feat: add Proxy channel type and relay mode (#1678)

Add the Proxy channel type and relay mode to support proxying requests to custom upstream services.

relay/adaptor.go

@@ -15,6 +15,7 @@ import (
 	"github.com/songquanpeng/one-api/relay/adaptor/ollama"
 	"github.com/songquanpeng/one-api/relay/adaptor/openai"
 	"github.com/songquanpeng/one-api/relay/adaptor/palm"
+	"github.com/songquanpeng/one-api/relay/adaptor/proxy"
 	"github.com/songquanpeng/one-api/relay/adaptor/tencent"
 	"github.com/songquanpeng/one-api/relay/adaptor/vertexai"
 	"github.com/songquanpeng/one-api/relay/adaptor/xunfei"
@@ -58,6 +59,8 @@ func GetAdaptor(apiType int) adaptor.Adaptor {
 		return &deepl.Adaptor{}
 	case apitype.VertexAI:
 		return &vertexai.Adaptor{}
+	case apitype.Proxy:
+		return &proxy.Adaptor{}
 	}
 	return nil
 }

relay/adaptor/proxy/adaptor.go

@@ -0,0 +1,89 @@
+package proxy
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"github.com/pkg/errors"
+	"github.com/songquanpeng/one-api/relay/adaptor"
+	channelhelper "github.com/songquanpeng/one-api/relay/adaptor"
+	"github.com/songquanpeng/one-api/relay/meta"
+	"github.com/songquanpeng/one-api/relay/model"
+	relaymodel "github.com/songquanpeng/one-api/relay/model"
+)
+
+var _ adaptor.Adaptor = new(Adaptor)
+
+const channelName = "proxy"
+
+type Adaptor struct{}
+
+func (a *Adaptor) Init(meta *meta.Meta) {
+}
+
+func (a *Adaptor) ConvertRequest(c *gin.Context, relayMode int, request *model.GeneralOpenAIRequest) (any, error) {
+	return nil, errors.New("notimplement")
+}
+
+func (a *Adaptor) DoResponse(c *gin.Context, resp *http.Response, meta *meta.Meta) (usage *model.Usage, err *model.ErrorWithStatusCode) {
+	for k, v := range resp.Header {
+		for _, vv := range v {
+			c.Writer.Header().Set(k, vv)
+		}
+	}
+
+	c.Writer.WriteHeader(resp.StatusCode)
+	if _, gerr := io.Copy(c.Writer, resp.Body); gerr != nil {
+		return nil, &relaymodel.ErrorWithStatusCode{
+			StatusCode: http.StatusInternalServerError,
+			Error: relaymodel.Error{
+				Message: gerr.Error(),
+			},
+		}
+	}
+
+	return nil, nil
+}
+
+func (a *Adaptor) GetModelList() (models []string) {
+	return nil
+}
+
+func (a *Adaptor) GetChannelName() string {
+	return channelName
+}
+
+// GetRequestURL remove static prefix, and return the real request url to the upstream service
+func (a *Adaptor) GetRequestURL(meta *meta.Meta) (string, error) {
+	prefix := fmt.Sprintf("/v1/oneapi/proxy/%d", meta.ChannelId)
+	return meta.BaseURL + strings.TrimPrefix(meta.RequestURLPath, prefix), nil
+
+}
+
+func (a *Adaptor) SetupRequestHeader(c *gin.Context, req *http.Request, meta *meta.Meta) error {
+	for k, v := range c.Request.Header {
+		req.Header.Set(k, v[0])
+	}
+
+	// remove unnecessary headers
+	req.Header.Del("Host")
+	req.Header.Del("Content-Length")
+	req.Header.Del("Accept-Encoding")
+	req.Header.Del("Connection")
+
+	// set authorization header
+	req.Header.Set("Authorization", meta.APIKey)
+
+	return nil
+}
+
+func (a *Adaptor) ConvertImageRequest(request *model.ImageRequest) (any, error) {
+	return nil, errors.Errorf("not implement")
+}
+
+func (a *Adaptor) DoRequest(c *gin.Context, meta *meta.Meta, requestBody io.Reader) (*http.Response, error) {
+	return channelhelper.DoRequestHelper(a, c, meta, requestBody)
+}

relay/apitype/define.go

@@ -18,6 +18,7 @@ const (
 	Cloudflare
 	DeepL
 	VertexAI
+	Proxy
 
 	Dummy // this one is only for count, do not add any channel after this
 )

relay/channeltype/define.go

@@ -44,5 +44,6 @@ const (
 	Doubao
 	Novita
 	VertextAI
+	Proxy
 	Dummy
 )

relay/channeltype/helper.go

@@ -37,6 +37,8 @@ func ToAPIType(channelType int) int {
 		apiType = apitype.DeepL
 	case VertextAI:
 		apiType = apitype.VertexAI
+	case Proxy:
+		apiType = apitype.Proxy
 	}
 
 	return apiType

relay/channeltype/url.go

@@ -44,6 +44,7 @@ var ChannelBaseURLs = []string{
 	"https://ark.cn-beijing.volces.com",         // 40
 	"https://api.novita.ai/v3/openai",           // 41
 	"",                                          // 42
+	"",                                          // 43
 }
 
 func init() {

relay/controller/proxy.go

@@ -0,0 +1,41 @@
+// Package controller is a package for handling the relay controller
+package controller
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/songquanpeng/one-api/common/logger"
+	"github.com/songquanpeng/one-api/relay"
+	"github.com/songquanpeng/one-api/relay/adaptor/openai"
+	"github.com/songquanpeng/one-api/relay/meta"
+	relaymodel "github.com/songquanpeng/one-api/relay/model"
+)
+
+// RelayProxyHelper is a helper function to proxy the request to the upstream service
+func RelayProxyHelper(c *gin.Context, relayMode int) *relaymodel.ErrorWithStatusCode {
+	ctx := c.Request.Context()
+	meta := meta.GetByContext(c)
+
+	adaptor := relay.GetAdaptor(meta.APIType)
+	if adaptor == nil {
+		return openai.ErrorWrapper(fmt.Errorf("invalid api type: %d", meta.APIType), "invalid_api_type", http.StatusBadRequest)
+	}
+	adaptor.Init(meta)
+
+	resp, err := adaptor.DoRequest(c, meta, c.Request.Body)
+	if err != nil {
+		logger.Errorf(ctx, "DoRequest failed: %s", err.Error())
+		return openai.ErrorWrapper(err, "do_request_failed", http.StatusInternalServerError)
+	}
+
+	// do response
+	_, respErr := adaptor.DoResponse(c, resp, meta)
+	if respErr != nil {
+		logger.Errorf(ctx, "respErr is not nil: %+v", respErr)
+		return respErr
+	}
+
+	return nil
+}

relay/meta/relay_meta.go

@@ -18,11 +18,12 @@ type Meta struct {
 	UserId       int
 	Group        string
 	ModelMapping map[string]string
-	BaseURL      string
-	APIKey       string
-	APIType      int
-	Config       model.ChannelConfig
-	IsStream     bool
+	// BaseURL is the proxy url set in the channel config
+	BaseURL  string
+	APIKey   string
+	APIType  int
+	Config   model.ChannelConfig
+	IsStream bool
 	// OriginModelName is the model name from the raw user request
 	OriginModelName string
 	// ActualModelName is the model name after mapping

relay/relaymode/define.go

@@ -11,4 +11,6 @@ const (
 	AudioSpeech
 	AudioTranscription
 	AudioTranslation
+	// Proxy is a special relay mode for proxying requests to custom upstream
+	Proxy
 )

relay/relaymode/helper.go

@@ -24,6 +24,8 @@ func GetByPath(path string) int {
 		relayMode = AudioTranscription
 	} else if strings.HasPrefix(path, "/v1/audio/translations") {
 		relayMode = AudioTranslation
+	} else if strings.HasPrefix(path, "/v1/oneapi/proxy") {
+		relayMode = Proxy
 	}
 	return relayMode
 }