125 lines
3.9 KiB
Go
125 lines
3.9 KiB
Go
package http
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import (
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"context"
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"encoding/json"
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"io"
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"net/http"
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"strings"
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"hyapp/pkg/idgen"
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"hyapp/pkg/xerr"
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"google.golang.org/grpc/status"
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)
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type requestIDContextKey struct{}
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const (
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codeOK = "OK"
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codeInvalidJSON = "INVALID_JSON"
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codeInvalidArgument = "INVALID_ARGUMENT"
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codeUnauthorized = "UNAUTHORIZED"
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codePermissionDenied = "PERMISSION_DENIED"
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codeProfileRequired = "PROFILE_REQUIRED"
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codeAuthLoginBlocked = "AUTH_LOGIN_BLOCKED"
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codeNotFound = "NOT_FOUND"
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codeRateLimited = "RATE_LIMITED"
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codeUpstreamError = "UPSTREAM_ERROR"
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codeInternalError = "INTERNAL_ERROR"
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)
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// responseEnvelope 是 gateway 暴露给客户端的稳定 JSON 外壳。
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// HTTP status 表示传输层结果，code 表示客户端可依赖的错误语义。
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type responseEnvelope struct {
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Code string `json:"code"`
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Message string `json:"message"`
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RequestID string `json:"request_id"`
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Data any `json:"data,omitempty"`
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}
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// withRequestID 为每个业务 API 请求建立追踪 ID。
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// 客户端传入 X-Request-ID 时沿用，未传时由 gateway 生成，后续 gRPC RequestMeta 复用同一个值。
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func withRequestID(next http.Handler) http.Handler {
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return http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
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requestID := strings.TrimSpace(request.Header.Get("X-Request-ID"))
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if requestID == "" {
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requestID = idgen.New("req")
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}
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writer.Header().Set("X-Request-ID", requestID)
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ctx := context.WithValue(request.Context(), requestIDContextKey{}, requestID)
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next.ServeHTTP(writer, request.WithContext(ctx))
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})
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}
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// requestIDFromContext 读取当前 HTTP 请求的追踪 ID。
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// 理论上业务路由都会先经过 withRequestID；兜底生成值只用于防御错误调用。
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func requestIDFromContext(ctx context.Context) string {
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requestID, _ := ctx.Value(requestIDContextKey{}).(string)
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if requestID != "" {
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return requestID
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}
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return idgen.New("req")
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}
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// decodeJSON 隔离 JSON 解码细节，避免 handler 直接依赖 envelope 写法。
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func decodeJSON(reader io.Reader, out any) error {
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return json.NewDecoder(reader).Decode(out)
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}
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// writeOK 写成功 envelope。
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func writeOK(writer http.ResponseWriter, request *http.Request, data any) {
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writeEnvelope(writer, http.StatusOK, responseEnvelope{
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Code: codeOK,
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Message: "ok",
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RequestID: responseRequestID(request),
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Data: data,
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})
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}
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// writeError 写失败 envelope。
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// 错误 message 保持稳定、短小，排障依赖 request_id 追日志，而不是把内部错误直接暴露给客户端。
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func writeError(writer http.ResponseWriter, request *http.Request, statusCode int, code string, message string) {
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writeEnvelope(writer, statusCode, responseEnvelope{
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Code: code,
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Message: message,
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RequestID: responseRequestID(request),
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})
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}
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// writeRPCError 把内部 gRPC status + ErrorInfo.reason 转成外部稳定 envelope。
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func writeRPCError(writer http.ResponseWriter, request *http.Request, err error) {
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if err == nil {
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return
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}
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if _, ok := status.FromError(err); !ok {
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writeError(writer, request, http.StatusBadGateway, codeUpstreamError, "upstream service error")
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return
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}
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reason := xerr.ReasonFromGRPC(err)
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statusCode, code, message := mapReasonToHTTP(reason)
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writeError(writer, request, statusCode, code, message)
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}
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func mapReasonToHTTP(reason xerr.Code) (int, string, string) {
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spec := xerr.SpecOf(reason)
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return spec.HTTPStatus, spec.PublicCode, spec.PublicMessage
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}
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// writeEnvelope 是 gateway 业务 API 的唯一 JSON 响应出口。
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func writeEnvelope(writer http.ResponseWriter, statusCode int, response responseEnvelope) {
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writer.Header().Set("Content-Type", "application/json")
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writer.WriteHeader(statusCode)
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if err := json.NewEncoder(writer).Encode(response); err != nil {
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return
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}
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}
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// responseRequestID 统一确定响应中的 request_id。
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func responseRequestID(request *http.Request) string {
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return requestIDFromContext(request.Context())
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}
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