Using HTTP Proxy

Signed-off-by: Maksim Paskal <[email protected]>

pkg/events/events.go

@@ -34,7 +34,7 @@ const (
 )
 
 var httpClient = &http.Client{
-	Transport: metrics.NewInstrumenter("events", false).InstrumentedRoundTripper(),
+	Transport: metrics.NewInstrumenter("events").InstrumentedRoundTripper(),
 }
 
 type Reader struct {

pkg/metrics/metrics.go

@@ -33,17 +33,35 @@ const namespace = "aks_node_termination_handler"
 type Instrumenter struct {
 	subsystemIdentifier string
 	insecureSkipVerify  bool
+	useProxyFromEnv     bool
 }
 
 // New creates a new Instrumenter. The subsystemIdentifier will be used as part of
 // the metric names (e.g. http_<identifier>_requests_total).
-func NewInstrumenter(subsystemIdentifier string, insecureSkipVerify bool) *Instrumenter {
+func NewInstrumenter(subsystemIdentifier string) *Instrumenter {
 	return &Instrumenter{
 		subsystemIdentifier: subsystemIdentifier,
-		insecureSkipVerify:  insecureSkipVerify,
 	}
 }
 
+type InstrumenterWith string
+
+const (
+	ProxyFromEnv       InstrumenterWith = "proxy_from_env"
+	InsecureSkipVerify InstrumenterWith = "insecure_skip_verify"
+)
+
+func (i *Instrumenter) With(options InstrumenterWith) *Instrumenter {
+	switch options {
+	case InsecureSkipVerify:
+		i.insecureSkipVerify = true
+	case ProxyFromEnv:
+		i.useProxyFromEnv = true
+	}
+
+	return i
+}
+
 // InstrumentedRoundTripper returns an instrumented round tripper.
 func (i *Instrumenter) InstrumentedRoundTripper() http.RoundTripper {
 	inFlightRequestsGauge := promauto.NewGauge(prometheus.GaugeOpts{
@@ -71,15 +89,19 @@ func (i *Instrumenter) InstrumentedRoundTripper() http.RoundTripper {
 		[]string{"method"},
 	)
 
+	defaultTransport := &http.Transport{
+		TLSClientConfig: &tls.Config{
+			InsecureSkipVerify: i.insecureSkipVerify, //nolint:gosec
+		},
+	}
+
+	if i.useProxyFromEnv {
+		defaultTransport.Proxy = http.ProxyFromEnvironment
+	}
+
 	return promhttp.InstrumentRoundTripperInFlight(inFlightRequestsGauge,
 		promhttp.InstrumentRoundTripperDuration(requestLatencyHistogram,
-			i.instrumentRoundTripperEndpoint(requestsPerEndpointCounter,
-				&http.Transport{
-					TLSClientConfig: &tls.Config{
-						InsecureSkipVerify: i.insecureSkipVerify, //nolint:gosec
-					},
-				},
-			),
+			i.instrumentRoundTripperEndpoint(requestsPerEndpointCounter, defaultTransport),
 		),
 	)
 }

pkg/metrics/metrics_test.go

@@ -77,7 +77,7 @@ func TestKubernetesMetrics(t *testing.T) {
 func TestInstrumenter(t *testing.T) {
 	t.Parallel()
 
-	instrumenter := metrics.NewInstrumenter("test", false)
+	instrumenter := metrics.NewInstrumenter("test")
 
 	r, err := instrumenter.InstrumentedRoundTripper().RoundTrip(httptest.NewRequest(http.MethodGet, ts.URL, nil))
 	if err != nil {

pkg/webhook/webhook.go

@@ -27,7 +27,10 @@ import (
 )
 
 var client = &http.Client{
-	Transport: metrics.NewInstrumenter("webhook", true).InstrumentedRoundTripper(),
+	Transport: metrics.NewInstrumenter("webhook").
+		With(metrics.InsecureSkipVerify).
+		With(metrics.ProxyFromEnv).
+		InstrumentedRoundTripper(),
 }
 
 var errHTTPNotOK = errors.New("http result not OK")