test: allow running functional tests for different k8s versions

test/integration/functional_test.go

@@ -42,6 +42,7 @@ import (
 
 	"k8s.io/minikube/pkg/drivers/kic/oci"
 	"k8s.io/minikube/pkg/minikube/config"
+	"k8s.io/minikube/pkg/minikube/constants"
 	"k8s.io/minikube/pkg/minikube/detect"
 	"k8s.io/minikube/pkg/minikube/localpath"
 	"k8s.io/minikube/pkg/minikube/reason"
@@ -70,9 +71,39 @@ var mitm *StartSession
 
 var runCorpProxy = detect.GithubActionRunner() && runtime.GOOS == "linux" && !arm64Platform()
 
+// versionStrings stores the version number which we want to run test on
+var versionStrings = []string{
+	"",
+	constants.NewestKubernetesVersion,
+}
+
+var overrideVersionString = ""
+
 // TestFunctional are functionality tests which can safely share a profile in parallel
 func TestFunctional(t *testing.T) {
 
+	// if --kubernetes-version has been specified then we will respect the version
+	if strings.Contains(*startArgs, "--kubernetes-version") {
+		versionStrings = []string{""}
+	}
+
+	// when the version is "" (default), test will be named something like "TestFunctional/parallel/xxx"
+	// but when the version is specified, test will be named something like TestFunctional/Versionxxx/parallel/xxx
+	// by doing so, when user want to run a functional test on an existing minikube cluster, it can still use
+	// -test.run TestFunctional/parallel/MountCmd without triggering multiple functional tests for different versions
+	for _, versionString := range versionStrings {
+		overrideVersionString = versionString
+		if versionString != "" {
+			t.Run("Version"+versionString, func(t *testing.T) {
+				testFunctional(t)
+			})
+		} else {
+			testFunctional(t)
+		}
+	}
+}
+
+func testFunctional(t *testing.T) {
 	profile := UniqueProfileName("functional")
 	ctx, cancel := context.WithTimeout(context.Background(), Minutes(40))
 	defer func() {
@@ -86,7 +117,6 @@ func TestFunctional(t *testing.T) {
 
 		Cleanup(t, profile, cancel)
 	}()
-
 	// Serial tests
 	t.Run("serial", func(t *testing.T) {
 		tests := []struct {

test/integration/main_test.go

@@ -116,7 +116,11 @@ func setMaxParallelism() {
 
 // StartArgs returns the arguments normally used for starting minikube
 func StartArgs() []string {
-	return strings.Split(*startArgs, " ")
+	res := strings.Split(*startArgs, " ")
+	if overrideVersionString != "" {
+		res = append(res, fmt.Sprintf("--kubernetes-version=%s", overrideVersionString))
+	}
+	return res
 }
 
 // Target returns where the minikube binary can be found