init-pytorch container

cmd/training-operator.v1/main.go

@@ -85,6 +85,8 @@ func main() {
 		config.PyTorchInitContainerImageDefault, "The image for pytorch init container")
 	flag.StringVar(&config.Config.PyTorchInitContainerTemplateFile, "pytorch-init-container-template-file",
 		config.PyTorchInitContainerTemplateFileDefault, "The template file for pytorch init container")
+	flag.IntVar(&config.Config.PyTorchInitContainerMaxTries, "pytorch-init-container-try-number",
+		config.PyTorchInitContainerMaxTriesDefault, "The number of tries for the pytorch init container")
 
 	// MPI related flags
 	flag.StringVar(&config.Config.MPIKubectlDeliveryImage, "mpi-kubectl-delivery-image",

pkg/config/config.go

@@ -19,6 +19,7 @@ var Config struct {
 	PyTorchInitContainerTemplateFile string
 	PyTorchInitContainerImage        string
 	MPIKubectlDeliveryImage          string
+	PyTorchInitContainerMaxTries     int
 }
 
 const (
@@ -28,6 +29,8 @@ const (
 	// PyTorchInitContainerTemplateFileDefault is the default template file for
 	// the pytorch init container.
 	PyTorchInitContainerTemplateFileDefault = "/etc/config/initContainer.yaml"
+	// PyTorchInitContainerMaxTriesDefault is the default number of tries for the pytorch init container.
+	PyTorchInitContainerMaxTriesDefault = 100
 	// MPIKubectlDeliveryImageDefault is the default image for launcher pod in MPIJob init container.
 	MPIKubectlDeliveryImageDefault = "mpioperator/kubectl-delivery:latest"
 )

pkg/controller.v1/pytorch/initcontainer.go

@@ -43,21 +43,23 @@ var (
     requests:
       cpu: 50m
       memory: 10Mi
-  command: ['sh', '-c', 'until nslookup {{.MasterAddr}}; do echo waiting for master; sleep 2; done;']`
+  command: ['sh', '-c', 'err=1;for i in $(seq {{.MaxTries}}); do if nslookup {{.MasterAddr}}; then err=0 && break; fi;echo waiting for master; sleep 2; done; exit $err']`
 	onceInitContainer sync.Once
 	icGenerator       *initContainerGenerator
 )
 
 type initContainerGenerator struct {
 	template string
 	image    string
+	maxTries int
 }
 
 func getInitContainerGenerator() *initContainerGenerator {
 	onceInitContainer.Do(func() {
 		icGenerator = &initContainerGenerator{
 			template: getInitContainerTemplateOrDefault(config.Config.PyTorchInitContainerTemplateFile),
 			image:    config.Config.PyTorchInitContainerImage,
+			maxTries: config.Config.PyTorchInitContainerMaxTries,
 		}
 	})
 	return icGenerator
@@ -72,9 +74,11 @@ func (i *initContainerGenerator) GetInitContainer(masterAddr string) ([]corev1.C
 	if err := tpl.Execute(&buf, struct {
 		MasterAddr         string
 		InitContainerImage string
+		MaxTries           int
 	}{
 		MasterAddr:         masterAddr,
 		InitContainerImage: i.image,
+		MaxTries:           i.maxTries,
 	}); err != nil {
 		return nil, err
 	}

pkg/controller.v1/pytorch/initcontainer_test.go

@@ -34,6 +34,7 @@ func TestInitContainer(t *testing.T) {
 
 	config.Config.PyTorchInitContainerImage = config.PyTorchInitContainerImageDefault
 	config.Config.PyTorchInitContainerTemplateFile = config.PyTorchInitContainerTemplateFileDefault
+	config.Config.PyTorchInitContainerMaxTries = config.PyTorchInitContainerMaxTriesDefault
 
 	testCases := []struct {
 		job         *kubeflowv1.PyTorchJob