Adding Proxy support for Datadog Exporter

.chloggen/proxyurl-for-ddexp.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: datadogexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: The Datadog Exporter now supports the `proxy_url` parameter to configure an HTTP proxy to use when sending telemetry to Datadog.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [33316]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

exporter/datadogexporter/config.go

@@ -516,9 +516,6 @@ func validateClientConfig(cfg confighttp.ClientConfig) error {
 	if cfg.Compression != "" {
 		unsupported = append(unsupported, "compression")
 	}
-	if cfg.ProxyURL != "" {
-		unsupported = append(unsupported, "proxy_url")
-	}
 	if cfg.Headers != nil {
 		unsupported = append(unsupported, "headers")
 	}

exporter/datadogexporter/config_test.go

@@ -153,14 +153,13 @@ func TestValidate(t *testing.T) {
 				ClientConfig: confighttp.ClientConfig{
 					Endpoint:             "endpoint",
 					Compression:          "gzip",
-					ProxyURL:             "proxy",
 					Auth:                 &auth,
 					Headers:              map[string]configopaque.String{"key": "val"},
 					HTTP2ReadIdleTimeout: 250,
 					HTTP2PingTimeout:     200,
 				},
 			},
-			err: "these confighttp client configs are currently not respected by Datadog exporter: auth, endpoint, compression, proxy_url, headers, http2_read_idle_timeout, http2_ping_timeout",
+			err: "these confighttp client configs are currently not respected by Datadog exporter: auth, endpoint, compression, headers, http2_read_idle_timeout, http2_ping_timeout",
 		},
 	}
 	for _, testInstance := range tests {

exporter/datadogexporter/internal/clientutil/http.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"net/url"
 	"time"
 
 	"go.opentelemetry.io/collector/component"
@@ -29,8 +30,14 @@ var (
 
 // NewHTTPClient returns a http.Client configured with a subset of the confighttp.ClientConfig options.
 func NewHTTPClient(hcs confighttp.ClientConfig) *http.Client {
+	// If the ProxyURL field in the configuration is set, the HTTP client will use the proxy.
+	// Otherwise, the HTTP client will use the system's proxy settings.
+	httpProxy := http.ProxyFromEnvironment
+	if parsedProxyURL, err := url.Parse(hcs.ProxyURL); err == nil && parsedProxyURL.Scheme != "" {
+		httpProxy = http.ProxyURL(parsedProxyURL)
+	}
 	transport := http.Transport{
-		Proxy: http.ProxyFromEnvironment,
+		Proxy: httpProxy,
 		// Default values consistent with https://github.com/DataDog/datadog-agent/blob/f9ae7f4b842f83b23b2dfe3f15d31f9e6b12e857/pkg/util/http/transport.go#L91-L106
 		DialContext: (&net.Dialer{
 			Timeout: 30 * time.Second,

exporter/datadogexporter/internal/clientutil/http_test.go

@@ -6,6 +6,7 @@ package clientutil // import "github.com/open-telemetry/opentelemetry-collector-
 import (
 	"crypto/tls"
 	"net/http"
+	"net/url"
 	"testing"
 	"time"
 
@@ -60,10 +61,10 @@ func TestNewHTTPClient(t *testing.T) {
 		MaxConnsPerHost:     &maxConnPerHost,
 		DisableKeepAlives:   true,
 		TLSSetting:          configtls.ClientConfig{InsecureSkipVerify: true},
+		ProxyURL:            "proxy",
 
 		// The rest are ignored
 		Endpoint:             "endpoint",
-		ProxyURL:             "proxy",
 		Compression:          configcompression.TypeSnappy,
 		HTTP2ReadIdleTimeout: 15 * time.Second,
 		HTTP2PingTimeout:     20 * time.Second,
@@ -90,6 +91,72 @@ func TestNewHTTPClient(t *testing.T) {
 		t.Errorf("Mismatched transports -want +got %s", diff)
 	}
 	assert.Equal(t, 10*time.Second, client2.Timeout)
+
+	// Checking that the client config can receive ProxyUrl and
+	// it will be passed to the http client.
+	hcsForC3 := confighttp.ClientConfig{
+		ReadBufferSize:      100,
+		WriteBufferSize:     200,
+		Timeout:             10 * time.Second,
+		IdleConnTimeout:     &idleConnTimeout,
+		MaxIdleConns:        &maxIdleConn,
+		MaxIdleConnsPerHost: &maxIdleConnPerHost,
+		MaxConnsPerHost:     &maxConnPerHost,
+		DisableKeepAlives:   true,
+		TLSSetting:          configtls.ClientConfig{InsecureSkipVerify: true},
+		ProxyURL:            "http://datadog-proxy.myorganization.com:3128",
+
+		// The rest are ignored
+		Endpoint:             "endpoint",
+		Compression:          configcompression.TypeSnappy,
+		HTTP2ReadIdleTimeout: 15 * time.Second,
+		HTTP2PingTimeout:     20 * time.Second,
+	}
+	ddURL, _ := url.Parse("https://datadoghq.com")
+	parsedProxy, _ := url.Parse("http://datadog-proxy.myorganization.com:3128")
+	client3 := NewHTTPClient(hcsForC3)
+	tr3 := client3.Transport.(*http.Transport)
+	url3, _ := tr3.Proxy(&http.Request{
+		URL: ddURL,
+	})
+	assert.Equal(t, url3, parsedProxy)
+
+	// Checking that the client config can receive ProxyUrl to override the
+	// environment variable.
+	t.Setenv("HTTPS_PROXY", "http://datadog-proxy-from-env.myorganization.com:3128")
+	client4 := NewHTTPClient(hcsForC3)
+	tr4 := client4.Transport.(*http.Transport)
+	url4, _ := tr4.Proxy(&http.Request{
+		URL: ddURL,
+	})
+	assert.Equal(t, url4, parsedProxy)
+
+	// Checking that in the absence of ProxyUrl in the client config, the
+	// environment variable is used for the http proxy.
+	hcsForC5 := confighttp.ClientConfig{
+		ReadBufferSize:      100,
+		WriteBufferSize:     200,
+		Timeout:             10 * time.Second,
+		IdleConnTimeout:     &idleConnTimeout,
+		MaxIdleConns:        &maxIdleConn,
+		MaxIdleConnsPerHost: &maxIdleConnPerHost,
+		MaxConnsPerHost:     &maxConnPerHost,
+		DisableKeepAlives:   true,
+		TLSSetting:          configtls.ClientConfig{InsecureSkipVerify: true},
+
+		// The rest are ignored
+		Endpoint:             "endpoint",
+		Compression:          configcompression.TypeSnappy,
+		HTTP2ReadIdleTimeout: 15 * time.Second,
+		HTTP2PingTimeout:     20 * time.Second,
+	}
+	parsedEnvProxy, _ := url.Parse("http://datadog-proxy-from-env.myorganization.com:3128")
+	client5 := NewHTTPClient(hcsForC5)
+	tr5 := client5.Transport.(*http.Transport)
+	url5, _ := tr5.Proxy(&http.Request{
+		URL: ddURL,
+	})
+	assert.Equal(t, url5, parsedEnvProxy)
 }
 
 func TestUserAgent(t *testing.T) {