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
}
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)
}
// 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
}