Merge pull request #59495 from ericchiang/client-auth-exec

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

 client-go: add an exec-based client auth provider

Updates https://github.com/kubernetes/features/issues/541
Implements https://github.com/kubernetes/community/pull/1503
Closes https://github.com/kubernetes/kubernetes/issues/57164

```release-note
client-go: alpha support for exec-based credential providers
```

/sig auth
/kind feature

Kubernetes-commit: cb9d6b51556a1677f262e35e4aded0051c424818

vendor/k8s.io/client-go/tools/clientcmd/api/zz_generated.deepcopy.go

@@ -63,6 +63,15 @@ func (in *AuthInfo) DeepCopyInto(out *AuthInfo) {
 			(*in).DeepCopyInto(*out)
 		}
 	}
+	if in.Exec != nil {
+		in, out := &in.Exec, &out.Exec
+		if *in == nil {
+			*out = nil
+		} else {
+			*out = new(ExecConfig)
+			(*in).DeepCopyInto(*out)
+		}
+	}
 	if in.Extensions != nil {
 		in, out := &in.Extensions, &out.Extensions
 		*out = make(map[string]runtime.Object, len(*in))
@@ -241,6 +250,48 @@ func (in *Context) DeepCopy() *Context {
 	return out
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *ExecConfig) DeepCopyInto(out *ExecConfig) {
+	*out = *in
+	if in.Args != nil {
+		in, out := &in.Args, &out.Args
+		*out = make([]string, len(*in))
+		copy(*out, *in)
+	}
+	if in.Env != nil {
+		in, out := &in.Env, &out.Env
+		*out = make([]ExecEnvVar, len(*in))
+		copy(*out, *in)
+	}
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ExecConfig.
+func (in *ExecConfig) DeepCopy() *ExecConfig {
+	if in == nil {
+		return nil
+	}
+	out := new(ExecConfig)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *ExecEnvVar) DeepCopyInto(out *ExecEnvVar) {
+	*out = *in
+	return
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new ExecEnvVar.
+func (in *ExecEnvVar) DeepCopy() *ExecEnvVar {
+	if in == nil {
+		return nil
+	}
+	out := new(ExecEnvVar)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *Preferences) DeepCopyInto(out *Preferences) {
 	*out = *in