Added api discovery to kubectl run, based on which we decide which generators to use

docs/man/man1/kubectl-run.1

@@ -40,7 +40,7 @@ Creates a deployment or job to manage the created container(s).
 
 .PP
 \fB\-\-generator\fP=""
-    The name of the API generator to use.  Default is 'deployment/v1beta1' if \-\-restart=Always, otherwise the default is 'job/v1'.
+    The name of the API generator to use.  Default is 'deployment/v1beta1' if \-\-restart=Always, otherwise the default is 'job/v1'.  This will happen only for cluster version at least 1.2, for olders we will fallback to 'run/v1' for \-\-restart=Alwyas, 'run\-pod/v1' for others.
 
 .PP
 \fB\-\-hostport\fP=\-1

docs/user-guide/kubectl/kubectl_run.md

@@ -88,7 +88,7 @@ kubectl run pi --image=perl --restart=OnFailure -- perl -Mbignum=bpi -wle 'print
       --dry-run[=false]: If true, only print the object that would be sent, without sending it.
       --env=[]: Environment variables to set in the container
       --expose[=false]: If true, a public, external service is created for the container(s) which are run
-      --generator="": The name of the API generator to use.  Default is 'deployment/v1beta1' if --restart=Always, otherwise the default is 'job/v1'.
+      --generator="": The name of the API generator to use.  Default is 'deployment/v1beta1' if --restart=Always, otherwise the default is 'job/v1'.  This will happen only for cluster version at least 1.2, for olders we will fallback to 'run/v1' for --restart=Alwyas, 'run-pod/v1' for others.
       --hostport=-1: The host port mapping for the container port. To demonstrate a single-machine container.
       --image="": The image for the container to run.
   -l, --labels="": Labels to apply to the pod(s).
@@ -147,7 +147,7 @@ kubectl run pi --image=perl --restart=OnFailure -- perl -Mbignum=bpi -wle 'print
 
 * [kubectl](kubectl.md)	 - kubectl controls the Kubernetes cluster manager
 
-###### Auto generated by spf13/cobra on 29-Feb-2016
+###### Auto generated by spf13/cobra on 11-Mar-2016
 
 <!-- BEGIN MUNGE: GENERATED_ANALYTICS -->
 [![Analytics](https://kubernetes-site.appspot.com/UA-36037335-10/GitHub/docs/user-guide/kubectl/kubectl_run.md?pixel)]()

pkg/kubectl/cmd/run.go

@@ -25,6 +25,9 @@ import (
 	"github.com/spf13/cobra"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/meta"
+	"k8s.io/kubernetes/pkg/api/unversioned"
+	batchv1 "k8s.io/kubernetes/pkg/apis/batch/v1"
+	"k8s.io/kubernetes/pkg/apis/extensions/v1beta1"
 	client "k8s.io/kubernetes/pkg/client/unversioned"
 	"k8s.io/kubernetes/pkg/kubectl"
 	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
@@ -88,7 +91,7 @@ func NewCmdRun(f *cmdutil.Factory, cmdIn io.Reader, cmdOut, cmdErr io.Writer) *c
 }
 
 func addRunFlags(cmd *cobra.Command) {
-	cmd.Flags().String("generator", "", "The name of the API generator to use.  Default is 'deployment/v1beta1' if --restart=Always, otherwise the default is 'job/v1'.")
+	cmd.Flags().String("generator", "", "The name of the API generator to use.  Default is 'deployment/v1beta1' if --restart=Always, otherwise the default is 'job/v1'.  This will happen only for cluster version at least 1.2, for olders we will fallback to 'run/v1' for --restart=Alwyas, 'run-pod/v1' for others.")
 	cmd.Flags().String("image", "", "The image for the container to run.")
 	cmd.MarkFlagRequired("image")
 	cmd.Flags().IntP("replicas", "r", 1, "Number of replicas to create for this container. Default is 1.")
@@ -146,10 +149,29 @@ func Run(f *cmdutil.Factory, cmdIn io.Reader, cmdOut, cmdErr io.Writer, cmd *cob
 
 	generatorName := cmdutil.GetFlagString(cmd, "generator")
 	if len(generatorName) == 0 {
+		client, err := f.Client()
+		if err != nil {
+			return err
+		}
+		resourcesList, err := client.Discovery().ServerResources()
+		if err != nil {
+			// this cover the cases where old servers do not expose discovery
+			resourcesList = nil
+		}
 		if restartPolicy == api.RestartPolicyAlways {
+			if contains(resourcesList, v1beta1.SchemeGroupVersion.WithResource("deployments")) {
 				generatorName = "deployment/v1beta1"
 			} else {
+				generatorName = "run/v1"
+			}
+		} else {
+			if contains(resourcesList, batchv1.SchemeGroupVersion.WithResource("jobs")) {
 				generatorName = "job/v1"
+			} else if contains(resourcesList, v1beta1.SchemeGroupVersion.WithResource("jobs")) {
+				generatorName = "job/v1beta1"
+			} else {
+				generatorName = "run-pod/v1"
+			}
 		}
 	}
 	generators := f.Generators("run")
@@ -254,6 +276,23 @@ func Run(f *cmdutil.Factory, cmdIn io.Reader, cmdOut, cmdErr io.Writer, cmd *cob
 	return nil
 }
 
+// TODO turn this into reusable method checking available resources
+func contains(resourcesList map[string]*unversioned.APIResourceList, resource unversioned.GroupVersionResource) bool {
+	if resourcesList == nil {
+		return false
+	}
+	resourcesGroup, ok := resourcesList[resource.GroupVersion().String()]
+	if !ok {
+		return false
+	}
+	for _, item := range resourcesGroup.APIResources {
+		if resource.Resource == item.Name {
+			return true
+		}
+	}
+	return false
+}
+
 func waitForPodRunning(c *client.Client, pod *api.Pod, out io.Writer) (status api.PodPhase, err error) {
 	for {
 		pod, err := c.Pods(pod.Namespace).Get(pod.Name)