use case-insensitive header keys for http probes

Kubernetes-commit: 23b09f8d26cb6f7a9375c6d3bf23ffcc21dcbc62

Author: dddddai

core/v1/generated.proto

@@ -2137,7 +2137,8 @@ type SecretEnvSource struct {
 
 // HTTPHeader describes a custom header to be used in HTTP probes
 type HTTPHeader struct {
-	// The header field name
+	// The header field name.
+	// This will be canonicalized upon output, so case-variant names will be understood as the same header.
 	Name string `json:"name" protobuf:"bytes,1,opt,name=name"`
 	// The header field value
 	Value string `json:"value" protobuf:"bytes,2,opt,name=value"`

core/v1/types.go

@@ -818,7 +818,7 @@ func (HTTPGetAction) SwaggerDoc() map[string]string {
 
 var map_HTTPHeader = map[string]string{
 	"":      "HTTPHeader describes a custom header to be used in HTTP probes",
-	"name":  "The header field name",
+	"name":  "The header field name. This will be canonicalized upon output, so case-variant names will be understood as the same header.",
 	"value": "The header field value",
 }