feat: passthrough upstream response headers to clients

CPA previously stripped ALL response headers from upstream AI provider
APIs, preventing clients from seeing rate-limit info, request IDs,
server-timing and other useful headers.

Changes:
- Add Headers field to Response and StreamResult structs
- Add FilterUpstreamHeaders helper (hop-by-hop + security denylist)
- Add WriteUpstreamHeaders helper (respects CPA-set headers)
- ExecuteWithAuthManager/ExecuteCountWithAuthManager now return headers
- ExecuteStreamWithAuthManager returns headers from initial connection
- All 11 provider executors populate Response.Headers
- All handler call sites write filtered upstream headers before response

Filtered headers (not forwarded):
- RFC 7230 hop-by-hop: Connection, Transfer-Encoding, Keep-Alive, etc.
- Security: Set-Cookie
- CPA-managed: Content-Length, Content-Encoding
This commit is contained in:
Kirill Turanskiy
2026-02-18 00:16:22 +03:00
parent 453aaf8774
commit 1f8f198c45
24 changed files with 192 additions and 107 deletions

View File

@@ -159,7 +159,8 @@ func (h *GeminiCLIAPIHandler) handleInternalStreamGenerateContent(c *gin.Context
modelName := modelResult.String()
cliCtx, cliCancel := h.GetContextWithCancel(h, c, context.Background())
dataChan, errChan := h.ExecuteStreamWithAuthManager(cliCtx, h.HandlerType(), modelName, rawJSON, "")
dataChan, upstreamHeaders, errChan := h.ExecuteStreamWithAuthManager(cliCtx, h.HandlerType(), modelName, rawJSON, "")
handlers.WriteUpstreamHeaders(c.Writer.Header(), upstreamHeaders)
h.forwardCLIStream(c, flusher, "", func(err error) { cliCancel(err) }, dataChan, errChan)
return
}
@@ -172,12 +173,13 @@ func (h *GeminiCLIAPIHandler) handleInternalGenerateContent(c *gin.Context, rawJ
modelName := modelResult.String()
cliCtx, cliCancel := h.GetContextWithCancel(h, c, context.Background())
resp, errMsg := h.ExecuteWithAuthManager(cliCtx, h.HandlerType(), modelName, rawJSON, "")
resp, upstreamHeaders, errMsg := h.ExecuteWithAuthManager(cliCtx, h.HandlerType(), modelName, rawJSON, "")
if errMsg != nil {
h.WriteErrorResponse(c, errMsg)
cliCancel(errMsg.Error)
return
}
handlers.WriteUpstreamHeaders(c.Writer.Header(), upstreamHeaders)
_, _ = c.Writer.Write(resp)
cliCancel()
}