Add GetAllHeaders method to golang HTTP filter (#33821)

Signed-off-by: Willem Veerman <6502426+willemveerman@users.noreply.github.com>

contrib/golang/common/go/api/type.go

@@ -131,6 +131,9 @@ type HeaderMap interface {
 
 	// RangeWithCopy calls f sequentially for each key and value copied from the map.
 	RangeWithCopy(f func(key, value string) bool)
+
+	// GetAllHeaders returns all the headers.
+	GetAllHeaders() map[string][]string
 }
 
 type RequestHeaderMap interface {

contrib/golang/filters/http/source/go/pkg/http/type.go

@@ -155,6 +155,18 @@ func (h *requestOrResponseHeaderMapImpl) RangeWithCopy(f func(key, value string)
 	}
 }
 
+func (h *requestOrResponseHeaderMapImpl) GetAllHeaders() map[string][]string {
+	h.mutex.Lock()
+	defer h.mutex.Unlock()
+	h.initHeaders()
+	copiedHeaders := make(map[string][]string)
+	for key, value := range h.headers {
+		copiedHeaders[key] = make([]string, len(value))
+		copy(copiedHeaders[key], value)
+	}
+	return copiedHeaders
+}
+
 // api.RequestHeaderMap
 type requestHeaderMapImpl struct {
 	requestOrResponseHeaderMapImpl
@@ -318,6 +330,18 @@ func (h *requestOrResponseTrailerMapImpl) RangeWithCopy(f func(key, value string
 	}
 }
 
+func (h *requestOrResponseTrailerMapImpl) GetAllHeaders() map[string][]string {
+	h.mutex.Lock()
+	defer h.mutex.Unlock()
+	h.initTrailers()
+	copiedHeaders := make(map[string][]string)
+	for key, value := range h.headers {
+		copiedHeaders[key] = make([]string, len(value))
+		copy(copiedHeaders[key], value)
+	}
+	return copiedHeaders
+}
+
 // api.RequestTrailerMap
 type requestTrailerMapImpl struct {
 	requestOrResponseTrailerMapImpl

contrib/golang/filters/http/test/test_data/basic/filter.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"net/url"
+	"reflect"
 	"strconv"
 	"strings"
 	"time"
@@ -20,6 +21,7 @@ type filter struct {
 	method          string
 	path            string
 	host            string
+	all_headers     map[string][]string
 
 	// for bad api call testing
 	header api.RequestHeaderMap
@@ -181,6 +183,31 @@ func (f *filter) decodeHeaders(header api.RequestHeaderMap, endStream bool) api.
 		return true
 	})
 
+	test_header_key := "test-header-copy"
+
+	old_value := "old-value"
+
+	header.Set(test_header_key, old_value)
+
+	f.all_headers = make(map[string][]string)
+
+	header.RangeWithCopy(func(key, value string) bool {
+		f.all_headers[key] = append(f.all_headers[key], value)
+		return true
+	})
+
+	header_map := header.GetAllHeaders()
+
+	if !reflect.DeepEqual(f.all_headers, header_map) {
+		return f.fail("GetAllHeaders returned incorrect data, expected:\n%v\n got:\n%v", f.all_headers, header_map)
+	}
+
+	header.Set(test_header_key, "new-value")
+
+	if !reflect.DeepEqual(header_map[test_header_key], []string{old_value}) {
+		return f.fail("GetAllHeaders output changed - expected '%v', got '%v'", []string{old_value}, header_map[test_header_key])
+	}
+
 	origin, found := header.Get("x-test-header-0")
 	hdrs := header.Values("x-test-header-0")
 	if found {