func()

in pkg/controllers/openapi/aggregator/downloader.go [53:102]

• 40 lines of code
• 13 McCabe index (conditional complexity)

func (s *Downloader) Download(handler http.Handler, etag string) (returnSpec *spec.Swagger, newEtag string, httpStatus int, err error) {
	handler = s.handlerWithUser(handler, &user.DefaultInfo{Name: aggregatorUser})
	handler = http.TimeoutHandler(handler, specDownloadTimeout, "request timed out")

	req, err := http.NewRequest("GET", "/openapi/v2", nil)
	if err != nil {
		return nil, "", 0, err
	}
	req.Header.Add("Accept", "application/json")

	// Only pass eTag if it is not generated locally
	if len(etag) > 0 && !strings.HasPrefix(etag, locallyGeneratedEtagPrefix) {
		req.Header.Add("If-None-Match", etag)
	}

	writer := newInMemoryResponseWriter()
	handler.ServeHTTP(writer, req)

	switch writer.respCode {
	case http.StatusNotModified:
		if len(etag) == 0 {
			return nil, etag, http.StatusNotModified, fmt.Errorf("http.StatusNotModified is not allowed in absence of etag")
		}
		return nil, etag, http.StatusNotModified, nil
	case http.StatusNotFound:
		// Gracefully skip 404, assuming the server won't provide any spec
		return nil, "", http.StatusNotFound, nil
	case http.StatusOK:
		openAPISpec := &spec.Swagger{}
		if err := utiljson.Unmarshal(writer.data, openAPISpec); err != nil {
			return nil, "", 0, err
		}
		newEtag = writer.Header().Get("Etag")
		if len(newEtag) == 0 {
			newEtag = etagFor(writer.data)
			if len(etag) > 0 && strings.HasPrefix(etag, locallyGeneratedEtagPrefix) {
				// The function call with an etag and server does not report an etag.
				// That means this server does not support etag and the etag that passed
				// to the function generated previously by us. Just compare etags and
				// return StatusNotModified if they are the same.
				if etag == newEtag {
					return nil, etag, http.StatusNotModified, nil
				}
			}
		}
		return openAPISpec, newEtag, http.StatusOK, nil
	default:
		return nil, "", 0, fmt.Errorf("failed to retrieve openAPI spec, http error: %s", writer.String())
	}
}