feat: add context switching in TestStep (#560)

Signed-off-by: Kumar Mallikarjuna <kumarmallikarjuna.work@gmail.com>

docs/testing/reference.md

@@ -64,17 +64,18 @@ kubeconfig: foo.kubeconfig
 
 Supported settings:
 
-Field    |          Type             | Description
----------|---------------------------|---------------------------------------------------------------------
-apply    | list of files             | A list of files to apply as part of this step. Specified path is relative to that in which the step occurs.
-assert   | list of files             | A list of files to assert as part of this step. See documentation for [asserts and errors](asserts-errors.md) for more information. Specified path is relative to that in which the step occurs.
-error    | list of files             | A list of files to error as part of this step. See documentation for [asserts and errors](asserts-errors.md) for more information. Specified path is relative to that in which the step occurs.
-delete   | list of object references | A list of objects to delete, if they do not already exist, at the beginning of the test step. The test harness will wait for the objects to be successfully deleted before applying the objects in the step.
-index    | int                       | Override the test step's index.
+Field    | Type                          | Description
+---------|-------------------------------|---------------------------------------------------------------------
+apply    | list of files                 | A list of files to apply as part of this step. Specified path is relative to that in which the step occurs.
+assert   | list of files                 | A list of files to assert as part of this step. See documentation for [asserts and errors](asserts-errors.md) for more information. Specified path is relative to that in which the step occurs.
+error    | list of files                 | A list of files to error as part of this step. See documentation for [asserts and errors](asserts-errors.md) for more information. Specified path is relative to that in which the step occurs.
+delete   | list of object references     | A list of objects to delete, if they do not already exist, at the beginning of the test step. The test harness will wait for the objects to be successfully deleted before applying the objects in the step.
+index    | int                           | Override the test step's index.
 commands | list of [Commands](#commands) | Commands to run prior at the beginning of the test step.
-kubeconfig    | string                       | The Kubeconfig file to use to run the included steps(s).
-kubeconfigLoading    | string                | Specifies the mode for loading Kubeconfig and making a cluster connection: `Eager` (when loading the test definition) or `Lazy` (right before executing the step, makes it possible to generate the Kubeconfig in a preceding step). Defaults to `Eager`.
-unitTest    | bool                       | Indicates if the step is a unit test, safe to run without a real Kubernetes cluster.
+kubeconfig    | string                        | The Kubeconfig file to use to run the included steps(s).
+kubeconfigLoading    | string                        | Specifies the mode for loading Kubeconfig and making a cluster connection: `Eager` (when loading the test definition) or `Lazy` (right before executing the step, makes it possible to generate the Kubeconfig in a preceding step). Defaults to `Eager`.
+context     | string                        | Specifies the context to use from the Kubeconfig.
+unitTest    | bool                          | Indicates if the step is a unit test, safe to run without a real Kubernetes cluster.
 
 
 Object Reference:

pkg/apis/testharness/v1beta1/test_types.go

@@ -133,6 +133,9 @@ type TestStep struct {
 	// +kubebuilder:default=Eager
 	// +kubebuilder:validation:Enum=Eager;Lazy
 	KubeconfigLoading string `json:"kubeconfigLoading,omitempty"`
+
+	// Specifies the context to use from the Kubeconfig.
+	Context string `json:"context,omitempty"`
 }
 
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object

pkg/k8s/main.go

@@ -2,6 +2,7 @@ package k8s
 
 import (
 	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
 	"sigs.k8s.io/controller-runtime/pkg/client/config"
 )
 
@@ -19,3 +20,14 @@ func GetConfig() (*rest.Config, error) {
 
 	return cfg, nil
 }
+
+func BuildConfigWithContext(kubeconfig, context string) (*rest.Config, error) {
+	if context == "" {
+		// Use default context
+		return clientcmd.BuildConfigFromFlags("", kubeconfig)
+	}
+
+	return clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
+		&clientcmd.ClientConfigLoadingRules{ExplicitPath: kubeconfig},
+		&clientcmd.ConfigOverrides{CurrentContext: context}).ClientConfig()
+}

pkg/test/case.go

@@ -23,9 +23,8 @@ import (
 	"k8s.io/client-go/discovery"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 
-	"k8s.io/client-go/tools/clientcmd"
-
 	"github.com/kudobuilder/kuttl/pkg/apis/testharness/v1beta1"
+	"github.com/kudobuilder/kuttl/pkg/k8s"
 	"github.com/kudobuilder/kuttl/pkg/report"
 	testutils "github.com/kudobuilder/kuttl/pkg/test/utils"
 )
@@ -338,7 +337,7 @@ func (t *Case) Run(test *testing.T, ts *report.Testsuite) {
 			continue
 		}
 
-		cl, err = newClient(testStep.Kubeconfig)(false)
+		cl, err = newClient(testStep.Kubeconfig, testStep.Context)(false)
 		if err != nil {
 			setupReport.Failure = report.NewFailure(err.Error(), nil)
 			ts.AddTestcase(setupReport)
@@ -363,11 +362,11 @@ func (t *Case) Run(test *testing.T, ts *report.Testsuite) {
 		tc := report.NewCase("step " + testStep.String())
 		testStep.Client = t.Client
 		if testStep.Kubeconfig != "" {
-			testStep.Client = newClient(testStep.Kubeconfig)
+			testStep.Client = newClient(testStep.Kubeconfig, testStep.Context)
 		}
 		testStep.DiscoveryClient = t.DiscoveryClient
 		if testStep.Kubeconfig != "" {
-			testStep.DiscoveryClient = newDiscoveryClient(testStep.Kubeconfig)
+			testStep.DiscoveryClient = newDiscoveryClient(testStep.Kubeconfig, testStep.Context)
 		}
 		testStep.Logger = t.Logger.WithPrefix(testStep.String())
 		tc.Assertions += len(testStep.Asserts)
@@ -531,9 +530,9 @@ func (t *Case) LoadTestSteps() error {
 	return nil
 }
 
-func newClient(kubeconfig string) func(bool) (client.Client, error) {
+func newClient(kubeconfig, context string) func(bool) (client.Client, error) {
 	return func(bool) (client.Client, error) {
-		config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
+		config, err := k8s.BuildConfigWithContext(kubeconfig, context)
 		if err != nil {
 			return nil, err
 		}
@@ -544,9 +543,9 @@ func newClient(kubeconfig string) func(bool) (client.Client, error) {
 	}
 }
 
-func newDiscoveryClient(kubeconfig string) func() (discovery.DiscoveryInterface, error) {
+func newDiscoveryClient(kubeconfig, context string) func() (discovery.DiscoveryInterface, error) {
 	return func() (discovery.DiscoveryInterface, error) {
-		config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
+		config, err := k8s.BuildConfigWithContext(kubeconfig, context)
 		if err != nil {
 			return nil, err
 		}

pkg/test/step.go

@@ -53,8 +53,10 @@ type Step struct {
 
 	Kubeconfig        string
 	KubeconfigLoading string
-	Client            func(forceNew bool) (client.Client, error)
-	DiscoveryClient   func() (discovery.DiscoveryInterface, error)
+	Context           string
+
+	Client          func(forceNew bool) (client.Client, error)
+	DiscoveryClient func() (discovery.DiscoveryInterface, error)
 
 	Logger testutils.Logger
 }
@@ -556,6 +558,7 @@ func (s *Step) LoadYAML(file string) error {
 				exKubeconfig := env.Expand(s.Step.Kubeconfig)
 				s.Kubeconfig = cleanPath(exKubeconfig, s.Dir)
 			}
+			s.Context = s.Step.Context
 
 			switch s.Step.KubeconfigLoading {
 			case "", harness.KubeconfigLoadingEager, harness.KubeconfigLoadingLazy: