Golang unversioned.Do函數代碼示例

func scrapeMetrics(s *httptest.Server) ([]*prometheuspb.MetricFamily, error) {
	req, err := http.NewRequest("GET", s.URL+"/metrics", nil)
	if err != nil {
		return nil, fmt.Errorf("Unable to create http request: %v", err)
	}
	// Ask the prometheus exporter for its text protocol buffer format, since it's
	// much easier to parse than its plain-text format. Don't use the serialized
	// proto representation since it uses a non-standard varint delimiter between
	// metric families.
	req.Header.Add("Accept", scrapeRequestHeader)

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("Unable to contact metrics endpoint of master: %v", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		return nil, fmt.Errorf("Non-200 response trying to scrape metrics from master: %v", resp)
	}

	// Each line in the response body should contain all the data for a single metric.
	var metrics []*prometheuspb.MetricFamily
	scanner := bufio.NewScanner(resp.Body)
	for scanner.Scan() {
		var metric prometheuspb.MetricFamily
		if err := proto.UnmarshalText(scanner.Text(), &metric); err != nil {
			return nil, fmt.Errorf("Failed to unmarshal line of metrics response: %v", err)
		}
		glog.Infof("Got metric %q", metric.GetName())
		metrics = append(metrics, &metric)
	}
	return metrics, nil
}

// Dial opens a connection to a remote server and attempts to negotiate a SPDY
// connection. Upon success, it returns the connection and the protocol
// selected by the server.
func (e *streamExecutor) Dial(protocols ...string) (httpstream.Connection, string, error) {
	rt := transport.DebugWrappers(e.transport)

	// TODO the client probably shouldn't be created here, as it doesn't allow
	// flexibility to allow callers to configure it.
	client := &http.Client{Transport: rt}

	req, err := http.NewRequest(e.method, e.url.String(), nil)
	if err != nil {
		return nil, "", fmt.Errorf("error creating request: %v", err)
	}
	for i := range protocols {
		req.Header.Add(httpstream.HeaderProtocolVersion, protocols[i])
	}

	resp, err := client.Do(req)
	if err != nil {
		return nil, "", fmt.Errorf("error sending request: %v", err)
	}
	defer resp.Body.Close()

	conn, err := e.upgrader.NewConnection(resp)
	if err != nil {
		return nil, "", err
	}

	return conn, resp.Header.Get(httpstream.HeaderProtocolVersion), nil
}

func httpDelete(url string) (*http.Response, error) {
	req, err := http.NewRequest("DELETE", url, nil)
	if err != nil {
		return nil, err
	}
	client := &http.Client{}
	return client.Do(req)
}

func doPut(url, content string) (string, error) {
	req, err := http.NewRequest("PUT", url, bytes.NewBuffer([]byte(content)))
	req.Header.Set("Content-Type", "application/json")
	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}
	strBody := string(body)
	return strBody, nil
}

// Dial opens a connection to a remote server and attempts to negotiate a SPDY
// connection. Upon success, it returns the connection and the protocol
// selected by the server.
func (e *streamExecutor) Dial(protocols ...string) (httpstream.Connection, string, error) {
	transport := e.transport
	// TODO consider removing this and reusing client.TransportFor above to get this for free
	switch {
	case bool(glog.V(9)):
		transport = client.NewDebuggingRoundTripper(transport, client.CurlCommand, client.URLTiming, client.ResponseHeaders)
	case bool(glog.V(8)):
		transport = client.NewDebuggingRoundTripper(transport, client.JustURL, client.RequestHeaders, client.ResponseStatus, client.ResponseHeaders)
	case bool(glog.V(7)):
		transport = client.NewDebuggingRoundTripper(transport, client.JustURL, client.RequestHeaders, client.ResponseStatus)
	case bool(glog.V(6)):
		transport = client.NewDebuggingRoundTripper(transport, client.URLTiming)
	}

	// TODO the client probably shouldn't be created here, as it doesn't allow
	// flexibility to allow callers to configure it.
	client := &http.Client{Transport: transport}

	req, err := http.NewRequest(e.method, e.url.String(), nil)
	if err != nil {
		return nil, "", fmt.Errorf("error creating request: %v", err)
	}
	for i := range protocols {
		req.Header.Add(httpstream.HeaderProtocolVersion, protocols[i])
	}

	resp, err := client.Do(req)
	if err != nil {
		return nil, "", fmt.Errorf("error sending request: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusSwitchingProtocols {
		return nil, "", fmt.Errorf("unexpected response status code %d (%s)", resp.StatusCode, http.StatusText(resp.StatusCode))
	}

	conn, err := e.upgrader.NewConnection(resp)
	if err != nil {
		return nil, "", err
	}

	return conn, resp.Header.Get(httpstream.HeaderProtocolVersion), nil
}