set user agent on scrape requests to nginx.

client/nginx.go

@@ -12,7 +12,6 @@ import (
 type NginxClient struct {
  apiEndpoint string
  httpClient *http.Client
- appName string
 }
 
 // StubStats represents NGINX stub_status metrics.
@@ -32,11 +31,10 @@ type StubConnections struct {
 }
 
 // NewNginxClient creates an NginxClient.
-func NewNginxClient(httpClient *http.Client, apiEndpoint string, appName string) (*NginxClient, error) {
+func NewNginxClient(httpClient *http.Client, apiEndpoint string) (*NginxClient, error) {
  client := &NginxClient{
  apiEndpoint: apiEndpoint,
  httpClient: httpClient,
- appName: appName,
  }
 
  _, err := client.GetStubStats()
@@ -45,13 +43,7 @@ func NewNginxClient(httpClient *http.Client, apiEndpoint string, appName string)
 
 // GetStubStats fetches the stub_status metrics.
 func (client *NginxClient) GetStubStats() (*StubStats, error) {
-
- req, err := http.NewRequest("GET", client.apiEndpoint, nil)
- if err != nil {
- return nil, fmt.Errorf("failed to create get request %v: %v", client.apiEndpoint, err)
- }
- req.Header.Set("User-Agent", client.appName)
- resp, err := client.httpClient.Do(req)
+ resp, err := client.httpClient.Get(client.apiEndpoint)
  if err != nil {
  return nil, fmt.Errorf("failed to get %v: %v", client.apiEndpoint, err)
  }

exporter.go

@@ -177,11 +177,11 @@ func main() {
 
  registry.MustRegister(buildInfoMetric)
 
+ userAgent := fmt.Sprintf("NGINX-Prometheus-Exporter/v%v", version)
+ userAgentRT := &userAgentRoundTripper{agent: userAgent, rt: &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: !*sslVerify}}}
  httpClient := &http.Client{
- Timeout: timeout.Duration,
- Transport: &http.Transport{
- TLSClientConfig: &tls.Config{InsecureSkipVerify: !*sslVerify},
- },
+ Timeout: timeout.Duration,
+ Transport: userAgentRT,
  }
 
  signalChan := make(chan os.Signal, 1)
@@ -200,9 +200,8 @@ func main() {
  }
  registry.MustRegister(collector.NewNginxPlusCollector(plusClient.(*plusclient.NginxClient), "nginxplus"))
  } else {
- appName := fmt.Sprintf("NGINX-Prometheus-Exporter/v%v", version)
  ossClient, err := createClientWithRetries(func() (interface{}, error) {
- return client.NewNginxClient(httpClient, *scrapeURI, appName)
+ return client.NewNginxClient(httpClient, *scrapeURI)
  }, *nginxRetries, nginxRetryInterval.Duration)
  if err != nil {
  log.Fatalf("Could not create Nginx Client: %v", err)
@@ -225,3 +224,27 @@ func main() {
  log.Printf("NGINX Prometheus Exporter has successfully started")
  log.Fatal(http.ListenAndServe(*listenAddr, nil))
 }
+
+type userAgentRoundTripper struct {
+ agent string
+ rt http.RoundTripper
+}
+
+func (rt *userAgentRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+ req = cloneRequest(req)
+ req.Header.Set("User-Agent", rt.agent)
+ return rt.rt.RoundTrip(req)
+}
+func cloneRequest(req *http.Request) *http.Request {
+ r := new(http.Request)
+ *r = *req // shallow clone
+
+ // deep copy headers
+ r.Header = make(http.Header, len(req.Header))
+ for key, values := range req.Header {
+ newValues := make([]string, len(values))
+ copy(newValues, values)
+ r.Header[key] = newValues
+ }
+ return r
+}