Return error while creating kubernetes client (kanisterio#3134)

pkg/function/backup_data.go

@@ -91,7 +91,10 @@ func (*backupDataFunc) Exec(ctx context.Context, tp param.TemplateParams, args m
 	if err = validateProfile(tp.Profile); err != nil {
 		return errors.Wrapf(err, "Failed to validate Profile")
 	}
-	cli := kube.NewClient()
+	cli, err := kube.NewClient()
+	if err != nil {
+		return errors.Wrapf(err, "Failed to create Kubernetes client")
+	}
 	// Create backup and dump it on the object store
 	cmd := generateBackupCommand(includePath, backupArtifact, tp.Profile)
 	stdout, stderr, err := kube.Exec(cli, namespace, pod, container, cmd)

pkg/function/kube_exec.go

@@ -34,10 +34,12 @@ func (*kubeExecFunc) Name() string {
 }
 
 func (kef *kubeExecFunc) Exec(ctx context.Context, tp param.TemplateParams, args map[string]interface{}) error {
-	cli := kube.NewClient()
+	cli, err := kube.NewClient()
+	if err != nil {
+		return err
+	}
 	var namespace, pod, container string
 	var cmd []string
-	var err error
 	if err = Arg(args, KubeExecNamespaceArg, &namespace); err != nil {
 		return err
 	}

pkg/function/kube_exec_all.go

@@ -36,10 +36,12 @@ func (*kubeExecAllFunc) Name() string {
 }
 
 func (*kubeExecAllFunc) Exec(ctx context.Context, tp param.TemplateParams, args map[string]interface{}) error {
-	cli := kube.NewClient()
+	cli, err := kube.NewClient()
+	if err != nil {
+		return err
+	}
 	var namespace, pods, containers string
 	var cmd []string
-	var err error
 	if err = Arg(args, KubeExecAllNamespaceArg, &namespace); err != nil {
 		return err
 	}

pkg/function/kube_task.go

@@ -55,7 +55,10 @@ func (ktf *kubeTaskFunc) Exec(ctx context.Context, tp param.TemplateParams, args
 	}
 
 	jobName := generateJobName(jobPrefix)
-	clientset := kube.NewClient()
+	clientset, err := kube.NewClient()
+	if err != nil {
+		return errors.Wrapf(err, "Failed to create Kubernetes client")
+	}
 	serviceAccount, err := kube.GetControllerServiceAccount(clientset)
 	if err != nil {
 		return errors.Wrap(err, "Failed to get Controller Service Account")

pkg/function/kube_task_test.go

@@ -23,7 +23,9 @@ type KubeTaskSuite struct {
 }
 
 func (s *KubeTaskSuite) SetUpSuite(c *C) {
-	s.cli = kube.NewClient()
+	cli, err := kube.NewClient()
+	c.Assert(err, IsNil)
+	s.cli = cli
 
 	ns := &v1.Namespace{
 		ObjectMeta: metav1.ObjectMeta{

pkg/function/prepare_data.go

@@ -50,7 +50,10 @@ func (*prepareDataFunc) Exec(ctx context.Context, tp param.TemplateParams, args
 	if err = OptArg(args, PrepareDataServiceAccount, &serviceAccount, ""); err != nil {
 		return err
 	}
-	cli := kube.NewClient()
+	cli, err := kube.NewClient()
+	if err != nil {
+		return errors.Wrapf(err, "Failed to create Kubernetes client")
+	}
 	// Validate volumes
 	for pvc := range vols {
 		if _, err := cli.CoreV1().PersistentVolumeClaims(namespace).Get(pvc, metav1.GetOptions{}); err != nil {

pkg/function/prepare_data_test.go

@@ -23,7 +23,9 @@ type PrepareDataSuite struct {
 }
 
 func (s *PrepareDataSuite) SetUpSuite(c *C) {
-	s.cli = kube.NewClient()
+	cli, err := kube.NewClient()
+	c.Assert(err, IsNil)
+	s.cli = cli
 
 	ns := &v1.Namespace{
 		ObjectMeta: metav1.ObjectMeta{

pkg/function/scale_workload.go

@@ -43,7 +43,10 @@ func (*scaleWorkloadFunc) Exec(ctx context.Context, tp param.TemplateParams, arg
 		return err
 	}
 
-	cli := kube.NewClient()
+	cli, err := kube.NewClient()
+	if err != nil {
+		return errors.Wrapf(err, "Failed to create Kubernetes client")
+	}
 	switch strings.ToLower(kind) {
 	case "statefulset":
 		return kube.ScaleStatefulSet(ctx, cli, namespace, name, replicas)

pkg/kube/client.go

@@ -36,17 +36,17 @@ func LoadConfig() (*rest.Config, error) {
 	return newClientConfig().ClientConfig()
 }
 
-// NewClient returns a k8 client configured by the k10 environment.
-func NewClient() kubernetes.Interface {
+// NewClient returns a k8 client configured by the kanister environment.
+func NewClient() (kubernetes.Interface, error) {
 	config, err := LoadConfig()
 	if err != nil {
-		panic(err.Error())
+		return nil, err
 	}
 
 	// creates the clientset
 	clientset, err := kubernetes.NewForConfig(config)
 	if err != nil {
-		panic(err.Error())
+		return nil, err
 	}
-	return clientset
+	return clientset, nil
 }

pkg/kube/exec_test.go

@@ -12,7 +12,8 @@ var _ = Suite(&ExecSuite{})
 
 func (s *ExecSuite) TestExecEcho(c *C) {
 	cmd := []string{"sh", "-c", "echo badabing"}
-	cli := NewClient()
+	cli, err := NewClient()
+	c.Assert(err, IsNil)
 	pods, err := cli.Core().Pods(defaultNamespace).List(emptyListOptions)
 	c.Assert(err, IsNil)
 	if len(pods.Items) == 0 {

pkg/kube/job_test.go

@@ -31,7 +31,8 @@ func (s *JobSuite) SetUpSuite(c *C) {
 
 // Verifies that the Job object is not created if the job name is not specified.
 func (s *JobSuite) TestJobsNoName(c *C) {
-	clientset := NewClient()
+	clientset, err := NewClient()
+	c.Assert(err, IsNil)
 
 	job, err := NewJob(clientset, testJobName, testJobNamespace, testJobServiceAccount, "", nil, "sleep", "10")
 	c.Assert(job, IsNil)
@@ -40,7 +41,8 @@ func (s *JobSuite) TestJobsNoName(c *C) {
 
 // Verifies that the Job object is not created if the image is not specified.
 func (s *JobSuite) TestJobsNoImage(c *C) {
-	clientset := NewClient()
+	clientset, err := NewClient()
+	c.Assert(err, IsNil)
 
 	job, err := NewJob(clientset, testJobName, testJobNamespace, testJobServiceAccount, "", nil, "sleep", "10")
 	c.Assert(job, IsNil)
@@ -49,7 +51,8 @@ func (s *JobSuite) TestJobsNoImage(c *C) {
 
 // Verifies that the Job object is not created if the namespace is not specified.
 func (s *JobSuite) TestJobsNoNamespace(c *C) {
-	clientset := NewClient()
+	clientset, err := NewClient()
+	c.Assert(err, IsNil)
 
 	job, err := NewJob(clientset, testJobName, "", testJobServiceAccount, testJobImage, nil, "sleep", "10")
 	c.Assert(job.namespace, Equals, "default")
@@ -65,7 +68,8 @@ func (s *JobSuite) TestJobsNoClientset(c *C) {
 
 // Verifies that the Job object is not created if the command is not passed.
 func (s *JobSuite) TestJobsNoCommand(c *C) {
-	clientset := NewClient()
+	clientset, err := NewClient()
+	c.Assert(err, IsNil)
 
 	job, err := NewJob(clientset, testJobName, testJobNamespace, testJobServiceAccount, testJobImage, nil, "")
 	c.Assert(job, IsNil)
@@ -109,7 +113,8 @@ func waitForJobCount(clientset kubernetes.Interface, namespace string, expectedC
 // Verifies that the basic Job creation and deletion completes successfully.
 func (s *JobSuite) TestJobsBasic(c *C) {
 	namespace := "default"
-	clientset := NewClient()
+	clientset, err := NewClient()
+	c.Assert(err, IsNil)
 
 	origJobCount := getK8sJobCount(clientset, namespace, c)
 
@@ -140,7 +145,8 @@ func (s *JobSuite) TestJobsBasic(c *C) {
 // Verifies that deleting the Job while it is running works.
 func (s *JobSuite) TestJobsDeleteWhileRunning(c *C) {
 	namespace := "default"
-	clientset := NewClient()
+	clientset, err := NewClient()
+	c.Assert(err, IsNil)
 
 	job, err := NewJob(clientset, testJobName, testJobNamespace, testJobServiceAccount, testJobImage, nil, "sleep", "300")
 
@@ -165,7 +171,8 @@ func cancelLater(cancel func()) {
 
 // Verifies that cancelling the context results in WaitForCompletion finishing.
 func (s *JobSuite) TestJobsWaitAfterDelete(c *C) {
-	clientset := NewClient()
+	clientset, err := NewClient()
+	c.Assert(err, IsNil)
 
 	job, err := NewJob(clientset, testJobName, testJobNamespace, testJobServiceAccount, testJobImage, nil, "sleep", "300")
 
@@ -188,7 +195,8 @@ func (s *JobSuite) TestJobsWaitAfterDelete(c *C) {
 }
 
 func (s *JobSuite) TestJobsWaitOnNonExistentJob(c *C) {
-	clientset := NewClient()
+	clientset, err := NewClient()
+	c.Assert(err, IsNil)
 
 	job, err := NewJob(clientset, testJobName, testJobNamespace, testJobServiceAccount, testJobImage, nil, "sleep", "300")
 

pkg/kube/statefulset_test.go

@@ -22,7 +22,9 @@ var _ = Suite(&StatefulSetSuite{})
 
 func (s *StatefulSetSuite) SetUpSuite(c *C) {
 	c.Skip("Too slow")
-	s.cli = NewClient()
+	cli, err := NewClient()
+	c.Assert(err, IsNil)
+	s.cli = cli
 	ns := &v1.Namespace{
 		ObjectMeta: metav1.ObjectMeta{
 			GenerateName: "statefulsettest-",

pkg/param/param_test.go

@@ -30,7 +30,9 @@ type ParamsSuite struct {
 var _ = Suite(&ParamsSuite{})
 
 func (s *ParamsSuite) SetUpSuite(c *C) {
-	s.cli = kube.NewClient()
+	cli, err := kube.NewClient()
+	c.Assert(err, IsNil)
+	s.cli = cli
 	ns := &v1.Namespace{
 		ObjectMeta: metav1.ObjectMeta{
 			GenerateName: "kanisterparamstest-",

pkg/resource/resource_test.go

@@ -25,7 +25,9 @@ type ResourceSuite struct {
 var _ = Suite(&ResourceSuite{})
 
 func (s *ResourceSuite) SetUpSuite(c *C) {
-	s.cli = kube.NewClient()
+	cli, err := kube.NewClient()
+	c.Assert(err, IsNil)
+	s.cli = cli
 	ns := &v1.Namespace{
 		ObjectMeta: metav1.ObjectMeta{
 			GenerateName: "kanistercontrollertest-",