Automated cherry pick of #117182: use case-insensitive header keys for http probes

api/openapi-spec/v3/api__v1_openapi.json

@@ -2566,7 +2566,7 @@
         "properties": {
           "name": {
             "default": "",
-            "description": "The header field name",
+            "description": "The header field name. This will be canonicalized upon output, so case-variant names will be understood as the same header.",
             "type": "string"
           },
           "value": {

api/openapi-spec/v3/apis__apps__v1_openapi.json

@@ -2522,7 +2522,7 @@
         "properties": {
           "name": {
             "default": "",
-            "description": "The header field name",
+            "description": "The header field name. This will be canonicalized upon output, so case-variant names will be understood as the same header.",
             "type": "string"
           },
           "value": {

api/openapi-spec/v3/apis__batch__v1_openapi.json

@@ -1813,7 +1813,7 @@
         "properties": {
           "name": {
             "default": "",
-            "description": "The header field name",
+            "description": "The header field name. This will be canonicalized upon output, so case-variant names will be understood as the same header.",
             "type": "string"
           },
           "value": {

pkg/apis/core/types.go

@@ -2037,7 +2037,8 @@ 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
 	// The header field value
 	Value string

pkg/probe/http/request.go

@@ -113,7 +113,7 @@ func formatURL(scheme string, host string, port int, path string) *url.URL {
 func v1HeaderToHTTPHeader(headerList []v1.HTTPHeader) http.Header {
 	headers := make(http.Header)
 	for _, header := range headerList {
-		headers[header.Name] = append(headers[header.Name], header.Value)
+		headers.Add(header.Name, header.Value)
 	}
 	return headers
 }

pkg/probe/http/request_test.go

@@ -16,7 +16,13 @@ limitations under the License.
 
 package http
 
-import "testing"
+import (
+	"net/http"
+	"reflect"
+	"testing"
+
+	v1 "k8s.io/api/core/v1"
+)
 
 func TestFormatURL(t *testing.T) {
 	testCases := []struct {
@@ -38,3 +44,48 @@ func TestFormatURL(t *testing.T) {
 		}
 	}
 }
+
+func Test_v1HeaderToHTTPHeader(t *testing.T) {
+	tests := []struct {
+		name       string
+		headerList []v1.HTTPHeader
+		want       http.Header
+	}{
+		{
+			name: "not empty input",
+			headerList: []v1.HTTPHeader{
+				{Name: "Connection", Value: "Keep-Alive"},
+				{Name: "Content-Type", Value: "text/html"},
+				{Name: "Accept-Ranges", Value: "bytes"},
+			},
+			want: http.Header{
+				"Connection":    {"Keep-Alive"},
+				"Content-Type":  {"text/html"},
+				"Accept-Ranges": {"bytes"},
+			},
+		},
+		{
+			name: "case insensitive",
+			headerList: []v1.HTTPHeader{
+				{Name: "HOST", Value: "example.com"},
+				{Name: "FOO-bAR", Value: "value"},
+			},
+			want: http.Header{
+				"Host":    {"example.com"},
+				"Foo-Bar": {"value"},
+			},
+		},
+		{
+			name:       "empty input",
+			headerList: []v1.HTTPHeader{},
+			want:       http.Header{},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := v1HeaderToHTTPHeader(tt.headerList); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("v1HeaderToHTTPHeader() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

staging/src/k8s.io/api/core/v1/types.go

@@ -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"`