package try import ( "fmt" "math" "net/http" "os" "time" "github.com/containous/traefik/log" ) const ( // CITimeoutMultiplier is the multiplier for all timeout in the CI CITimeoutMultiplier = 3 maxInterval = 5 * time.Second ) type timedAction func(timeout time.Duration, operation DoCondition) error // Sleep pauses the current goroutine for at least the duration d. // Deprecated: Use only when use an other Try[...] functions is not possible. func Sleep(d time.Duration) { d = applyCIMultiplier(d) time.Sleep(d) } // Response is like Request, but returns the response for further // processing at the call site. // Conditions are not allowed since it would complicate signaling if the // response body needs to be closed or not. Callers are expected to close on // their own if the function returns a nil error. func Response(req *http.Request, timeout time.Duration) (*http.Response, error) { return doTryRequest(req, timeout) } // ResponseUntilStatusCode is like Request, but returns the response for further // processing at the call site. // Conditions are not allowed since it would complicate signaling if the // response body needs to be closed or not. Callers are expected to close on // their own if the function returns a nil error. func ResponseUntilStatusCode(req *http.Request, timeout time.Duration, statusCode int) (*http.Response, error) { return doTryRequest(req, timeout, StatusCodeIs(statusCode)) } // GetRequest is like Do, but runs a request against the given URL and applies // the condition on the response. // ResponseCondition may be nil, in which case only the request against the URL must // succeed. func GetRequest(url string, timeout time.Duration, conditions ...ResponseCondition) error { resp, err := doTryGet(url, timeout, conditions...) if resp != nil && resp.Body != nil { defer resp.Body.Close() } return err } // Request is like Do, but runs a request against the given URL and applies // the condition on the response. // ResponseCondition may be nil, in which case only the request against the URL must // succeed. func Request(req *http.Request, timeout time.Duration, conditions ...ResponseCondition) error { resp, err := doTryRequest(req, timeout, conditions...) if resp != nil && resp.Body != nil { defer resp.Body.Close() } return err } // Do repeatedly executes an operation until no error condition occurs or the // given timeout is reached, whatever comes first. func Do(timeout time.Duration, operation DoCondition) error { if timeout <= 0 { panic("timeout must be larger than zero") } interval := time.Duration(math.Ceil(float64(timeout) / 15.0)) if interval > maxInterval { interval = maxInterval } timeout = applyCIMultiplier(timeout) var err error if err = operation(); err == nil { fmt.Println("+") return nil } fmt.Print("*") stopTimer := time.NewTimer(timeout) defer stopTimer.Stop() retryTick := time.NewTicker(interval) defer retryTick.Stop() for { select { case <-stopTimer.C: fmt.Println("-") return fmt.Errorf("try operation failed: %s", err) case <-retryTick.C: fmt.Print("*") if err = operation(); err == nil { fmt.Println("+") return err } } } } func doTryGet(url string, timeout time.Duration, conditions ...ResponseCondition) (*http.Response, error) { req, err := http.NewRequest(http.MethodGet, url, nil) if err != nil { return nil, err } return doTryRequest(req, timeout, conditions...) } func doTryRequest(request *http.Request, timeout time.Duration, conditions ...ResponseCondition) (*http.Response, error) { return doRequest(Do, timeout, request, conditions...) } func doRequest(action timedAction, timeout time.Duration, request *http.Request, conditions ...ResponseCondition) (*http.Response, error) { var resp *http.Response return resp, action(timeout, func() error { var err error client := http.DefaultClient resp, err = client.Do(request) if err != nil { return err } for _, condition := range conditions { if err := condition(resp); err != nil { return err } } return nil }) } func applyCIMultiplier(timeout time.Duration) time.Duration { ci := os.Getenv("CI") if len(ci) > 0 { log.Debug("Apply CI multiplier:", CITimeoutMultiplier) return time.Duration(float64(timeout) * CITimeoutMultiplier) } return timeout }