refactor: pipe the read and write process

this refactor simplify the process logic and fix several bugs and
performance issue.

bug fixed:
- cors headers not being sent in some situation
performance:
- perform upstream reqeust while clien is uploading content
This commit is contained in:
2024-05-27 14:47:00 +08:00
parent 45bba95f5d
commit 495f32610b
2 changed files with 157 additions and 248 deletions

View File

@@ -8,22 +8,14 @@ import (
"io"
"log"
"net/http"
"net/http/httputil"
"net/url"
"strings"
"time"
"github.com/gin-gonic/gin"
"golang.org/x/net/context"
)
func processRequest(c *gin.Context, upstream *OPENAI_UPSTREAM, record *Record, shouldResponse bool) error {
var errCtx []error
record.UpstreamEndpoint = upstream.Endpoint
record.UpstreamSK = upstream.SK
record.Response = ""
// [TODO] record request body
// reverse proxy
remote, err := url.Parse(upstream.Endpoint)
@@ -32,231 +24,102 @@ func processRequest(c *gin.Context, upstream *OPENAI_UPSTREAM, record *Record, s
}
path := strings.TrimPrefix(c.Request.URL.Path, "/v1")
// recoognize whisper url
remote.Path = upstream.URL.Path + path
log.Println("[proxy.begin]:", remote)
log.Println("[proxy.begin]: shouldResposne:", shouldResponse)
haveResponse := false
client := &http.Client{}
request := &http.Request{}
request.ContentLength = c.Request.ContentLength
request.Method = c.Request.Method
request.URL = remote
proxy := httputil.NewSingleHostReverseProxy(remote)
proxy.Director = nil
var inBody []byte
proxy.Rewrite = func(proxyRequest *httputil.ProxyRequest) {
in := proxyRequest.In
ctx, cancel := context.WithCancel(context.Background())
proxyRequest.Out = proxyRequest.Out.WithContext(ctx)
out := proxyRequest.Out
// read request body
inBody, err = io.ReadAll(in.Body)
if err != nil {
errCtx = append(errCtx, errors.New("[proxy.rewrite]: reverse proxy middleware failed to read request body "+err.Error()))
return
}
// record chat message from user
requestBody, requestBodyOK := ParseRequestBody(inBody)
// record if parse success
if requestBodyOK == nil && requestBody.Model != "" {
record.Model = requestBody.Model
record.Body = string(inBody)
}
// check allow list
if len(upstream.Allow) > 0 {
isAllow := false
for _, allow := range upstream.Allow {
if allow == record.Model {
isAllow = true
break
}
}
if !isAllow {
errCtx = append(errCtx, errors.New("[proxy.rewrite]: model '"+record.Model+"' not allowed"))
return
}
}
// check block list
if len(upstream.Deny) > 0 {
for _, deny := range upstream.Deny {
if deny == record.Model {
errCtx = append(errCtx, errors.New("[proxy.rewrite]: model '"+record.Model+"' denied"))
return
}
}
}
// set timeout, default is 60 second
timeout := time.Duration(upstream.Timeout) * time.Second
if requestBodyOK == nil && requestBody.Stream {
timeout = time.Duration(upstream.StreamTimeout) * time.Second
}
// timeout out request
go func() {
time.Sleep(timeout)
if !haveResponse {
log.Println("[proxy.timeout]: Timeout upstream", upstream.Endpoint, timeout)
errTimeout := errors.New("[proxy.timeout]: Timeout upstream")
errCtx = append(errCtx, errTimeout)
if shouldResponse {
c.Header("Content-Type", "application/json")
sendCORSHeaders(c)
c.AbortWithError(502, errTimeout)
}
cancel()
}
}()
out.Body = io.NopCloser(bytes.NewReader(inBody))
out.Host = remote.Host
out.URL.Scheme = remote.Scheme
out.URL.Host = remote.Host
if !upstream.KeepHeader {
out.Header = http.Header{}
}
out.Header.Set("Host", remote.Host)
if upstream.SK == "asis" {
out.Header.Set("Authorization", c.Request.Header.Get("Authorization"))
} else {
out.Header.Set("Authorization", "Bearer "+upstream.SK)
}
out.Header.Set("Content-Type", c.Request.Header.Get("Content-Type"))
}
var buf bytes.Buffer
var contentType string
proxy.ModifyResponse = func(r *http.Response) error {
haveResponse = true
record.ResponseTime = time.Since(record.CreatedAt)
record.Status = r.StatusCode
// remove response's cors headers
r.Header.Del("Access-Control-Allow-Origin")
r.Header.Del("Access-Control-Allow-Methods")
r.Header.Del("Access-Control-Allow-Headers")
r.Header.Del("access-control-allow-origin")
r.Header.Del("access-control-allow-methods")
r.Header.Del("access-control-allow-headers")
if !shouldResponse && r.StatusCode != 200 {
log.Println("[proxy.modifyResponse]: upstream return not 200 and should not response", r.StatusCode)
return errors.New("upstream return not 200 and should not response")
}
if r.StatusCode != 200 {
body, err := io.ReadAll(r.Body)
if err != nil {
errRet := errors.New("[proxy.modifyResponse]: failed to read response from upstream " + err.Error())
return errRet
}
errRet := fmt.Errorf("[error]: openai-api-route upstream return '%s' with '%s'", r.Status, string(body))
log.Println(errRet)
record.Status = r.StatusCode
return errRet
}
// handle reverse proxy cors header if upstream do not set that
sendCORSHeaders(c)
// count success
r.Body = io.NopCloser(io.TeeReader(r.Body, &buf))
contentType = r.Header.Get("content-type")
return nil
}
proxy.ErrorHandler = func(w http.ResponseWriter, r *http.Request, err error) {
haveResponse = true
record.ResponseTime = time.Since(record.CreatedAt)
log.Println("[proxy.errorHandler]", err, upstream.SK, upstream.Endpoint, errCtx)
errCtx = append(errCtx, err)
// abort to error handle
if shouldResponse {
c.Header("Content-Type", "application/json")
sendCORSHeaders(c)
for _, err := range errCtx {
c.AbortWithError(502, err)
}
}
log.Println("[proxy.errorHandler]: response is", r.Response)
if record.Status == 0 {
record.Status = 502
}
record.Response += "[proxy.ErrorHandler]: " + err.Error()
if r.Response != nil {
record.Status = r.Response.StatusCode
}
}
err = ServeHTTP(proxy, c.Writer, c.Request)
if err != nil {
log.Println("[proxy.serve]: error from ServeHTTP:", err)
// panic means client has abort the http connection
// since the connection is lost, we return
// and the reverse process should not try the next upsteam
return http.ErrAbortHandler
}
// return context error
if len(errCtx) > 0 {
log.Println("[proxy.serve]: error from ServeHTTP:", errCtx)
// fix inrequest body
c.Request.Body = io.NopCloser(bytes.NewReader(inBody))
return errCtx[len(errCtx)-1]
}
resp, err := io.ReadAll(io.NopCloser(&buf))
if err != nil {
record.Response = "failed to read response from upstream " + err.Error()
log.Println(record.Response)
// process header
if upstream.KeepHeader {
request.Header = c.Request.Header
} else {
request.Header = http.Header{}
}
// record response
// stream mode
if strings.HasPrefix(contentType, "text/event-stream") {
for _, line := range strings.Split(string(resp), "\n") {
chunk := StreamModeChunk{}
line = strings.TrimPrefix(line, "data:")
line = strings.TrimSpace(line)
if line == "" {
continue
}
// process header authorization
if upstream.SK == "asis" {
request.Header.Set("Authorization", c.Request.Header.Get("Authorization"))
} else {
request.Header.Set("Authorization", "Bearer "+upstream.SK)
}
request.Header.Set("Content-Type", c.Request.Header.Get("Content-Type"))
request.Header.Set("Host", remote.Host)
request.Header.Set("Content-Length", c.Request.Header.Get("Content-Length"))
err := json.Unmarshal([]byte(line), &chunk)
if err != nil {
log.Println("[proxy.parseChunkError]:", err)
continue
}
request.Body = c.Request.Body
if len(chunk.Choices) == 0 {
continue
}
record.Response += chunk.Choices[0].Delta.Content
}
} else if strings.HasPrefix(contentType, "text") {
record.Response = string(resp)
} else if strings.HasPrefix(contentType, "application/json") {
// fallback record response
if len(resp) < 1024*128 {
record.Response = string(resp)
}
var fetchResp FetchModeResponse
err := json.Unmarshal(resp, &fetchResp)
if err == nil {
if len(fetchResp.Choices) > 0 {
record.Response = fetchResp.Choices[0].Message.Content
}
}
} else {
log.Println("[proxy.record]: Unknown content type", contentType)
resp, err := client.Do(request)
if err != nil {
body := []byte{}
if resp != nil && resp.Body != nil {
body, _ = io.ReadAll(resp.Body)
}
return errors.New(err.Error() + " " + string(body))
}
defer resp.Body.Close()
record.Status = resp.StatusCode
if resp.StatusCode != 200 {
body, _ := io.ReadAll(resp.Body)
record.Status = resp.StatusCode
errRet := fmt.Errorf("[error]: openai-api-route upstream return '%s' with '%s'", resp.Status, string(body))
log.Println(errRet)
return errRet
}
// copy response header
for k, v := range resp.Header {
c.Header(k, v[0])
}
sendCORSHeaders(c)
respBodyBuffer := bytes.NewBuffer(make([]byte, 0, 4*1024))
respBodyTeeReader := io.TeeReader(resp.Body, respBodyBuffer)
record.ResponseTime = time.Since(record.CreatedAt)
io.Copy(c.Writer, respBodyTeeReader)
record.ElapsedTime = time.Since(record.CreatedAt)
// parse and record response
if strings.HasPrefix(resp.Header.Get("Content-Type"), "application/json") {
var fetchResp FetchModeResponse
err := json.NewDecoder(respBodyBuffer).Decode(&fetchResp)
if err == nil {
if len(fetchResp.Choices) > 0 {
record.Response = fetchResp.Choices[0].Message.Content
}
}
} else if strings.HasPrefix(resp.Header.Get("Content-Type"), "text/event-stream") {
lines := bytes.Split(respBodyBuffer.Bytes(), []byte("\n"))
for _, line := range lines {
line = bytes.TrimSpace(line)
line = bytes.TrimPrefix(line, []byte("data:"))
line = bytes.TrimSpace(line)
if len(line) == 0 {
continue
}
chunk := StreamModeChunk{}
err = json.Unmarshal(line, &chunk)
if err != nil {
log.Println("[proxy.parseChunkError]:", err)
break
}
if len(chunk.Choices) == 0 {
continue
}
record.Response += chunk.Choices[0].Delta.Content
}
} else if strings.HasPrefix(resp.Header.Get("Content-Type"), "text") {
body, _ := io.ReadAll(respBodyBuffer)
record.Response = string(body)
} else {
log.Println("[proxy.record]: Unknown content type", resp.Header.Get("Content-Type"))
}
return nil