Add proxy support for corporate environments (#209)

* Add proxy support for corporate environments

- Created proxy-config utility to configure undici ProxyAgent
- Added support for https_proxy, HTTPS_PROXY, http_proxy, HTTP_PROXY, no_proxy, and NO_PROXY environment variables
- Proxy is configured early in startup process before any HTTP requests
- Added comprehensive test coverage for proxy configuration
- Updated README.md with proxy environment variable documentation
- Updated CHANGELOG.md to document new feature

Co-authored-by: manoharnv <[email protected]>

* Address code review feedback

- Remove unnecessary log message when no proxy is configured
- Clarify no_proxy limitation in code comments and README
- Update .env.template with proxy configuration examples

Co-authored-by: manoharnv <[email protected]>

* Update README.md

Fixing as per review comment.
placing the proxy configuration at the right place.

* Remove unused shouldBypassProxy function and all references

Co-authored-by: manoharnv <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: manoharnv <[email protected]>

Author: manoharnv

.env.template

@@ -1,3 +1,7 @@
 OAUTH_CLIENT_ID=dt0s02.SAMPLE
 OAUTH_CLIENT_SECRET=dt0s02.SAMPLE.ABCD1234
 DT_ENVIRONMENT=https://abcd1234.apps.dynatrace.com
+
+# Proxy configuration (optional - for corporate environments)
+# HTTPS_PROXY=http://proxy.example.com:8080
+# NO_PROXY=localhost,127.0.0.1,.local

CHANGELOG.md

@@ -17,6 +17,15 @@
 
 - Fixed an issue where disabling telemetry with `DT_MCP_DISABLE_TELEMETRY=true` would show a stack trace instead of a concise message.
 
+### Proxy Support
+
+- Added support for system proxy configuration via environment variables (`https_proxy`, `HTTPS_PROXY`, `http_proxy`, `HTTP_PROXY`, `no_proxy`, `NO_PROXY`)
+- The MCP server now honors corporate proxy settings for all HTTP requests to Dynatrace environments
+
+### Other Changes
+
+- Removed unused `shouldBypassProxy` function from proxy configuration utilities
+
 ## 0.9.2
 
 - Improved error handling when initializing the connection for the first time

README.md

@@ -298,6 +298,24 @@ In addition, depending on the features you use, the following variables can be c
 
 - `SLACK_CONNECTION_ID` (string) - connection ID of a [Slack Connection](https://docs.dynatrace.com/docs/analyze-explore-automate/workflows/actions/slack)
 
+### Proxy Configuration
+
+The MCP server honors system proxy settings for corporate environments:
+
+- `https_proxy` or `HTTPS_PROXY` (optional, string, e.g., `http://proxy.example.com:8080`) - Proxy server URL for HTTPS requests
+- `http_proxy` or `HTTP_PROXY` (optional, string, e.g., `http://proxy.example.com:8080`) - Proxy server URL for HTTP requests
+- `no_proxy` or `NO_PROXY` (optional, string, e.g., `localhost,127.0.0.1,.local`) - Comma-separated list of hostnames or domains that should bypass the proxy
+
+**Note:** The `no_proxy` environment variable is currently logged for informational purposes but not fully enforced by the underlying HTTP client. If you need to bypass the proxy for specific hosts, consider configuring your proxy server to handle these exclusions.
+
+Example configuration with proxy:
+
+```bash
+export HTTPS_PROXY=http://proxy.company.com:8080
+export NO_PROXY=localhost,127.0.0.1,.company.local
+export DT_ENVIRONMENT=https://abc12345.apps.dynatrace.com
+```
+
 ### Scopes for Authentication
 
 Depending on the features you are using, the following scopes are needed:

src/index.ts

@@ -47,6 +47,7 @@ import { createTelemetry, Telemetry } from './utils/telemetry-openkit';
 import { getEntityTypeFromId } from './utils/dynatrace-entity-types';
 import { resetGrailBudgetTracker, getGrailBudgetTracker } from './utils/grail-budget-tracker';
 import { handleClientRequestError } from './utils/dynatrace-connection-utils';
+import { configureProxyFromEnvironment } from './utils/proxy-config';
 
 // Load environment variables from .env file if available, and suppress warnings/logging to stdio
 // as it breaks MCP communication when using stdio transport
@@ -110,6 +111,9 @@ const allRequiredScopes = scopesBase.concat([
 const main = async () => {
   console.error(`Initializing Dynatrace MCP Server v${getPackageJsonVersion()}...`);
 
+  // Configure proxy from environment variables early in the startup process
+  configureProxyFromEnvironment();
+
   // read Environment variables
   let dynatraceEnv: DynatraceEnv;
   try {

src/utils/proxy-config.test.ts

@@ -0,0 +1,103 @@
+import { configureProxyFromEnvironment } from './proxy-config';
+
+// Mock undici
+jest.mock('undici', () => ({
+  ProxyAgent: jest.fn(),
+  setGlobalDispatcher: jest.fn(),
+  getGlobalDispatcher: jest.fn(),
+}));
+
+import { ProxyAgent, setGlobalDispatcher } from 'undici';
+
+describe('proxy-config', () => {
+  let originalEnv: NodeJS.ProcessEnv;
+
+  beforeEach(() => {
+    // Save original environment
+    originalEnv = { ...process.env };
+
+    // Clear all proxy-related env vars
+    delete process.env.https_proxy;
+    delete process.env.HTTPS_PROXY;
+    delete process.env.http_proxy;
+    delete process.env.HTTP_PROXY;
+    delete process.env.no_proxy;
+    delete process.env.NO_PROXY;
+
+    // Clear mocks
+    jest.clearAllMocks();
+  });
+
+  afterEach(() => {
+    // Restore original environment
+    process.env = originalEnv;
+  });
+
+  describe('configureProxyFromEnvironment', () => {
+    it('should configure proxy when HTTPS_PROXY is set', () => {
+      process.env.HTTPS_PROXY = 'http://proxy.example.com:8080';
+
+      configureProxyFromEnvironment();
+
+      expect(ProxyAgent).toHaveBeenCalledWith({
+        uri: 'http://proxy.example.com:8080',
+      });
+      expect(setGlobalDispatcher).toHaveBeenCalled();
+    });
+
+    it('should configure proxy when https_proxy is set (lowercase)', () => {
+      process.env.https_proxy = 'http://proxy.example.com:8080';
+
+      configureProxyFromEnvironment();
+
+      expect(ProxyAgent).toHaveBeenCalledWith({
+        uri: 'http://proxy.example.com:8080',
+      });
+      expect(setGlobalDispatcher).toHaveBeenCalled();
+    });
+
+    it('should prefer HTTPS_PROXY over HTTP_PROXY', () => {
+      process.env.HTTPS_PROXY = 'http://https-proxy.example.com:8443';
+      process.env.HTTP_PROXY = 'http://http-proxy.example.com:8080';
+
+      configureProxyFromEnvironment();
+
+      expect(ProxyAgent).toHaveBeenCalledWith({
+        uri: 'http://https-proxy.example.com:8443',
+      });
+    });
+
+    it('should fall back to HTTP_PROXY if HTTPS_PROXY is not set', () => {
+      process.env.HTTP_PROXY = 'http://proxy.example.com:8080';
+
+      configureProxyFromEnvironment();
+
+      expect(ProxyAgent).toHaveBeenCalledWith({
+        uri: 'http://proxy.example.com:8080',
+      });
+    });
+
+    it('should not configure proxy when no proxy env vars are set', () => {
+      configureProxyFromEnvironment();
+
+      expect(ProxyAgent).not.toHaveBeenCalled();
+      expect(setGlobalDispatcher).not.toHaveBeenCalled();
+    });
+
+    it('should handle errors gracefully', () => {
+      process.env.HTTPS_PROXY = 'http://proxy.example.com:8080';
+      const mockProxyAgent = ProxyAgent as unknown as jest.Mock;
+      mockProxyAgent.mockImplementation(() => {
+        throw new Error('ProxyAgent error');
+      });
+
+      // Should not throw
+      expect(() => configureProxyFromEnvironment()).not.toThrow();
+
+      // Should still attempt to create ProxyAgent
+      expect(ProxyAgent).toHaveBeenCalled();
+      // Should not set dispatcher if ProxyAgent creation fails
+      expect(setGlobalDispatcher).not.toHaveBeenCalled();
+    });
+  });
+});

src/utils/proxy-config.ts

@@ -0,0 +1,56 @@
+import { ProxyAgent, setGlobalDispatcher, getGlobalDispatcher } from 'undici';
+
+/**
+ * Parse and configure system proxy settings from environment variables.
+ * Supports https_proxy, HTTPS_PROXY, http_proxy, HTTP_PROXY, no_proxy, and NO_PROXY.
+ *
+ * This function should be called early in the application lifecycle to ensure
+ * all HTTP requests honor the system proxy settings.
+ */
+export function configureProxyFromEnvironment(): void {
+  // Check for proxy environment variables (case-insensitive)
+  const httpsProxy = process.env.https_proxy || process.env.HTTPS_PROXY;
+  const httpProxy = process.env.http_proxy || process.env.HTTP_PROXY;
+  const noProxy = process.env.no_proxy || process.env.NO_PROXY;
+
+  // Determine which proxy to use (prefer HTTPS proxy for HTTPS requests)
+  const proxyUrl = httpsProxy || httpProxy;
+
+  if (!proxyUrl) {
+    // No proxy configured, nothing to do
+    return;
+  }
+
+  try {
+    console.error(`Configuring proxy from environment: ${proxyUrl}`);
+
+    // Parse no_proxy list if provided
+    let noProxyHosts: string[] = [];
+    if (noProxy) {
+      // Split by comma and trim whitespace
+      noProxyHosts = noProxy
+        .split(',')
+        .map((host) => host.trim())
+        .filter((host) => host.length > 0);
+      console.error(`No proxy hosts configured: ${noProxyHosts.join(', ')}`);
+    }
+
+    // Create ProxyAgent with the configured proxy URL
+    // Note: undici's ProxyAgent doesn't have built-in no_proxy support.
+    // The no_proxy environment variable is logged for informational purposes,
+    // but the ProxyAgent will route all requests through the proxy.
+    // If no_proxy support is critical for your use case, you may need to
+    // configure your proxy server to handle no_proxy exclusions.
+    const proxyAgent = new ProxyAgent({
+      uri: proxyUrl,
+    });
+
+    // Set the global dispatcher for undici (affects global fetch)
+    setGlobalDispatcher(proxyAgent);
+
+    console.error(`✅ Proxy configured successfully: ${proxyUrl}`);
+  } catch (error) {
+    console.error(`⚠️ Failed to configure proxy: ${error instanceof Error ? error.message : String(error)}`);
+    console.error('Continuing without proxy configuration.');
+  }
+}