add support for proxy

config/confighttp/confighttp.go

@@ -9,6 +9,7 @@
 	"io"
 	"net"
 	"net/http"
+	"net/url"
 	"time"
 
 	"github.com/rs/cors"
@@ -32,6 +33,9 @@
 	// The target URL to send data to (e.g.: http://some.url:9411/v1/traces).
 	Endpoint string `mapstructure:"endpoint"`
 
+	// ProxyURL setting for the collector
+	ProxyURL string `mapstructure:"proxy_url"`
+
 	// TLSSetting struct exposes TLS client configuration.
 	TLSSetting configtls.TLSClientSetting `mapstructure:"tls"`
 
@@ -132,6 +136,15 @@
 		transport.IdleConnTimeout = *hcs.IdleConnTimeout
 	}
 
+	// Setting the Proxy URL
+	if hcs.ProxyURL != "" {
+		proxyURL, err := url.Parse(hcs.ProxyURL)
+		if err != nil {
+			return nil, err
+		}
+		transport.Proxy = http.ProxyURL(proxyURL)
+	}
+
 	transport.DisableKeepAlives = hcs.DisableKeepAlives
 
 	clientTransport := (http.RoundTripper)(transport)

config/confighttp/confighttp_test.go

@@ -208,6 +208,48 @@ func TestDefaultHTTPClientSettings(t *testing.T) {
 	assert.EqualValues(t, 90*time.Second, *httpClientSettings.IdleConnTimeout)
 }
 
+func TestProxyURL(t *testing.T) {
+	testCases := []struct {
+		desc        string
+		proxyURL    string
+		expectedURL *url.URL
+	}{
+		{
+			desc:        "default config",
+			expectedURL: nil,
+		},
+		{
+			desc:        "proxy is set",
+			proxyURL:    "http://proxy.example.com:8080",
+			expectedURL: &url.URL{Scheme: "http", Host: "proxy.example.com:8080"},
+		},
+	}
+	for _, tC := range testCases {
+		t.Run(tC.desc, func(t *testing.T) {
+			s := NewDefaultHTTPClientSettings()
+			s.ProxyURL = tC.proxyURL
+
+			tt := componenttest.NewNopTelemetrySettings()
+			tt.TracerProvider = nil
+			client, err := s.ToClient(componenttest.NewNopHost(), tt)
+			require.NoError(t, err)
+
+			transport := client.Transport.(*http.Transport)
+			require.NotNil(t, transport.Proxy)
+
+			url, err := transport.Proxy(&http.Request{URL: &url.URL{Scheme: "http", Host: "example.com"}})
+			require.NoError(t, err)
+
+			if tC.expectedURL == nil {
+				assert.Nil(t, url)
+			} else {
+				require.NotNil(t, url)
+				assert.Equal(t, tC.expectedURL, url)
+			}
+		})
+	}
+}
+
 func TestHTTPClientSettingsError(t *testing.T) {
 	host := &mockHost{
 		ext: map[component.ID]component.Component{},