Fixes #47538: Add functionality for manually creating a Job instance from a CronJob

This changeset adds the command `kubectl create job` with the flag `--from-cronjob`, which allows a user to create a Job from a CronJob via the CLI.

docs/.generated_docs

@@ -172,6 +172,7 @@ docs/man/man1/kubectl-create-clusterrole.1
 docs/man/man1/kubectl-create-clusterrolebinding.1
 docs/man/man1/kubectl-create-configmap.1
 docs/man/man1/kubectl-create-deployment.1
+docs/man/man1/kubectl-create-job.1
 docs/man/man1/kubectl-create-namespace.1
 docs/man/man1/kubectl-create-poddisruptionbudget.1
 docs/man/man1/kubectl-create-priorityclass.1
@@ -272,6 +273,7 @@ docs/user-guide/kubectl/kubectl_create_clusterrole.md
 docs/user-guide/kubectl/kubectl_create_clusterrolebinding.md
 docs/user-guide/kubectl/kubectl_create_configmap.md
 docs/user-guide/kubectl/kubectl_create_deployment.md
+docs/user-guide/kubectl/kubectl_create_job.md
 docs/user-guide/kubectl/kubectl_create_namespace.md
 docs/user-guide/kubectl/kubectl_create_poddisruptionbudget.md
 docs/user-guide/kubectl/kubectl_create_priorityclass.md

docs/man/man1/kubectl-create-job.1

@@ -0,0 +1,3 @@
+This file is autogenerated, but we've stopped checking such files into the
+repository to reduce the need for rebases. Please run hack/generate-docs.sh to
+populate this file.

docs/user-guide/kubectl/kubectl_create_job.md

@@ -0,0 +1,3 @@
+This file is autogenerated, but we've stopped checking such files into the
+repository to reduce the need for rebases. Please run hack/generate-docs.sh to
+populate this file.

pkg/kubectl/cmd/BUILD

@@ -28,6 +28,7 @@ go_library(
         "create_clusterrolebinding.go",
         "create_configmap.go",
         "create_deployment.go",
+        "create_job.go",
         "create_namespace.go",
         "create_pdb.go",
         "create_priorityclass.go",
@@ -132,6 +133,7 @@ go_library(
         "//vendor/k8s.io/apimachinery/pkg/util/jsonmergepatch:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/mergepatch:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/net:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/rand:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/strategicpatch:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/validation:go_default_library",
@@ -142,6 +144,8 @@ go_library(
         "//vendor/k8s.io/apiserver/pkg/util/flag:go_default_library",
         "//vendor/k8s.io/client-go/discovery:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes:go_default_library",
+        "//vendor/k8s.io/client-go/kubernetes/typed/batch/v1:go_default_library",
+        "//vendor/k8s.io/client-go/kubernetes/typed/batch/v1beta1:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes/typed/core/v1:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes/typed/rbac/v1:go_default_library",
         "//vendor/k8s.io/client-go/rest:go_default_library",
@@ -171,6 +175,7 @@ go_test(
         "create_clusterrolebinding_test.go",
         "create_configmap_test.go",
         "create_deployment_test.go",
+        "create_job_test.go",
         "create_namespace_test.go",
         "create_pdb_test.go",
         "create_priorityclass_test.go",
@@ -231,6 +236,8 @@ go_test(
         "//vendor/github.com/spf13/cobra:go_default_library",
         "//vendor/github.com/stretchr/testify/assert:go_default_library",
         "//vendor/gopkg.in/yaml.v2:go_default_library",
+        "//vendor/k8s.io/api/batch/v1:go_default_library",
+        "//vendor/k8s.io/api/batch/v1beta1:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",
         "//vendor/k8s.io/api/policy/v1beta1:go_default_library",
         "//vendor/k8s.io/api/rbac/v1:go_default_library",
@@ -252,6 +259,7 @@ go_test(
         "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/version:go_default_library",
         "//vendor/k8s.io/client-go/dynamic:go_default_library",
+        "//vendor/k8s.io/client-go/kubernetes/fake:go_default_library",
         "//vendor/k8s.io/client-go/rest:go_default_library",
         "//vendor/k8s.io/client-go/rest/fake:go_default_library",
         "//vendor/k8s.io/client-go/testing:go_default_library",

pkg/kubectl/cmd/create.go

@@ -115,6 +115,7 @@ func NewCmdCreate(f cmdutil.Factory, out, errOut io.Writer) *cobra.Command {
 	cmd.AddCommand(NewCmdCreateRoleBinding(f, out))
 	cmd.AddCommand(NewCmdCreatePodDisruptionBudget(f, out))
 	cmd.AddCommand(NewCmdCreatePriorityClass(f, out))
+	cmd.AddCommand(NewCmdCreateJob(f, out))
 	return cmd
 }
 

pkg/kubectl/cmd/create_job.go

@@ -0,0 +1,147 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cmd
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/spf13/cobra"
+
+	batchv1 "k8s.io/api/batch/v1"
+	"k8s.io/apimachinery/pkg/api/meta"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/rand"
+	clientbatchv1 "k8s.io/client-go/kubernetes/typed/batch/v1"
+	clientbatchv1beta1 "k8s.io/client-go/kubernetes/typed/batch/v1beta1"
+	"k8s.io/kubernetes/pkg/kubectl/cmd/templates"
+	cmdutil "k8s.io/kubernetes/pkg/kubectl/cmd/util"
+	"k8s.io/kubernetes/pkg/kubectl/util/i18n"
+)
+
+var (
+	jobLong = templates.LongDesc(i18n.T(`
+		Create a Job to execute immediately from a specified CronJob.`))
+
+	jobExample = templates.Examples(i18n.T(`
+		# Create a Job from a CronJob named "a-cronjob"
+		kubectl create job --from-cronjob=a-cronjob`))
+)
+
+type CreateJobOptions struct {
+	FromCronJob string
+
+	OutputFormat  string
+	Namespace     string
+	V1Beta1Client clientbatchv1beta1.BatchV1beta1Interface
+	V1Client      clientbatchv1.BatchV1Interface
+	Mapper        meta.RESTMapper
+	Out           io.Writer
+	PrintObject   func(obj runtime.Object) error
+	PrintSuccess  func(mapper meta.RESTMapper, shortOutput bool, out io.Writer, resource, name string, dryRun bool, operation string)
+}
+
+// NewCmdCreateJob is a command to ease creating Jobs from CronJobs.
+func NewCmdCreateJob(f cmdutil.Factory, cmdOut io.Writer) *cobra.Command {
+	c := &CreateJobOptions{
+		Out: cmdOut,
+	}
+	cmd := &cobra.Command{
+		Use:     "job --from-cronjob=CRONJOB",
+		Short:   jobLong,
+		Long:    jobLong,
+		Example: jobExample,
+		Run: func(cmd *cobra.Command, args []string) {
+			cmdutil.CheckErr(c.Complete(f, cmd, args))
+			cmdutil.CheckErr(c.RunCreateJob())
+		},
+	}
+	cmdutil.AddApplyAnnotationFlags(cmd)
+	cmdutil.AddValidateFlags(cmd)
+	cmdutil.AddPrinterFlags(cmd)
+	cmd.Flags().String("from-cronjob", "", "Specify the name of the CronJob to create a Job from.")
+
+	return cmd
+}
+
+func (c *CreateJobOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) (err error) {
+	c.FromCronJob = cmdutil.GetFlagString(cmd, "from-cronjob")
+
+	// Complete other options for Run.
+	c.Mapper, _ = f.Object()
+
+	c.OutputFormat = cmdutil.GetFlagString(cmd, "output")
+
+	c.Namespace, _, err = f.DefaultNamespace()
+	if err != nil {
+		return err
+	}
+
+	c.PrintObject = func(obj runtime.Object) error {
+		return f.PrintObject(cmd, obj, c.Out)
+	}
+
+	// need two client sets to deal with the differing versions of CronJobs and Jobs
+	clientset, err := f.KubernetesClientSet()
+	if err != nil {
+		return err
+	}
+	if c.V1Client == nil {
+		c.V1Client = clientset.BatchV1()
+	}
+	if c.V1Beta1Client == nil {
+		c.V1Beta1Client = clientset.BatchV1beta1()
+	}
+
+	return nil
+}
+
+func (c *CreateJobOptions) RunCreateJob() (err error) {
+	cronjob, err := c.V1Beta1Client.CronJobs(c.Namespace).Get(c.FromCronJob, metav1.GetOptions{})
+
+	if err != nil {
+		return fmt.Errorf("failed to fetch job: %v", err)
+	}
+
+	annotations := make(map[string]string)
+	annotations["cronjob.kubernetes.io/instantiate"] = "manual"
+
+	labels := make(map[string]string)
+	for k, v := range cronjob.Spec.JobTemplate.Labels {
+		labels[k] = v
+	}
+
+	jobToCreate := &batchv1.Job{
+		ObjectMeta: metav1.ObjectMeta{
+			// job name cannot exceed DNS1053LabelMaxLength (52 characters)
+			Name:        cronjob.Name + "-manual-" + rand.String(3),
+			Namespace:   c.Namespace,
+			Annotations: annotations,
+			Labels:      labels,
+		},
+		Spec: cronjob.Spec.JobTemplate.Spec,
+	}
+
+	result, err := c.V1Client.Jobs(c.Namespace).Create(jobToCreate)
+
+	if err != nil {
+		return fmt.Errorf("failed to create job: %v", err)
+	}
+
+	return c.PrintObject(result)
+}

pkg/kubectl/cmd/create_job_test.go

@@ -0,0 +1,149 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cmd
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+	"testing"
+
+	"k8s.io/apimachinery/pkg/runtime"
+
+	batchv1 "k8s.io/api/batch/v1"
+	batchv1beta1 "k8s.io/api/batch/v1beta1"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	fake "k8s.io/client-go/kubernetes/fake"
+	clienttesting "k8s.io/client-go/testing"
+	cmdtesting "k8s.io/kubernetes/pkg/kubectl/cmd/testing"
+)
+
+var submittedJob *batchv1.Job
+
+func TestCreateJobFromCronJob(t *testing.T) {
+	testNamespaceName := "test"
+	testCronJobName := "test-cronjob"
+	testImageName := "fake"
+
+	expectedLabels := make(map[string]string)
+	expectedAnnotations := make(map[string]string)
+	expectedLabels["test-label"] = "test-value"
+	expectedAnnotations["cronjob.kubernetes.io/instantiate"] = "manual"
+
+	expectJob := &batchv1.Job{
+		ObjectMeta: metav1.ObjectMeta{
+			Namespace:   testNamespaceName,
+			Labels:      expectedLabels,
+			Annotations: expectedAnnotations,
+		},
+		Spec: batchv1.JobSpec{
+			Template: corev1.PodTemplateSpec{
+				Spec: corev1.PodSpec{
+					Containers: []corev1.Container{
+						{Image: testImageName},
+					},
+				},
+			},
+		},
+	}
+
+	cronJobToCreate := &batchv1beta1.CronJob{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      testCronJobName,
+			Namespace: testNamespaceName,
+		},
+		Spec: batchv1beta1.CronJobSpec{
+			Schedule: "* * * * *",
+			JobTemplate: batchv1beta1.JobTemplateSpec{
+				ObjectMeta: metav1.ObjectMeta{
+					Namespace: testNamespaceName,
+					Labels:    expectedLabels,
+				},
+				Spec: expectJob.Spec,
+			},
+		},
+	}
+
+	clientset := fake.Clientset{}
+	clientset.PrependReactor("get", "cronjobs", func(action clienttesting.Action) (handled bool, ret runtime.Object, err error) {
+		return true, cronJobToCreate, nil
+	})
+	clientset.PrependReactor("create", "jobs", func(action clienttesting.Action) (handled bool, ret runtime.Object, err error) {
+		ca := action.(clienttesting.CreateAction)
+		submittedJob = ca.GetObject().(*batchv1.Job)
+		return true, expectJob, nil
+	})
+
+	f, _, _, _ := cmdtesting.NewAPIFactory()
+	buf := bytes.NewBuffer([]byte{})
+
+	mapper, _ := f.Object()
+	cmdOptions := &CreateJobOptions{
+		Out:           buf,
+		OutputFormat:  "na",
+		Namespace:     testNamespaceName,
+		FromCronJob:   testCronJobName,
+		V1Client:      clientset.BatchV1(),
+		V1Beta1Client: clientset.BatchV1beta1(),
+		Mapper:        mapper,
+		PrintObject: func(obj runtime.Object) error {
+			return nil
+		},
+	}
+	cmdOptions.RunCreateJob()
+
+	composedJobName := fmt.Sprintf("%s-manual-", testCronJobName)
+	if !strings.HasPrefix(submittedJob.ObjectMeta.Name, composedJobName) {
+		t.Errorf("expected '%s', got '%s'", composedJobName, submittedJob.ObjectMeta.Name)
+	}
+
+	annotationsArrayLength := len(submittedJob.Annotations)
+	if annotationsArrayLength != 1 {
+		t.Errorf("expected length of annotations array to be 1, got %d", annotationsArrayLength)
+	}
+
+	if v, ok := submittedJob.Annotations["cronjob.kubernetes.io/instantiate"]; ok {
+		if v != "manual" {
+			t.Errorf("expected annotation cronjob.kubernetes.io/instantiate to be 'manual', got '%s'", v)
+		}
+	} else {
+		t.Errorf("expected annotation cronjob.kubernetes.io/instantiate to exist")
+	}
+
+	labelsArrayLength := len(submittedJob.Labels)
+	if labelsArrayLength != 1 {
+		t.Errorf("expected length of labels array to be 1, got %d", labelsArrayLength)
+	}
+
+	if v, ok := submittedJob.Labels["test-label"]; ok {
+		if v != "test-value" {
+			t.Errorf("expected label test-label to be 'test-value', got '%s'", v)
+		}
+	} else {
+		t.Errorf("expected label test-label to exist")
+	}
+
+	containerArrayLength := len(submittedJob.Spec.Template.Spec.Containers)
+	if containerArrayLength != 1 {
+		t.Errorf("expected length of container array to be 1, got %d", containerArrayLength)
+	}
+
+	if submittedJob.Spec.Template.Spec.Containers[0].Image != testImageName {
+		t.Errorf("expected '%s', got '%s'", testImageName, submittedJob.Spec.Template.Spec.Containers[0].Image)
+	}
+}