Golang http.RoundTripper類代碼示例

func (p *Prometheus) gatherURL(url string, acc telegraf.Accumulator) error {
	collectDate := time.Now()
	var req, err = http.NewRequest("GET", url, nil)
	req.Header.Add("Accept", acceptHeader)
	var token []byte
	var resp *http.Response

	tlsCfg, err := internal.GetTLSConfig(
		p.SSLCert, p.SSLKey, p.SSLCA, p.InsecureSkipVerify)
	if err != nil {
		return err
	}

	var rt http.RoundTripper = &http.Transport{
		Dial: (&net.Dialer{
			Timeout:   5 * time.Second,
			KeepAlive: 30 * time.Second,
		}).Dial,
		TLSHandshakeTimeout:   5 * time.Second,
		TLSClientConfig:       tlsCfg,
		ResponseHeaderTimeout: time.Duration(3 * time.Second),
		DisableKeepAlives:     true,
	}

	if p.BearerToken != "" {
		token, err = ioutil.ReadFile(p.BearerToken)
		if err != nil {
			return err
		}
		req.Header.Set("Authorization", "Bearer "+string(token))
	}

	resp, err = rt.RoundTrip(req)
	if err != nil {
		return fmt.Errorf("error making HTTP request to %s: %s", url, err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("%s returned HTTP status %s", url, resp.Status)
	}

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return fmt.Errorf("error reading body: %s", err)
	}

	metrics, err := Parse(body, resp.Header)
	if err != nil {
		return fmt.Errorf("error reading metrics for %s: %s",
			url, err)
	}
	// Add (or not) collected metrics
	for _, metric := range metrics {
		tags := metric.Tags()
		tags["url"] = url
		acc.AddFields(metric.Name(), metric.Fields(), tags, collectDate)
	}

	return nil
}

// RoundTrip implements the RoundTripper interface.
func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
	var transport http.RoundTripper
	if t.Transport != nil {
		transport = t.Transport
	} else {
		transport = http.DefaultTransport
	}

	// To set extra querystring params, we must make a copy of the Request so
	// that we don't modify the Request we were given. This is required by the
	// specification of http.RoundTripper.
	req = cloneRequest(req)

	child := t.Recorder.Child()
	if t.SetName {
		child.Name(req.URL.Host)
	}
	SetSpanIDHeader(req.Header, child.SpanID)

	e := NewClientEvent(req)
	e.ClientSend = time.Now()

	// Make the HTTP request.
	resp, err := transport.RoundTrip(req)

	e.ClientRecv = time.Now()
	if err == nil {
		e.Response = responseInfo(resp)
	} else {
		e.Response.StatusCode = -1
	}
	child.Event(e)

	return resp, err
}

// Dial dials to the remote url, and sends streaming request. If it succeeds,
// it returns nil error, and the caller should call Handle function to keep
// receiving appendEntry messages.
func (s *streamClient) start(tr http.RoundTripper, u string, cid types.ID) error {
	uu, err := url.Parse(u)
	if err != nil {
		return fmt.Errorf("parse url %s error: %v", u, err)
	}
	uu.Path = path.Join(RaftStreamPrefix, s.id.String())
	req, err := http.NewRequest("GET", uu.String(), nil)
	if err != nil {
		return fmt.Errorf("new request to %s error: %v", u, err)
	}
	req.Header.Set("X-Etcd-Cluster-ID", cid.String())
	req.Header.Set("X-Raft-To", s.to.String())
	req.Header.Set("X-Raft-Term", strconv.FormatUint(s.term, 10))
	resp, err := tr.RoundTrip(req)
	if err != nil {
		return fmt.Errorf("error posting to %q: %v", u, err)
	}
	if resp.StatusCode != http.StatusOK {
		resp.Body.Close()
		return fmt.Errorf("unhandled http status %d", resp.StatusCode)
	}
	s.closer = resp.Body
	go s.handle(resp.Body)
	log.Printf("rafthttp: starting client stream to %s at term %d", s.to, s.term)
	return nil
}

func (t *tracingTransport) RoundTrip(req *http.Request) (*http.Response, error) {
	var u http.RoundTripper
	if t.Transport != nil {
		u = t.Transport
	} else {
		u = http.DefaultTransport
	}

	reqBytes, err := httputil.DumpRequestOut(req, true)
	if err != nil {
		return nil, err
	}
	t.Writer.Write(reqBytes)

	resp, err := u.RoundTrip(req)
	if err != nil {
		return nil, err
	}

	respBytes, err := httputil.DumpResponse(resp, true)
	if err != nil {
		return nil, err
	}
	t.Writer.Write(respBytes)

	return resp, nil
}

func main() {
	//Set URL to test --- test will NOT follow redirects
	testurl := "https://beacon.walmart.com/vm/ttap.gif?id=10694084&160x600&audience=&creative=1027467&creativetype=rich_media&device=&initiative=209902&placement=SSLTEST&targeting=wmxaudience&vendor=AOD&version=2015802"

	// Set log filename
	logfile := "testlog.txt"

	var DefaultTransport http.RoundTripper = &http.Transport{}

	// Set number of requests
	for i := 0; i < 500000; i++ {

		req, _ := http.NewRequest("GET", testurl, nil)

		resp, _ := DefaultTransport.RoundTrip(req)

		logger, err := os.OpenFile(logfile, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
		if err != nil {
			log.Fatal(err)
		}

		defer logger.Close()

		// Grab specified headers from HTTP response
		location := resp.Header.Get("Location")
		cookie := resp.Header.Get("Set-Cookie")
		t := time.Now().UTC().String()
		result := fmt.Sprintf("%s\t%s\t%s\r\n", t, location, cookie)
		logger.WriteString(result)

		// Wait time before next request
		time.Sleep(time.Second)
	}
}

// newStreamClient starts and returns a new started stream client.
// The caller should call stop when finished, to shut it down.
func newStreamReader(id, to, cid types.ID, term uint64, tr http.RoundTripper, u string, r Raft) (*streamReader, error) {
	s := &streamReader{
		id:   id,
		to:   to,
		term: term,
		r:    r,
		done: make(chan struct{}),
	}

	uu, err := url.Parse(u)
	if err != nil {
		return nil, fmt.Errorf("parse url %s error: %v", u, err)
	}
	uu.Path = path.Join(RaftStreamPrefix, s.id.String())
	req, err := http.NewRequest("GET", uu.String(), nil)
	if err != nil {
		return nil, fmt.Errorf("new request to %s error: %v", u, err)
	}
	req.Header.Set("X-Etcd-Cluster-ID", cid.String())
	req.Header.Set("X-Raft-To", s.to.String())
	req.Header.Set("X-Raft-Term", strconv.FormatUint(s.term, 10))
	resp, err := tr.RoundTrip(req)
	if err != nil {
		return nil, fmt.Errorf("error posting to %q: %v", u, err)
	}
	if resp.StatusCode != http.StatusOK {
		resp.Body.Close()
		return nil, fmt.Errorf("unhandled http status %d", resp.StatusCode)
	}
	s.closer = resp.Body
	go s.handle(resp.Body)
	log.Printf("rafthttp: starting client stream to %s at term %d", s.to, s.term)
	return s, nil
}

func roundTrip(rt http.RoundTripper, req *http.Request) (body []byte, err error) {
	resp, err := rt.RoundTrip(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	body, err = ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}
	return body, nil
}

// ReqThrottledRoundTripper wraps another RoundTripper rt,
// throttling all requests to the specified request rate.
func ReqThrottledRoundTripper(rt http.RoundTripper, rate int64) http.RoundTripper {
	freq := time.Duration(1e9 / rate)
	bucket := tb.NewBucket(rate, freq)

	return roundTripperFunc(func(r *http.Request) (*http.Response, error) {
		got := bucket.Take(1)
		for got != 1 {
			got = bucket.Take(1)
			time.Sleep(freq)
		}
		return rt.RoundTrip(r)
	})
}

// ByteThrottledRoundTripper wraps another RoundTripper rt,
// throttling all requests to the specified byte rate.
func ByteThrottledRoundTripper(rt http.RoundTripper, rate int64) http.RoundTripper {
	freq := time.Duration(1 * time.Millisecond)
	bucket := tb.NewBucket(rate, freq)

	return roundTripperFunc(func(r *http.Request) (*http.Response, error) {
		got := bucket.Take(r.ContentLength)
		for got < r.ContentLength {
			got += bucket.Take(r.ContentLength - got)
			time.Sleep(freq)
		}
		return rt.RoundTrip(r)
	})
}

func request(rt http.RoundTripper, requestURL string, requestHeaders http.Header) (*http.Response, error) {
	// Build the request
	req, err := http.NewRequest("GET", requestURL, nil)
	if err != nil {
		return nil, err
	}
	for k, v := range requestHeaders {
		req.Header[k] = v
	}
	req.Header.Set(CSRFTokenHeader, "1")

	// Make the request
	return rt.RoundTrip(req)
}

// HTTPGet creates a new http request
func HTTPGet(url string, follow, insecure bool, h map[string]string, timeout ...int) (*http.Response, error) {
	// timeout in seconds defaults to 5
	var t int = 5

	if len(timeout) > 0 {
		t = timeout[0]
	}

	// if insecure = true, skip ssl verification
	tr := &http.Transport{
		Dial: (&net.Dialer{
			Timeout:   30 * time.Second,
			KeepAlive: 30 * time.Second,
		}).Dial,
		TLSHandshakeTimeout:   10 * time.Second,
		TLSClientConfig:       &tls.Config{InsecureSkipVerify: insecure},
		ResponseHeaderTimeout: time.Duration(t) * time.Second,
	}

	client := &http.Client{}
	client.Transport = tr

	// create a new request
	req, _ := http.NewRequest("GET", url, nil)
	req.Header.Set("User-Agent", "epazote")

	// set custom headers on request
	if h != nil {
		for k, v := range h {
			req.Header.Set(k, v)
		}
	}

	if follow {
		res, err := client.Do(req)
		if err != nil {
			return nil, err
		}
		return res, nil
	}

	// not follow redirects
	var DefaultTransport http.RoundTripper = tr

	res, err := DefaultTransport.RoundTrip(req)
	if err != nil {
		return nil, err
	}
	return res, nil
}

func TLSClientConfig(transport http.RoundTripper) (*tls.Config, error) {
	if transport == nil {
		return nil, nil
	}

	switch transport := transport.(type) {
	case *http.Transport:
		return transport.TLSClientConfig, nil
	case RoundTripperWrapper:
		return TLSClientConfig(transport.WrappedRoundTripper())
	default:
		return nil, fmt.Errorf("unknown transport type: %v", transport)
	}
}

func Dialer(transport http.RoundTripper) (DialFunc, error) {
	if transport == nil {
		return nil, nil
	}

	switch transport := transport.(type) {
	case *http.Transport:
		return transport.Dial, nil
	case RoundTripperWrapper:
		return Dialer(transport.WrappedRoundTripper())
	default:
		return nil, fmt.Errorf("unknown transport type: %v", transport)
	}
}

func (S) TestTransport(c *gocheck.C) {
	var t http.RoundTripper = &Transport{
		Message: "Ok",
		Status:  http.StatusOK,
		Headers: map[string][]string{"Authorization": {"something"}},
	}
	req, _ := http.NewRequest("GET", "/", nil)
	r, err := t.RoundTrip(req)
	c.Assert(err, gocheck.IsNil)
	c.Assert(r.StatusCode, gocheck.Equals, http.StatusOK)
	defer r.Body.Close()
	b, _ := ioutil.ReadAll(r.Body)
	c.Assert(string(b), gocheck.Equals, "Ok")
	c.Assert(r.Header.Get("Authorization"), gocheck.Equals, "something")
}

// NewRoundTripper creates an http.RoundTripper to instrument external requests.
// This RoundTripper must be used in same the goroutine as the other uses of the
// Transaction's SegmentTracer methods.  http.DefaultTransport is used if an
// http.RoundTripper is not provided.
//
//   client := &http.Client{}
//   client.Transport = newrelic.NewRoundTripper(txn, nil)
//   resp, err := client.Get("http://example.com/")
//
func NewRoundTripper(txn Transaction, original http.RoundTripper) http.RoundTripper {
	return roundTripperFunc(func(request *http.Request) (*http.Response, error) {
		segment := StartExternalSegment(txn, request)

		if nil == original {
			original = http.DefaultTransport
		}
		response, err := original.RoundTrip(request)

		segment.Response = response
		segment.End()

		return response, err
	})
}