feat/ai proxy vertex ai compatible (#3324)

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

@@ -387,6 +387,9 @@ type ProviderConfig struct {
 	// @Title zh-CN Vertex token刷新提前时间
 	// @Description zh-CN 用于Google服务账号认证，access token过期时间判定提前刷新，单位为秒，默认值为60秒
 	vertexTokenRefreshAhead int64 `required:"false" yaml:"vertexTokenRefreshAhead" json:"vertexTokenRefreshAhead"`
+	// @Title zh-CN Vertex AI OpenAI兼容模式
+	// @Description zh-CN 启用后将使用Vertex AI的OpenAI兼容API，请求和响应均使用OpenAI格式，无需协议转换。与Express Mode(apiTokens)互斥。
+	vertexOpenAICompatible bool `required:"false" yaml:"vertexOpenAICompatible" json:"vertexOpenAICompatible"`
 	// @Title zh-CN 翻译服务需指定的目标语种
 	// @Description zh-CN 翻译结果的语种，目前仅适用于DeepL服务。
 	targetLang string `required:"false" yaml:"targetLang" json:"targetLang"`
@@ -540,6 +543,7 @@ func (c *ProviderConfig) FromJson(json gjson.Result) {
 	if c.vertexTokenRefreshAhead == 0 {
 		c.vertexTokenRefreshAhead = 60
 	}
+	c.vertexOpenAICompatible = json.Get("vertexOpenAICompatible").Bool()
 	c.targetLang = json.Get("targetLang").String()
 
 	if schemaValue, ok := json.Get("responseJsonSchema").Value().(map[string]interface{}); ok {

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

@@ -21,6 +21,7 @@ import (
 	"github.com/higress-group/wasm-go/pkg/log"
 	"github.com/higress-group/wasm-go/pkg/wrapper"
 	"github.com/tidwall/gjson"
+	"github.com/tidwall/sjson"
 )
 
 const (
@@ -32,6 +33,9 @@ const (
 	// Express Mode 路径模板 (不含 project/location)
 	vertexExpressPathTemplate          = "/v1/publishers/google/models/%s:%s"
 	vertexExpressPathAnthropicTemplate = "/v1/publishers/anthropic/models/%s:%s"
+	// OpenAI-compatible endpoint 路径模板
+	// /v1beta1/projects/{PROJECT_ID}/locations/{LOCATION}/endpoints/openapi/chat/completions
+	vertexOpenAICompatiblePathTemplate = "/v1beta1/projects/%s/locations/%s/endpoints/openapi/chat/completions"
 	vertexChatCompletionAction         = "generateContent"
 	vertexChatCompletionStreamAction   = "streamGenerateContent?alt=sse"
 	vertexAnthropicMessageAction       = "rawPredict"
@@ -39,6 +43,7 @@ const (
 	vertexEmbeddingAction              = "predict"
 	vertexGlobalRegion                 = "global"
 	contextClaudeMarker                = "isClaudeRequest"
+	contextOpenAICompatibleMarker      = "isOpenAICompatibleRequest"
 	vertexAnthropicVersion             = "vertex-2023-10-16"
 )
 
@@ -47,10 +52,28 @@ type vertexProviderInitializer struct{}
 func (v *vertexProviderInitializer) ValidateConfig(config *ProviderConfig) error {
 	// Express Mode: 如果配置了 apiTokens，则使用 API Key 认证
 	if len(config.apiTokens) > 0 {
+		// Express Mode 与 OpenAI 兼容模式互斥
+		if config.vertexOpenAICompatible {
+			return errors.New("vertexOpenAICompatible is not compatible with Express Mode (apiTokens)")
+		}
 		// Express Mode 不需要其他配置
 		return nil
 	}
 
+	// OpenAI 兼容模式: 需要 OAuth 认证配置
+	if config.vertexOpenAICompatible {
+		if config.vertexAuthKey == "" {
+			return errors.New("missing vertexAuthKey in vertex provider config for OpenAI compatible mode")
+		}
+		if config.vertexRegion == "" || config.vertexProjectId == "" {
+			return errors.New("missing vertexRegion or vertexProjectId in vertex provider config for OpenAI compatible mode")
+		}
+		if config.vertexAuthServiceName == "" {
+			return errors.New("missing vertexAuthServiceName in vertex provider config for OpenAI compatible mode")
+		}
+		return nil
+	}
+
 	// 标准模式: 保持原有验证逻辑
 	if config.vertexAuthKey == "" {
 		return errors.New("missing vertexAuthKey in vertex provider config")
@@ -101,6 +124,12 @@ func (v *vertexProvider) isExpressMode() bool {
 	return len(v.config.apiTokens) > 0
 }
 
+// isOpenAICompatibleMode 检测是否启用 OpenAI 兼容模式
+// 使用 Vertex AI 的 OpenAI-compatible Chat Completions API
+func (v *vertexProvider) isOpenAICompatibleMode() bool {
+	return v.config.vertexOpenAICompatible
+}
+
 type vertexProvider struct {
 	client       wrapper.HttpClient
 	config       ProviderConfig
@@ -184,7 +213,30 @@ func (v *vertexProvider) OnRequestBody(ctx wrapper.HttpContext, apiName ApiName,
 	if v.config.IsOriginal() {
 		return types.ActionContinue, nil
 	}
+
 	headers := util.GetRequestHeaders()
+
+	// OpenAI 兼容模式: 不转换请求体，只设置路径和进行模型映射
+	if v.isOpenAICompatibleMode() {
+		ctx.SetContext(contextOpenAICompatibleMarker, true)
+		body, err := v.onOpenAICompatibleRequestBody(ctx, apiName, body, headers)
+		headers.Set("Content-Length", fmt.Sprint(len(body)))
+		util.ReplaceRequestHeaders(headers)
+		_ = proxywasm.ReplaceHttpRequestBody(body)
+		if err != nil {
+			return types.ActionContinue, err
+		}
+		// OpenAI 兼容模式需要 OAuth token
+		cached, err := v.getToken()
+		if cached {
+			return types.ActionContinue, nil
+		}
+		if err == nil {
+			return types.ActionPause, nil
+		}
+		return types.ActionContinue, err
+	}
+
 	body, err := v.TransformRequestBodyHeaders(ctx, apiName, body, headers)
 	headers.Set("Content-Length", fmt.Sprint(len(body)))
 
@@ -220,6 +272,32 @@ func (v *vertexProvider) TransformRequestBodyHeaders(ctx wrapper.HttpContext, ap
 	}
 }
 
+// onOpenAICompatibleRequestBody 处理 OpenAI 兼容模式的请求
+// 不转换请求体格式，只进行模型映射和路径设置
+func (v *vertexProvider) onOpenAICompatibleRequestBody(ctx wrapper.HttpContext, apiName ApiName, body []byte, headers http.Header) ([]byte, error) {
+	if apiName != ApiNameChatCompletion {
+		return nil, fmt.Errorf("OpenAI compatible mode only supports chat completions API")
+	}
+
+	// 解析请求进行模型映射
+	request := &chatCompletionRequest{}
+	if err := v.config.parseRequestAndMapModel(ctx, request, body); err != nil {
+		return nil, err
+	}
+
+	// 设置 OpenAI 兼容端点路径
+	path := v.getOpenAICompatibleRequestPath()
+	util.OverwriteRequestPathHeader(headers, path)
+
+	// 如果模型被映射，需要更新请求体中的模型字段
+	if request.Model != "" {
+		body, _ = sjson.SetBytes(body, "model", request.Model)
+	}
+
+	// 保持 OpenAI 格式，直接返回（可能更新了模型字段）
+	return body, nil
+}
+
 func (v *vertexProvider) onChatCompletionRequestBody(ctx wrapper.HttpContext, body []byte, headers http.Header) ([]byte, error) {
 	request := &chatCompletionRequest{}
 	err := v.config.parseRequestAndMapModel(ctx, request, body)
@@ -261,6 +339,12 @@ func (v *vertexProvider) onEmbeddingsRequestBody(ctx wrapper.HttpContext, body [
 }
 
 func (v *vertexProvider) OnStreamingResponseBody(ctx wrapper.HttpContext, name ApiName, chunk []byte, isLastChunk bool) ([]byte, error) {
+	// OpenAI 兼容模式: 透传响应，但需要解码 Unicode 转义序列
+	// Vertex AI OpenAI-compatible API 返回 ASCII-safe JSON，将非 ASCII 字符编码为 \uXXXX
+	if ctx.GetContext(contextOpenAICompatibleMarker) != nil && ctx.GetContext(contextOpenAICompatibleMarker).(bool) {
+		return util.DecodeUnicodeEscapesInSSE(chunk), nil
+	}
+
 	if ctx.GetContext(contextClaudeMarker) != nil && ctx.GetContext(contextClaudeMarker).(bool) {
 		return v.claude.OnStreamingResponseBody(ctx, name, chunk, isLastChunk)
 	}
@@ -301,6 +385,12 @@ func (v *vertexProvider) OnStreamingResponseBody(ctx wrapper.HttpContext, name A
 }
 
 func (v *vertexProvider) TransformResponseBody(ctx wrapper.HttpContext, apiName ApiName, body []byte) ([]byte, error) {
+	// OpenAI 兼容模式: 透传响应，但需要解码 Unicode 转义序列
+	// Vertex AI OpenAI-compatible API 返回 ASCII-safe JSON，将非 ASCII 字符编码为 \uXXXX
+	if ctx.GetContext(contextOpenAICompatibleMarker) != nil && ctx.GetContext(contextOpenAICompatibleMarker).(bool) {
+		return util.DecodeUnicodeEscapes(body), nil
+	}
+
 	if ctx.GetContext(contextClaudeMarker) != nil && ctx.GetContext(contextClaudeMarker).(bool) {
 		return v.claude.TransformResponseBody(ctx, apiName, body)
 	}
@@ -510,6 +600,11 @@ func (v *vertexProvider) getRequestPath(apiName ApiName, modelId string, stream
 	return path
 }
 
+// getOpenAICompatibleRequestPath 获取 OpenAI 兼容模式的请求路径
+func (v *vertexProvider) getOpenAICompatibleRequestPath() string {
+	return fmt.Sprintf(vertexOpenAICompatiblePathTemplate, v.config.vertexProjectId, v.config.vertexRegion)
+}
+
 func (v *vertexProvider) buildVertexChatRequest(request *chatCompletionRequest) *vertexChatRequest {
 	safetySettings := make([]vertexChatSafetySetting, 0)
 	for category, threshold := range v.config.geminiSafetySetting {