feat: Support model mapping and more URL configuration formats for Azure OpenAI (#2649)

plugins/wasm-go/extensions/ai-proxy/main.go

@@ -25,6 +25,23 @@ const (
 	pluginName = "ai-proxy"
 
 	defaultMaxBodyBytes uint32 = 100 * 1024 * 1024
+
+	ctxOriginalPath = "original_path"
+	ctxOriginalHost = "original_host"
+	ctxOriginalAuth = "original_auth"
+)
+
+var (
+	headersCtxKeyMapping = map[string]string{
+		util.HeaderAuthority:     ctxOriginalHost,
+		util.HeaderPath:          ctxOriginalPath,
+		util.HeaderAuthorization: ctxOriginalAuth,
+	}
+	headerToOriginalHeaderMapping = map[string]string{
+		util.HeaderAuthority:     util.HeaderOriginalHost,
+		util.HeaderPath:          util.HeaderOriginalPath,
+		util.HeaderAuthorization: util.HeaderOriginalAuth,
+	}
 )
 
 func main() {}
@@ -75,6 +92,30 @@ func parseOverrideRuleConfig(json gjson.Result, global config.PluginConfig, plug
 	return nil
 }
 
+func initContext(ctx wrapper.HttpContext) {
+	for header, ctxKey := range headersCtxKeyMapping {
+		value, _ := proxywasm.GetHttpRequestHeader(header)
+		ctx.SetContext(ctxKey, value)
+	}
+}
+
+func saveContextsToHeaders(ctx wrapper.HttpContext) {
+	for header, ctxKey := range headersCtxKeyMapping {
+		originalValue := ctx.GetStringContext(ctxKey, "")
+		if originalValue == "" {
+			continue
+		}
+		currentValue, _ := proxywasm.GetHttpRequestHeader(header)
+		if currentValue == "" || originalValue == currentValue {
+			continue
+		}
+		originalHeader := headerToOriginalHeaderMapping[header]
+		if originalHeader != "" {
+			_ = proxywasm.ReplaceHttpRequestHeader(originalHeader, originalValue)
+		}
+	}
+}
+
 func onHttpRequestHeader(ctx wrapper.HttpContext, pluginConfig config.PluginConfig) types.Action {
 	activeProvider := pluginConfig.GetProvider()
 
@@ -86,7 +127,14 @@ func onHttpRequestHeader(ctx wrapper.HttpContext, pluginConfig config.PluginConf
 
 	log.Debugf("[onHttpRequestHeader] provider=%s", activeProvider.GetProviderType())
 
+	initContext(ctx)
+
 	rawPath := ctx.Path()
+
+	defer func() {
+		saveContextsToHeaders(ctx)
+	}()
+
 	path, _ := url.Parse(rawPath)
 	apiName := getApiName(path.Path)
 	providerConfig := pluginConfig.GetProviderConfig()
@@ -154,6 +202,10 @@ func onHttpRequestBody(ctx wrapper.HttpContext, pluginConfig config.PluginConfig
 	}
 	log.Debugf("[onHttpRequestBody] provider=%s", activeProvider.GetProviderType())
 
+	defer func() {
+		saveContextsToHeaders(ctx)
+	}()
+
 	if handler, ok := activeProvider.(provider.RequestBodyHandler); ok {
 		apiName, _ := ctx.GetContext(provider.CtxKeyApiName).(provider.ApiName)
 		providerConfig := pluginConfig.GetProviderConfig()
@@ -214,7 +266,7 @@ func onHttpResponseHeaders(ctx wrapper.HttpContext, pluginConfig config.PluginCo
 	// the apiToken is removed only when the number of consecutive request failures exceeds the threshold.
 	providerConfig.ResetApiTokenRequestFailureCount(apiTokenInUse)
 
-	headers := util.GetOriginalResponseHeaders()
+	headers := util.GetResponseHeaders()
 	if handler, ok := activeProvider.(provider.TransformResponseHeadersHandler); ok {
 		apiName, _ := ctx.GetContext(provider.CtxKeyApiName).(provider.ApiName)
 		handler.TransformResponseHeaders(ctx, apiName, headers)

plugins/wasm-go/extensions/ai-proxy/provider/azure.go

@@ -5,17 +5,33 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
+	"regexp"
 	"strings"
 
 	"github.com/alibaba/higress/plugins/wasm-go/extensions/ai-proxy/util"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
 	"github.com/higress-group/wasm-go/pkg/log"
 	"github.com/higress-group/wasm-go/pkg/wrapper"
-	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
 )
 
 const (
-	pathAzureFiles   = "/openai/files"
-	pathAzureBatches = "/openai/batches"
+	pathAzurePrefix           = "/openai"
+	pathAzureModelPlaceholder = "{model}"
+	pathAzureWithModelPrefix  = "/openai/deployments/" + pathAzureModelPlaceholder
+	queryAzureApiVersion      = "api-version"
+)
+
+var (
+	azureModelIrrelevantApis = map[ApiName]bool{
+		ApiNameModels:              true,
+		ApiNameBatches:             true,
+		ApiNameRetrieveBatch:       true,
+		ApiNameCancelBatch:         true,
+		ApiNameFiles:               true,
+		ApiNameRetrieveFile:        true,
+		ApiNameRetrieveFileContent: true,
+	}
+	regexAzureModelWithPath = regexp.MustCompile("/openai/deployments/(.+?)(/.*|$)")
 )
 
 // azureProvider is the provider for Azure OpenAI service.
@@ -23,21 +39,32 @@ type azureProviderInitializer struct {
 }
 
 func (m *azureProviderInitializer) DefaultCapabilities() map[string]string {
-	return map[string]string{
-		// TODO: azure's pattern is the same as openai, just need to handle the prefix, can be done in TransformRequestHeaders to support general capabilities
-		string(ApiNameChatCompletion): PathOpenAIChatCompletions,
-		string(ApiNameEmbeddings):     PathOpenAIEmbeddings,
-		string(ApiNameFiles):          PathOpenAIFiles,
-		string(ApiNameBatches):        PathOpenAIBatches,
+	var capabilities = map[string]string{}
+	for k, v := range (&openaiProviderInitializer{}).DefaultCapabilities() {
+		if !strings.HasPrefix(v, PathOpenAIPrefix) {
+			log.Warnf("azureProviderInitializer: capability %s has an unexpected path %s, skipping", k, v)
+			continue
+		}
+		path := strings.TrimPrefix(v, PathOpenAIPrefix)
+		if azureModelIrrelevantApis[ApiName(k)] {
+			path = pathAzurePrefix + path
+		} else {
+			path = pathAzureWithModelPrefix + path
+		}
+		capabilities[k] = path
+		log.Debugf("azureProviderInitializer: capability %s -> %s", k, path)
 	}
+	return capabilities
 }
 
 func (m *azureProviderInitializer) ValidateConfig(config *ProviderConfig) error {
 	if config.azureServiceUrl == "" {
 		return errors.New("missing azureServiceUrl in provider config")
 	}
-	if _, err := url.Parse(config.azureServiceUrl); err != nil {
+	if azureServiceUrl, err := url.Parse(config.azureServiceUrl); err != nil {
 		return fmt.Errorf("invalid azureServiceUrl: %w", err)
+	} else if !azureServiceUrl.Query().Has(queryAzureApiVersion) {
+		return fmt.Errorf("missing %s query parameter in azureServiceUrl: %s", queryAzureApiVersion, config.azureServiceUrl)
 	}
 	if config.apiTokens == nil || len(config.apiTokens) == 0 {
 		return errors.New("no apiToken found in provider config")
@@ -52,10 +79,24 @@ func (m *azureProviderInitializer) CreateProvider(config ProviderConfig) (Provid
 	} else {
 		serviceUrl = u
 	}
+
+	modelSubMatch := regexAzureModelWithPath.FindStringSubmatch(serviceUrl.Path)
+	defaultModel := "placeholder"
+	if modelSubMatch != nil {
+		defaultModel = modelSubMatch[1]
+		log.Debugf("azureProvider: found default model from serviceUrl: %s", defaultModel)
+	} else {
+		log.Debugf("azureProvider: no default model found in serviceUrl")
+	}
+
 	config.setDefaultCapabilities(m.DefaultCapabilities())
+	apiVersion := serviceUrl.Query().Get(queryAzureApiVersion)
+	log.Debugf("azureProvider: using %s: %s", queryAzureApiVersion, apiVersion)
 	return &azureProvider{
 		config:       config,
 		serviceUrl:   serviceUrl,
+		apiVersion:   apiVersion,
+		defaultModel: defaultModel,
 		contextCache: createContextCache(&config),
 	}, nil
 }
@@ -65,6 +106,8 @@ type azureProvider struct {
 
 	contextCache *contextCache
 	serviceUrl   *url.URL
+	apiVersion   string
+	defaultModel string
 }
 
 func (m *azureProvider) GetProviderType() string {
@@ -80,44 +123,68 @@ func (m *azureProvider) OnRequestBody(ctx wrapper.HttpContext, apiName ApiName,
 	return m.config.handleRequestBody(m, m.contextCache, ctx, apiName, body)
 }
 
-func (m *azureProvider) TransformRequestHeaders(ctx wrapper.HttpContext, apiName ApiName, headers http.Header) {
-	finalRequestUrl := *m.serviceUrl
-	if u, e := url.Parse(ctx.Path()); e == nil {
-		if len(u.Query()) != 0 {
-			q := m.serviceUrl.Query()
-			for k, v := range u.Query() {
-				switch len(v) {
-				case 0:
-					break
-				case 1:
-					q.Set(k, v[0])
-					break
-				default:
-					delete(q, k)
-					for _, vv := range v {
-						q.Add(k, vv)
-					}
-				}
-			}
-			finalRequestUrl.RawQuery = q.Encode()
-		}
+func (m *azureProvider) TransformRequestBody(ctx wrapper.HttpContext, apiName ApiName, body []byte) (transformedBody []byte, err error) {
+	transformedBody = body
+	err = nil
 
-		if filesIndex := strings.Index(u.Path, "/files"); filesIndex != -1 {
-			finalRequestUrl.Path = pathAzureFiles + u.Path[filesIndex+len("/files"):]
-		} else if batchesIndex := strings.Index(u.Path, "/batches"); batchesIndex != -1 {
-			finalRequestUrl.Path = pathAzureBatches + u.Path[batchesIndex+len("/batches"):]
-		}
-	} else {
-		log.Errorf("failed to parse request path: %v", e)
+	transformedBody, err = m.config.defaultTransformRequestBody(ctx, apiName, body)
+	if err != nil {
+		return
 	}
-	util.OverwriteRequestPathHeader(headers, finalRequestUrl.RequestURI())
 
+	// This must be called after the body is transformed, because it uses the model from the context filled by that call.
+	if path := m.transformRequestPath(ctx, apiName); path != "" {
+		err = util.OverwriteRequestPath(path)
+		if err == nil {
+			log.Debugf("azureProvider: overwrite request path to %s succeeded", path)
+		} else {
+			log.Errorf("azureProvider: overwrite request path to %s failed: %v", path, err)
+		}
+	}
+
+	return
+}
+
+func (m *azureProvider) transformRequestPath(ctx wrapper.HttpContext, apiName ApiName) string {
+	originalPath := util.GetOriginalRequestPath()
+
+	if m.config.IsOriginal() {
+		return originalPath
+	}
+
+	log.Debugf("azureProvider: original request path: %s", originalPath)
+	path := util.MapRequestPathByCapability(string(apiName), originalPath, m.config.capabilities)
+	log.Debugf("azureProvider: path: %s", path)
+	if strings.Contains(path, pathAzureModelPlaceholder) {
+		log.Debugf("azureProvider: path contains placeholder: %s", path)
+		model := ctx.GetStringContext(ctxKeyFinalRequestModel, "")
+		log.Debugf("azureProvider: model from context: %s", model)
+		if model == "" {
+			model = m.defaultModel
+			log.Debugf("azureProvider: use default model: %s", model)
+		}
+		path = strings.ReplaceAll(path, pathAzureModelPlaceholder, model)
+		log.Debugf("azureProvider: model replaced path: %s", path)
+	}
+	path = fmt.Sprintf("%s?%s=%s", path, queryAzureApiVersion, m.apiVersion)
+	log.Debugf("azureProvider: final path: %s", path)
+
+	return path
+}
+
+func (m *azureProvider) TransformRequestHeaders(ctx wrapper.HttpContext, apiName ApiName, headers http.Header) {
+	// We need to overwrite the request path in the request headers stage,
+	// because for some APIs, we don't read the request body and the path is model irrelevant.
+	if overwrittenPath := m.transformRequestPath(ctx, apiName); overwrittenPath != "" {
+		util.OverwriteRequestPathHeader(headers, overwrittenPath)
+	}
 	util.OverwriteRequestHostHeader(headers, m.serviceUrl.Host)
 	headers.Set("api-key", m.config.GetApiTokenInUse(ctx))
 	headers.Del("Content-Length")
 
-	if !m.config.isSupportedAPI(apiName) {
-		// If the API is not supported, we should not read the request body and keep it as it is.
+	if !m.config.isSupportedAPI(apiName) || !m.config.needToProcessRequestBody(apiName) {
+		// If the API is not supported or there is no need to process the body,
+		// we should not read the request body and keep it as it is.
 		ctx.DontReadRequestBody()
 	}
 }

plugins/wasm-go/extensions/ai-proxy/provider/provider.go

@@ -67,6 +67,7 @@ const (
 	ApiNameAnthropicComplete           ApiName = "anthropic/v1/complete"
 
 	// OpenAI
+	PathOpenAIPrefix                               = "/v1"
 	PathOpenAICompletions                          = "/v1/completions"
 	PathOpenAIChatCompletions                      = "/v1/chat/completions"
 	PathOpenAIEmbeddings                           = "/v1/embeddings"
@@ -851,7 +852,7 @@ func (c *ProviderConfig) handleRequestBody(
 	if handler, ok := provider.(TransformRequestBodyHandler); ok {
 		body, err = handler.TransformRequestBody(ctx, apiName, body)
 	} else if handler, ok := provider.(TransformRequestBodyHeadersHandler); ok {
-		headers := util.GetOriginalRequestHeaders()
+		headers := util.GetRequestHeaders()
 		body, err = handler.TransformRequestBodyHeaders(ctx, apiName, body, headers)
 		util.ReplaceRequestHeaders(headers)
 	} else {
@@ -877,7 +878,7 @@ func (c *ProviderConfig) handleRequestBody(
 }
 
 func (c *ProviderConfig) handleRequestHeaders(provider Provider, ctx wrapper.HttpContext, apiName ApiName) {
-	headers := util.GetOriginalRequestHeaders()
+	headers := util.GetRequestHeaders()
 	originPath := headers.Get(":path")
 	if c.basePath != "" && c.basePathHandling == basePathHandlingRemovePrefix {
 		headers.Set(":path", strings.TrimPrefix(originPath, c.basePath))
@@ -888,9 +889,6 @@ func (c *ProviderConfig) handleRequestHeaders(provider Provider, ctx wrapper.Htt
 	if c.basePath != "" && c.basePathHandling == basePathHandlingPrepend && !strings.HasPrefix(headers.Get(":path"), c.basePath) {
 		headers.Set(":path", path.Join(c.basePath, headers.Get(":path")))
 	}
-	if headers.Get(":path") != originPath {
-		headers.Set("X-ENVOY-ORIGINAL-PATH", originPath)
-	}
 	util.ReplaceRequestHeaders(headers)
 }
 
@@ -908,7 +906,9 @@ func (c *ProviderConfig) defaultTransformRequestBody(ctx wrapper.HttpContext, ap
 	}
 	model := gjson.GetBytes(body, "model").String()
 	ctx.SetContext(ctxKeyOriginalRequestModel, model)
-	return sjson.SetBytes(body, "model", getMappedModel(model, c.modelMapping))
+	mappedModel := getMappedModel(model, c.modelMapping)
+	ctx.SetContext(ctxKeyFinalRequestModel, mappedModel)
+	return sjson.SetBytes(body, "model", mappedModel)
 }
 
 func (c *ProviderConfig) DefaultTransformResponseHeaders(ctx wrapper.HttpContext, headers http.Header) {

plugins/wasm-go/extensions/ai-proxy/provider/vertex.go

@@ -15,10 +15,10 @@ import (
 	"time"
 
 	"github.com/alibaba/higress/plugins/wasm-go/extensions/ai-proxy/util"
-	"github.com/higress-group/wasm-go/pkg/log"
-	"github.com/higress-group/wasm-go/pkg/wrapper"
 	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
 	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
+	"github.com/higress-group/wasm-go/pkg/log"
+	"github.com/higress-group/wasm-go/pkg/wrapper"
 	"github.com/tidwall/gjson"
 )
 
@@ -136,7 +136,7 @@ func (v *vertexProvider) OnRequestBody(ctx wrapper.HttpContext, apiName ApiName,
 	if v.config.IsOriginal() {
 		return types.ActionContinue, nil
 	}
-	headers := util.GetOriginalRequestHeaders()
+	headers := util.GetRequestHeaders()
 	body, err := v.TransformRequestBodyHeaders(ctx, apiName, body, headers)
 	util.ReplaceRequestHeaders(headers)
 	_ = proxywasm.ReplaceHttpRequestBody(body)

plugins/wasm-go/extensions/ai-proxy/util/http.go

@@ -10,7 +10,14 @@ import (
 )
 
 const (
-	HeaderContentType = "Content-Type"
+	HeaderContentType   = "Content-Type"
+	HeaderPath          = ":path"
+	HeaderAuthority     = ":authority"
+	HeaderAuthorization = "Authorization"
+
+	HeaderOriginalPath = "X-ENVOY-ORIGINAL-PATH"
+	HeaderOriginalHost = "X-ENVOY-ORIGINAL-HOST"
+	HeaderOriginalAuth = "X-HI-ORIGINAL-AUTH"
 
 	MimeTypeTextPlain       = "text/plain"
 	MimeTypeApplicationJson = "application/json"
@@ -48,49 +55,49 @@ func CreateHeaders(kvs ...string) [][2]string {
 }
 
 func OverwriteRequestPath(path string) error {
-	if originPath, err := proxywasm.GetHttpRequestHeader(":path"); err == nil {
-		_ = proxywasm.ReplaceHttpRequestHeader("X-ENVOY-ORIGINAL-PATH", originPath)
-	}
-	return proxywasm.ReplaceHttpRequestHeader(":path", path)
+	return proxywasm.ReplaceHttpRequestHeader(HeaderPath, path)
 }
 
 func OverwriteRequestAuthorization(credential string) error {
-	if exist, _ := proxywasm.GetHttpRequestHeader("X-HI-ORIGINAL-AUTH"); exist == "" {
-		if originAuth, err := proxywasm.GetHttpRequestHeader("Authorization"); err == nil {
-			_ = proxywasm.AddHttpRequestHeader("X-HI-ORIGINAL-AUTH", originAuth)
+	if exist, _ := proxywasm.GetHttpRequestHeader(HeaderOriginalAuth); exist == "" {
+		if originAuth, err := proxywasm.GetHttpRequestHeader(HeaderAuthorization); err == nil {
+			_ = proxywasm.AddHttpRequestHeader(HeaderOriginalPath, originAuth)
 		}
 	}
-	return proxywasm.ReplaceHttpRequestHeader("Authorization", credential)
+	return proxywasm.ReplaceHttpRequestHeader(HeaderAuthorization, credential)
 }
 
 func OverwriteRequestHostHeader(headers http.Header, host string) {
-	if originHost, err := proxywasm.GetHttpRequestHeader(":authority"); err == nil {
-		headers.Set("X-ENVOY-ORIGINAL-HOST", originHost)
+	if originHost, err := proxywasm.GetHttpRequestHeader(HeaderAuthority); err == nil {
+		headers.Set(HeaderOriginalHost, originHost)
 	}
-	headers.Set(":authority", host)
+	headers.Set(HeaderAuthority, host)
 }
 
 func OverwriteRequestPathHeader(headers http.Header, path string) {
-	if originPath, err := proxywasm.GetHttpRequestHeader(":path"); err == nil {
-		headers.Set("X-ENVOY-ORIGINAL-PATH", originPath)
-	}
-	headers.Set(":path", path)
+	headers.Set(HeaderPath, path)
 }
 
 func OverwriteRequestPathHeaderByCapability(headers http.Header, apiName string, mapping map[string]string) {
-	mappedPath, exist := mapping[apiName]
-	if !exist {
+	originPath := GetOriginalRequestPath()
+	mappedPath := MapRequestPathByCapability(apiName, originPath, mapping)
+	if mappedPath == "" {
 		return
 	}
-	originPath, err := proxywasm.GetHttpRequestHeader(":path")
-	if err == nil {
-		headers.Set("X-ENVOY-ORIGINAL-PATH", originPath)
-	}
+	headers.Set(HeaderPath, mappedPath)
+	log.Debugf("[OverwriteRequestPath] originPath=%s, mappedPath=%s", originPath, mappedPath)
+}
+
+func MapRequestPathByCapability(apiName string, originPath string, mapping map[string]string) string {
 	/**
 	这里实现不太优雅，理应通过 apiName 来判断使用哪个正则替换
 	但 ApiName 定义在 provider 中， 而 provider 中又引用了 util
 	会导致循环引用
 	**/
+	mappedPath, exist := mapping[apiName]
+	if !exist {
+		return ""
+	}
 	if strings.Contains(mappedPath, "{") && strings.Contains(mappedPath, "}") {
 		replacements := []struct {
 			regx *regexp.Regexp
@@ -119,17 +126,61 @@ func OverwriteRequestPathHeaderByCapability(headers http.Header, apiName string,
 			}
 		}
 	}
-	headers.Set(":path", mappedPath)
-	log.Debugf("[OverwriteRequestPath] originPath=%s, mappedPath=%s", originPath, mappedPath)
+	return mappedPath
+}
+
+func GetOriginalRequestPath() string {
+	path, err := proxywasm.GetHttpRequestHeader(HeaderOriginalPath)
+	if path != "" && err == nil {
+		return path
+	}
+	if path, err = proxywasm.GetHttpRequestHeader(HeaderPath); err == nil {
+		return path
+	}
+	return ""
+}
+
+func SetOriginalRequestPath(path string) {
+	_ = proxywasm.ReplaceHttpRequestHeader(HeaderOriginalPath, path)
+}
+
+func GetOriginalRequestHost() string {
+	host, err := proxywasm.GetHttpRequestHeader(HeaderOriginalHost)
+	if host != "" && err == nil {
+		return host
+	}
+	if host, err = proxywasm.GetHttpRequestHeader(HeaderAuthority); err == nil {
+		return host
+	}
+	return ""
+}
+
+func SetOriginalRequestHost(host string) {
+	_ = proxywasm.ReplaceHttpRequestHeader(HeaderOriginalHost, host)
+}
+
+func GetOriginalRequestAuth() string {
+	auth, err := proxywasm.GetHttpRequestHeader(HeaderOriginalAuth)
+	if auth != "" && err == nil {
+		return auth
+	}
+	if auth, err = proxywasm.GetHttpRequestHeader(HeaderAuthorization); err == nil {
+		return auth
+	}
+	return ""
+}
+
+func SetOriginalRequestAuth(auth string) {
+	_ = proxywasm.ReplaceHttpRequestHeader(HeaderOriginalAuth, auth)
 }
 
 func OverwriteRequestAuthorizationHeader(headers http.Header, credential string) {
-	if exist := headers.Get("X-HI-ORIGINAL-AUTH"); exist == "" {
-		if originAuth := headers.Get("Authorization"); originAuth != "" {
-			headers.Set("X-HI-ORIGINAL-AUTH", originAuth)
+	if exist := headers.Get(HeaderOriginalAuth); exist == "" {
+		if originAuth := headers.Get(HeaderAuthorization); originAuth != "" {
+			headers.Set(HeaderOriginalAuth, originAuth)
 		}
 	}
-	headers.Set("Authorization", credential)
+	headers.Set(HeaderAuthorization, credential)
 }
 
 func HeaderToSlice(header http.Header) [][2]string {
@@ -152,22 +203,22 @@ func SliceToHeader(slice [][2]string) http.Header {
 	return header
 }
 
-func GetOriginalRequestHeaders() http.Header {
-	originalHeaders, _ := proxywasm.GetHttpRequestHeaders()
-	return SliceToHeader(originalHeaders)
+func GetRequestHeaders() http.Header {
+	header, _ := proxywasm.GetHttpRequestHeaders()
+	return SliceToHeader(header)
 }
 
-func GetOriginalResponseHeaders() http.Header {
-	originalHeaders, _ := proxywasm.GetHttpResponseHeaders()
-	return SliceToHeader(originalHeaders)
+func GetResponseHeaders() http.Header {
+	headers, _ := proxywasm.GetHttpResponseHeaders()
+	return SliceToHeader(headers)
 }
 
 func ReplaceRequestHeaders(headers http.Header) {
-	modifiedHeaders := HeaderToSlice(headers)
-	_ = proxywasm.ReplaceHttpRequestHeaders(modifiedHeaders)
+	headerSlice := HeaderToSlice(headers)
+	_ = proxywasm.ReplaceHttpRequestHeaders(headerSlice)
 }
 
 func ReplaceResponseHeaders(headers http.Header) {
-	modifiedHeaders := HeaderToSlice(headers)
-	_ = proxywasm.ReplaceHttpResponseHeaders(modifiedHeaders)
+	headerSlice := HeaderToSlice(headers)
+	_ = proxywasm.ReplaceHttpResponseHeaders(headerSlice)
 }