Web proxy configuration

This topic explains how to configure an SDK to connect to LaunchDarkly through a web proxy. This feature is available for client-side and server-side SDKs.

Overview

This topic explains how to configure an SDK to connect to LaunchDarkly through a web proxy. This feature is available for client-side and server-side SDKs.

Connecting to LaunchDarkly through a web proxy is not related to using LaunchDarkly’s Relay Proxy. To learn about LaunchDarkly’s Relay Proxy, read The Relay Proxy.

Connecting though a web proxy

If your organization requires that you use a web proxy to connect to external resources, you must configure your LaunchDarkly SDKs to connect through the proxy instead of connecting to LaunchDarkly directly.

Some proxies require authentication with a username and password, or with custom headers. Instructions on how to configure the SDK to send these parameters are in the SDK-specific sections.

In the following examples, the web proxy’s hostname is “my-proxy-host” and it uses port

8080. Substitute the appropriate values for your proxy. Details about each SDK’s configuration are available in the SDK-specific sections below:

• Client-side SDKs
• Server-side SDKs

Android, Flutter, iOS, and React Native support using a web proxy through their device operating systems (OS). You can use their onboard OS settings to configure a web proxy.

Client-side SDKs

This feature is available in the following client-side SDKs:

• .NET (client-side)
• C++ (client-side)

.NET (client-side)

Expand .NET (client-side) code sample

To configure the client-side .NET SDK to connect to LaunchDarkly through a web proxy:

C#

      var handler = new System.Net.Http.HttpClientHandler();
      handler.Proxy = new System.Net.WebProxy("http://my-proxy-host:8080");

      var config = Configuration
          .Builder("example-mobile-key", ConfigurationBuilder.AutoEnvAttributes.Enabled)
          .HttpMessageHandler(handler)
          .Build();

To configure the client-side .NET SDK to connect to LaunchDarkly through a web proxy with authentication:

C#

      var handler = new System.Net.Http.HttpClientHandler();
      var proxy = new System.Net.WebProxy("http://my-proxy-host:8080");
      var credentials = new System.Net.CredentialCache();
      credentials.Add(proxy.Address, "Basic",
          new NetworkCredential("username", "password"));
      proxy.Credentials = credentials;
      handler.Proxy = proxy;

      var config = Configuration
          .Builder("example-mobile-key", ConfigurationBuilder.AutoEnvAttributes.Enabled)
          .HttpMessageHandler(handler)
          .Build();

C++ (client-side)

Expand C++ (client-side) code sample

This feature is available in the client-side C++ SDK’s version 2.x only. It is not yet available in version 3.0.

To configure the client-side C/C++ SDK to connect to LaunchDarkly through a web proxy:

C SDK v2.x (native)

      struct LDConfig *config = LDConfigNew("example-mobile-key");
      LDConfigSetProxyURI(config, "https://web-proxy.domain.com:8080");

To configure the client-side C/C++ SDK to connect to LaunchDarkly through a web proxy with authentication:

C SDK v2.x (native)

      struct LDConfig *config = LDConfigNew("example-mobile-key");
      LDConfigSetProxyURI(config, "https://username:[e-mail]:8080");

Server-side SDKs

• .NET (server-side)
• Apex
• Go
• Java
• Node.js (server-side)
• Python
• Ruby
• Rust

.NET (server-side)

Expand .NET (server-side) code sample

To configure the server-side .NET SDK to connect to LaunchDarkly through a web proxy:

C#

      var proxy = new System.Net.WebProxy("http://my-proxy-host:8080");

      var config = Configuration.Builder("YOUR_SDK_KEY")
          .Http(Components.HttpConfiguration().Proxy(proxy))
          .Build();

To configure the server-side .NET SDK to connect to LaunchDarkly through a web proxy with authentication:

C#

      var proxyUri = new Uri("http://my-proxy-host:8080")
      var proxy = new System.Net.WebProxy(proxyUri);
      var credentials = new System.Net.CredentialCache();
      credentials.Add(proxy.Address, "Basic",
          new NetworkCredential("username", "password"));
      proxy.Credentials = credentials;

      var config = Configuration.Builder("YOUR_SDK_KEY")
          .Http(Components.HttpConfiguration().Proxy(proxy))
          .Build();

This example uses basic authentication. However, other options are supported: the proxy that you pass to the ConfigurationBuilder in the line .Http(Components.HttpConfiguration().Proxy(proxy)) can be any implementation of System.Net.IWebProxy. If you choose to use a different implementation of System.Net.IWebProxy, you may need to make corresponding configuration updates elsewhere in your system. For example, if you use Microsoft’s NTLM authentication, you may also need to enable System.Net.Security.UseManagedNtlm in your .NET project.

To learn more, read Http and HttpConfigurationBuilder.

Apex

Expand Apex code sample

The Apex bridge that provides and retrieves flag values is written in Go, and uses the default Go networking mechanisms. 

Go’s standard HTTP library recognizes the environment variables HTTP_PROXY and HTTPS_PROXY. If you set these variables, the SDK will connect through a web proxy at the URL you provide. Because the LaunchDarkly services have https: URLs, you use HTTPS_PROXY. If you are connecting to services at an insecure http: URL use HTTP_PROXY instead.

Here is an example:

Console

      export HTTPS_PROXY=https://my-proxy-host:8080

Go

Expand Go code sample

There are two ways to specify proxy server parameters in the Go SDK.

Go’s standard HTTP library recognizes the environment variables HTTP_PROXY and HTTPS_PROXY. If you set these variables, the SDK will connect through a web proxy at the URL you provide. Because the LaunchDarkly services have https: URLs, you use HTTPS_PROXY. If you are connecting to services at an insecure http: URL, such as a Relay Proxy instance, use HTTP_PROXY instead.

Here is an example:

Console

      export HTTPS_PROXY=https://my-proxy-host:8080

You can also specify a proxy programmatically through the SDK configuration:

Go SDK v6.0

      import (
          ld "github.com/launchdarkly/go-server-sdk/v6"
          "github.com/launchdarkly/go-server-sdk/v6/ldcomponents"
      )

      var config ld.Config
      config.HTTP = ldcomponents.HTTPConfiguration().
          ProxyURL("https://my-proxy-host:8080")

Java

Expand Java code sample

To configure the Java SDK to connect to LaunchDarkly through a web proxy:

Java

      LDConfig config = new LDConfig.Builder()
        .http(Components.httpConfiguration().proxyHostAndPort("my-proxy-host", 8080))
        .build();

To configure the Java SDK to connect to LaunchDarkly through a web proxy with authentication:

Java

      LDConfig config = new LDConfig.Builder()
        .http(Components.httpConfiguration()
          .proxyHostAndPort("my-proxy-host", 8080)
          .proxyAuth(Components.httpBasicAuthentication("username", "password")))
        .build();

Node.js (server-side)

Expand Node.js (server-side) code sample

To configure the server-side Node.js SDK to connect to LaunchDarkly through a web proxy:

Node.js SDK v8.x (TypeScript)

      import { LDOptions } from '@launchdarkly/node-server-sdk';

      const options: LDOptions = {
        proxyOptions: {
            host: 'your-proxy-host',
            port: 8080,
            scheme: 'https'
          }
      };

To configure the server-side Node.js SDK to connect to LaunchDarkly through a web proxy with authentication:

Node.js SDK v8.x (TypeScript)

      import { LDOptions } from '@launchdarkly/node-server-sdk';

      const options: LDOptions = {
        proxyOptions: {
            host: 'your-proxy-host',
            port: 8080,
            scheme: 'https',
            auth: 'username:password'
          }
      };

To learn more, read proxyOptions.

Python

Expand Python code sample

There are two ways to specify proxy server parameters in the Python SDK.

Python’s standard HTTP library recognizes the environment variables HTTP_PROXY and HTTPS_PROXY. If you set these variables, the SDK will connect through a web proxy at the URL you provide. Because the LaunchDarkly services have https: URLs, you use HTTPS_PROXY. If you are connecting to services at an insecure http: URL, such as a Relay Proxy instance, use HTTP_PROXY instead.

How to set the HTTPS_PROXY environment variable on Mac/Linux and Windows systems:

Console

      export HTTPS_PROXY=https://my-proxy-host:8080

Or it can be set from within Python:

Python

      os.environ["HTTPS_PROXY"] = "https://my-proxy-host:8080"

Ruby

Expand Ruby code sample

There are two ways to specify proxy server parameters in the Ruby SDK.

Ruby’s standard HTTP library recognizes the environment variables HTTP_PROXY and HTTPS_PROXY. If you set these variables, the SDK will connect through a web proxy at the URL you provide. Because the LaunchDarkly services have https: URLs, you use HTTPS_PROXY. If you are connecting to services at an insecure http: URL, such as a Relay Proxy instance, use HTTP_PROXY instead.

To configure the Ruby SDK to connect to LaunchDarkly through a web proxy:

Console

      export HTTPS_PROXY=https://my-proxy-host:8080

Or it can be set from within Ruby:

Ruby

      ENV['HTTPS_PROXY'] = 'https://my-proxy-host:8080'

Rust

Expand Rust code sample

This feature is available in the Rust SDK’s version 3.0 and later.

Starting in version 3.0, the Rust SDK’s transport layer automatically detects proxy settings from environment variables. The SDK supports HTTP_PROXY, HTTPS_PROXY, and NO_PROXY. Lowercase variants take precedence over uppercase.

The proxy routing behavior is:

• Both HTTP_PROXY and HTTPS_PROXY set: HTTP requests use HTTP_PROXY, HTTPS requests use HTTPS_PROXY.
• Only HTTP_PROXY set: All requests, including HTTPS, route through HTTP_PROXY.
• Only HTTPS_PROXY set: Only HTTPS requests use the proxy. HTTP requests connect directly.
• Neither set: All requests connect directly with no proxy.

Use NO_PROXY to bypass the proxy for specific hosts. It accepts a comma-separated list of host names or * to disable the proxy for all hosts.

Here is an example:

Console

      export HTTPS_PROXY=https://my-proxy-host:8080

To configure the Rust SDK to connect to LaunchDarkly through a web proxy with authentication, include the credentials in the proxy URL:

Console

      export HTTPS_PROXY="https://username:password@my-proxy-host:8080"

You can also configure a proxy programmatically, or disable proxy support entirely:

Rust

      use launchdarkly_sdk_transport::HyperTransport;

      // Use a custom proxy URL
      let transport = HyperTransport::builder()
          .proxy_url("https://my-proxy-host:8080".to_string())
          .build_http()?;

      // Disable proxy completely
      let transport = HyperTransport::builder()
          .disable_proxy()
          .build_http()?;