fix: allow for load tests to run in-cluster (#4003)

Author: RodrigoVillar

tests/fixture/tmpnet/flags/kubeconfig.go

@@ -45,10 +45,17 @@ func newKubeconfigFlagSetVars(flagSet *pflag.FlagSet, docPrefix string) *Kubecon
 }
 
 func (v *KubeconfigVars) register(stringVar varFunc[string], docPrefix string) {
+	// the default kubeConfig path is set to empty to allow for the use of a projected
+	// token when running in-cluster
+	var defaultKubeConfigPath string
+	if !tmpnet.IsRunningInCluster() {
+		defaultKubeConfigPath = os.ExpandEnv("$HOME/.kube/config")
+	}
+
 	stringVar(
 		&v.Path,
 		"kubeconfig",
-		tmpnet.GetEnvWithDefault(KubeconfigPathEnvVar, os.ExpandEnv("$HOME/.kube/config")),
+		tmpnet.GetEnvWithDefault(KubeconfigPathEnvVar, defaultKubeConfigPath),
 		docPrefix+fmt.Sprintf(
 			"The path to a kubernetes configuration file for the target cluster. Also possible to configure via the %s env variable.",
 			KubeconfigPathEnvVar,

tests/fixture/tmpnet/kube_runtime.go

@@ -145,7 +145,7 @@ func (p *KubeRuntime) GetLocalURI(ctx context.Context) (string, func(), error) {
 	}
 
 	// Use direct pod URI if running inside the cluster
-	if isRunningInCluster() {
+	if IsRunningInCluster() {
 		return p.node.URI, func() {}, nil
 	}
 
@@ -167,7 +167,7 @@ func (p *KubeRuntime) GetLocalStakingAddress(ctx context.Context) (netip.AddrPor
 	}
 
 	// Use direct pod staking address if running inside the cluster
-	if isRunningInCluster() {
+	if IsRunningInCluster() {
 		return p.node.StakingAddress, func() {}, nil
 	}
 
@@ -842,10 +842,10 @@ func configureExclusiveScheduling(template *corev1.PodTemplateSpec, labelKey str
 	}
 }
 
-// isRunningInCluster detects if this code is running inside a Kubernetes cluster
+// IsRunningInCluster detects if this code is running inside a Kubernetes cluster
 // by checking for the presence of the service account token that's automatically
 // mounted in every pod.
-func isRunningInCluster() bool {
+func IsRunningInCluster() bool {
 	_, err := os.Stat("/var/run/secrets/kubernetes.io/serviceaccount/token")
 	return err == nil
 }