Function RequestIDHandler

maintenance/log/handler.go:108–151

(fieldKey, headerName string)

}

func RequestIDHandler(fieldKey, headerName string) func(next http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			ctx := r.Context()
			var id xid.ID

			// try extract of xid from header
			reqID := r.Header.Get(headerName)
			if reqID != "" {
				id, _ = xid.FromString(reqID)
			}

			// try extract of xid context
			if id.Compare(xid.NilID()) == 0 {
				if nid, ok := hlog.IDFromCtx(ctx); ok {
					id = nid
				}
			}

			// give up, generate a new xid
			if id.Compare(xid.NilID()) == 0 {
				id = xid.New()
			}

			ctx = hlog.WithValue(ctx, id)
			r = r.WithContext(ctx)

			transaction := sentry.TransactionFromContext(ctx)
			if transaction != nil {
				transaction.SetData("http.request.id", id.String())
			}

			// log requests with request id
			log := zerolog.Ctx(ctx)
			log.UpdateContext(func(c zerolog.Context) zerolog.Context {
				return c.Str(fieldKey, id.String())
			})

			// return the request id as a header to the client
			w.Header().Set(headerName, id.String())
			next.ServeHTTP(w, r)
		})
	}
}