feat: support stepfun model (#1012)

Co-authored-by: Kent Dong <kentstl@163.com>

plugins/wasm-go/extensions/ai-proxy/README.md

@@ -19,9 +19,10 @@ description: AI 代理插件配置参考
 
 `provider`的配置字段说明如下：
 
+
 | 名称           | 数据类型        | 填写要求 | 默认值 | 描述                                                         |
 | -------------- | --------------- | -------- | ------ | ------------------------------------------------------------ |
-| `type`         | string          | 必填     | -      | AI 服务提供商名称。目前支持以下取值：openai, azure, moonshot, qwen, zhipuai, baidu, minimax |
+| `type`         | string          | 必填     | -      | AI 服务提供商名称 |
 | `apiTokens`    | array of string | 必填     | -      | 用于在访问 AI 服务时进行认证的令牌。如果配置了多个 token，插件会在请求时随机进行选择。部分服务提供商只支持配置一个 token。 |
 | `timeout`      | number          | 非必填   | -      | 访问 AI 服务的超时时间。单位为毫秒。默认值为 120000，即 2 分钟 |
 | `modelMapping` | map of string   | 非必填   | -      | AI 模型映射表，用于将请求中的模型名称映射为服务提供商支持模型名称。<br/>可以使用 "*" 为键来配置通用兜底映射关系 |
@@ -127,6 +128,9 @@ Ollama 所对应的 `type` 为 `ollama`。它特有的配置字段如下：
 | `hunyuanAuthId` | string | 必填   | -   | 混元用于v3版本认证的id |
 | `hunyuanAuthKey` | string | 必填   | -   | 混元用于v3版本认证的key |
 
+#### 阶跃星辰 (Stepfun)
+
+阶跃星辰所对应的 `type` 为 `stepfun`。它并无特有的配置字段。
 
 ## 用法示例
 

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

@@ -27,6 +27,7 @@ const (
 	providerTypeOllama   = "ollama"
 	providerTypeBaidu    = "baidu"
 	providerTypeHunyuan  = "hunyuan"
+	providerTypeStepfun  = "stepfun"
 	providerTypeMinimax  = "minimax"
 
 	protocolOpenAI   = "openai"
@@ -74,6 +75,7 @@ var (
 		providerTypeOllama:   &ollamaProviderInitializer{},
 		providerTypeBaidu:    &baiduProviderInitializer{},
 		providerTypeHunyuan:  &hunyuanProviderInitializer{},
+		providerTypeStepfun:  &stepfunProviderInitializer{},
 		providerTypeMinimax:  &minimaxProviderInitializer{},
 	}
 )
@@ -104,7 +106,7 @@ type ResponseBodyHandler interface {
 
 type ProviderConfig struct {
 	// @Title zh-CN AI服务提供商
-	// @Description zh-CN AI服务提供商类型，目前支持的取值为："moonshot"、"qwen"、"openai"、"azure"、"baichuan"、"yi"、"zhipuai"、"ollama"、"baidu"、minimax"
+	// @Description zh-CN AI服务提供商类型
 	typ string `required:"true" yaml:"type" json:"type"`
 	// @Title zh-CN API Tokens
 	// @Description zh-CN 在请求AI服务时用于认证的API Token列表。不同的AI服务提供商可能有不同的名称。部分供应商只支持配置一个API Token（如Azure OpenAI）。

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

@@ -0,0 +1,85 @@
+package provider
+
+import (
+	"fmt"
+
+	"github.com/alibaba/higress/plugins/wasm-go/extensions/ai-proxy/util"
+	"github.com/alibaba/higress/plugins/wasm-go/pkg/wrapper"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
+	"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
+)
+
+const (
+	stepfunDomain             = "api.stepfun.com"
+	stepfunChatCompletionPath = "/v1/chat/completions"
+)
+
+type stepfunProviderInitializer struct {
+}
+
+func (m *stepfunProviderInitializer) ValidateConfig(config ProviderConfig) error {
+	return nil
+}
+
+func (m *stepfunProviderInitializer) CreateProvider(config ProviderConfig) (Provider, error) {
+	return &stepfunProvider{
+		config:       config,
+		contextCache: createContextCache(&config),
+	}, nil
+}
+
+type stepfunProvider struct {
+	config       ProviderConfig
+	contextCache *contextCache
+}
+
+func (m *stepfunProvider) GetProviderType() string {
+	return providerTypeStepfun
+}
+
+func (m *stepfunProvider) OnRequestHeaders(ctx wrapper.HttpContext, apiName ApiName, log wrapper.Log) (types.Action, error) {
+	if apiName != ApiNameChatCompletion {
+		return types.ActionContinue, errUnsupportedApiName
+	}
+	_ = util.OverwriteRequestPath(stepfunChatCompletionPath)
+	_ = util.OverwriteRequestHost(stepfunDomain)
+	_ = proxywasm.ReplaceHttpRequestHeader("Authorization", "Bearer "+m.config.GetRandomToken())
+
+	if m.contextCache == nil {
+		ctx.DontReadRequestBody()
+	} else {
+		_ = proxywasm.RemoveHttpRequestHeader("Content-Length")
+	}
+
+	return types.ActionContinue, nil
+}
+
+func (m *stepfunProvider) OnRequestBody(ctx wrapper.HttpContext, apiName ApiName, body []byte, log wrapper.Log) (types.Action, error) {
+	if apiName != ApiNameChatCompletion {
+		return types.ActionContinue, errUnsupportedApiName
+	}
+	if m.contextCache == nil {
+		return types.ActionContinue, nil
+	}
+	request := &chatCompletionRequest{}
+	if err := decodeChatCompletionRequest(body, request); err != nil {
+		return types.ActionContinue, err
+	}
+	err := m.contextCache.GetContent(func(content string, err error) {
+		defer func() {
+			_ = proxywasm.ResumeHttpRequest()
+		}()
+		if err != nil {
+			log.Errorf("failed to load context file: %v", err)
+			_ = util.SendResponse(500, util.MimeTypeTextPlain, fmt.Sprintf("failed to load context file: %v", err))
+		}
+		insertContextMessage(request, content)
+		if err := replaceJsonRequestBody(request, log); err != nil {
+			_ = util.SendResponse(500, util.MimeTypeTextPlain, fmt.Sprintf("failed to replace request body: %v", err))
+		}
+	}, log)
+	if err == nil {
+		return types.ActionPause, nil
+	}
+	return types.ActionContinue, err
+}