DatadogExporter: Add supports for HTTP_PROXY, HTTPS_PROXY and NO_PROXY for logs. (#38076)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

Add supports for `HTTP_PROXY`, `HTTPS_PROXY` and `NO_PROXY` for logs in
`datadogexporter`.

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue

#36292

Fixes


<!--Describe what testing was performed and which tests were added.-->
#### Testing

- Setup a local proxy
- Set `HTTP_PROXY` to the local proxy address
- Check proxy didn't receive any payloads when sending logs without the
changes from this PR
- Check proxy receive a logs payload with the change from this PR

<!--Describe the documentation added.-->
#### Documentation

<!--Please delete paragraphs that you did not use before submitting.-->

Author: ogaca-dd

.chloggen/olivierg_hhtp-proxy-env.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: bug_fix
+
+# 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: Add supports for HTTP_PROXY, HTTPS_PROXY and NO_PROXY for logs
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [36292]
+
+# (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/agent_components.go

@@ -12,6 +12,7 @@ import (
 	pkgconfigmodel "github.com/DataDog/datadog-agent/pkg/config/model"
 	pkgconfigsetup "github.com/DataDog/datadog-agent/pkg/config/setup"
 	"go.opentelemetry.io/collector/component"
+	"golang.org/x/net/http/httpproxy"
 
 	pkgdatadog "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/datadog"
 )
@@ -52,5 +53,22 @@ func newConfigComponent(set component.TelemetrySettings, cfg *Config) coreconfig
 	// add logs config pipelines config value, see https://github.com/DataDog/datadog-agent/pull/31190
 	logsPipelines := min(4, runtime.GOMAXPROCS(0))
 	pkgconfig.Set("logs_config.pipelines", logsPipelines, pkgconfigmodel.SourceDefault)
+	setProxyFromEnv(pkgconfig)
+
 	return pkgconfig
 }
+
+func setProxyFromEnv(config pkgconfigmodel.Config) {
+	proxyConfig := httpproxy.FromEnvironment()
+	config.Set("proxy.http", proxyConfig.HTTPProxy, pkgconfigmodel.SourceEnvVar)
+	config.Set("proxy.https", proxyConfig.HTTPSProxy, pkgconfigmodel.SourceEnvVar)
+
+	// If this is set to an empty []string, viper will have a type conflict when merging
+	// this config during secrets resolution. It unmarshals empty yaml lists to type
+	// []interface{}, which will then conflict with type []string and fail to merge.
+	var noProxy []any
+	for _, v := range strings.Split(proxyConfig.NoProxy, ",") {
+		noProxy = append(noProxy, v)
+	}
+	config.Set("proxy.no_proxy", noProxy, pkgconfigmodel.SourceEnvVar)
+}

exporter/datadogexporter/go.mod

@@ -95,6 +95,7 @@ require (
 	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/datadog v0.120.1
 	go.opentelemetry.io/collector/component/componenttest v0.120.1-0.20250224010654-18e18b21da7a
 	go.opentelemetry.io/collector/exporter/exportertest v0.120.1-0.20250224010654-18e18b21da7a
+	golang.org/x/net v0.35.0
 )
 
 require (
@@ -411,7 +412,6 @@ require (
 	golang.org/x/crypto v0.33.0 // indirect
 	golang.org/x/exp v0.0.0-20250210185358-939b2ce775ac // indirect
 	golang.org/x/mod v0.23.0 // indirect
-	golang.org/x/net v0.35.0 // indirect
 	golang.org/x/oauth2 v0.26.0 // indirect
 	golang.org/x/sync v0.11.0 // indirect
 	golang.org/x/sys v0.30.0 // indirect