func()

in rest/request.go [928:1028]

• 77 lines of code
• 18 McCabe index (conditional complexity)

func (r *Request) request(ctx context.Context, fn func(*http.Request, *http.Response)) error {
	//Metrics for total request latency
	start := time.Now()
	defer func() {
		metrics.RequestLatency.Observe(ctx, r.verb, r.finalURLTemplate(), time.Since(start))
	}()

	if r.err != nil {
		klog.V(4).Infof("Error in request: %v", r.err)
		return r.err
	}

	if err := r.requestPreflightCheck(); err != nil {
		return err
	}

	client := r.c.Client
	if client == nil {
		client = http.DefaultClient
	}

	// Throttle the first try before setting up the timeout configured on the
	// client. We don't want a throttled client to return timeouts to callers
	// before it makes a single request.
	if err := r.tryThrottle(ctx); err != nil {
		return err
	}

	if r.timeout > 0 {
		var cancel context.CancelFunc
		ctx, cancel = context.WithTimeout(ctx, r.timeout)
		defer cancel()
	}

	// Right now we make about ten retry attempts if we get a Retry-After response.
	var retryAfter *RetryAfter
	for {
		req, err := r.newHTTPRequest(ctx)
		if err != nil {
			return err
		}

		r.backoff.Sleep(r.backoff.CalculateBackoff(r.URL()))
		if retryAfter != nil {
			// We are retrying the request that we already send to apiserver
			// at least once before.
			// This request should also be throttled with the client-internal rate limiter.
			if err := r.tryThrottleWithInfo(ctx, retryAfter.Reason); err != nil {
				return err
			}
			retryAfter = nil
		}
		resp, err := client.Do(req)
		updateURLMetrics(ctx, r, resp, err)
		if err != nil {
			r.backoff.UpdateBackoff(r.URL(), err, 0)
		} else {
			r.backoff.UpdateBackoff(r.URL(), err, resp.StatusCode)
		}

		done := func() bool {
			defer readAndCloseResponseBody(resp)

			// if the the server returns an error in err, the response will be nil.
			f := func(req *http.Request, resp *http.Response) {
				if resp == nil {
					return
				}
				fn(req, resp)
			}

			var retry bool
			retryAfter, retry = r.retry.NextRetry(req, resp, err, func(req *http.Request, err error) bool {
				// "Connection reset by peer" or "apiserver is shutting down" are usually a transient errors.
				// Thus in case of "GET" operations, we simply retry it.
				// We are not automatically retrying "write" operations, as they are not idempotent.
				if r.verb != "GET" {
					return false
				}
				// For connection errors and apiserver shutdown errors retry.
				if net.IsConnectionReset(err) || net.IsProbableEOF(err) {
					return true
				}
				return false
			})
			if retry {
				err := r.retry.BeforeNextRetry(ctx, r.backoff, retryAfter, req.URL.String(), r.body)
				if err == nil {
					return false
				}
				klog.V(4).Infof("Could not retry request - %v", err)
			}

			f(req, resp)
			return true
		}()
		if done {
			return err
		}
	}
}