Fix the issue that domain override has dependency on setting A365_OBS…

packages/agents-a365-observability/src/tracing/exporter/Agent365Exporter.ts

@@ -10,7 +10,7 @@ import { PowerPlatformApiDiscovery, ClusterCategory } from '@microsoft/agents-a3
 import { partitionByIdentity, parseIdentityKey, hexTraceId, hexSpanId, kindName, statusName } from './utils';
 import logger, { formatError } from '../../utils/logging';
 import { Agent365ExporterOptions } from './Agent365ExporterOptions';
-import { useCustomDomainForObservability, resolveAgent365Endpoint } from '../util';
+import { useCustomDomainForObservability, resolveAgent365Endpoint, getAgent365ObservabilityDomainOverride } from '../util';
 
 const DEFAULT_HTTP_TIMEOUT_SECONDS = 30000; // 30 seconds in ms
 const DEFAULT_MAX_RETRIES = 3;
@@ -144,25 +144,26 @@ export class Agent365Exporter implements SpanExporter {
 
     const payload = this.buildExportRequest(spans);
     const body = JSON.stringify(payload);
-
     const usingCustomServiceEndpoint = useCustomDomainForObservability();
-
     // Select endpoint path based on S2S flag
-    const endpointPath =
+    const endpointRelativePath =
       this.options.useS2SEndpoint
         ? `/maven/agent365/service/agents/${agentId}/traces`
         : `/maven/agent365/agents/${agentId}/traces`;
 
     let url: string;
-    if (usingCustomServiceEndpoint) {
+    const domainOverride = getAgent365ObservabilityDomainOverride();
+    if (domainOverride) {
+      url = `${domainOverride}${endpointRelativePath}?api-version=1`;
+    } else if (usingCustomServiceEndpoint) {
       const base = resolveAgent365Endpoint(this.options.clusterCategory as ClusterCategory);
-      url = `${base}${endpointPath}?api-version=1`;
+      url = `${base}${endpointRelativePath}?api-version=1`;
       logger.info(`[Agent365Exporter] Using custom domain endpoint: ${url}`);
     } else {
       // Default behavior: discover PPAPI gateway endpoint per-tenant
       const discovery = new PowerPlatformApiDiscovery(this.options.clusterCategory as ClusterCategory);
       const endpoint = discovery.getTenantIslandClusterEndpoint(tenantId);
-      url = `https://${endpoint}${endpointPath}?api-version=1`;
+      url = `https://${endpoint}${endpointRelativePath}?api-version=1`;
       logger.info(`[Agent365Exporter] Resolved endpoint: ${url}`);
     }
 

packages/agents-a365-observability/src/tracing/util.ts

@@ -36,23 +36,27 @@ export const useCustomDomainForObservability = (): boolean => {
 
 /**
  * Resolve the Agent365 service endpoint base URI for a given cluster category.
- *
- * By default this returns the production Agent365 endpoint. Internal development
- * and test clusters can override this by setting the
- * `A365_OBSERVABILITY_DOMAIN_OVERRIDE` environment variable. When set to a
- * non-empty value, that value is used as the base URI regardless of cluster category.
  */
 export function resolveAgent365Endpoint(clusterCategory: ClusterCategory): string {
-  const override = process.env.A365_OBSERVABILITY_DOMAIN_OVERRIDE;
-
-  if (override && override.trim().length > 0) {
-    // Normalize to avoid double slashes when concatenating paths
-    return override.trim().replace(/\/+$/, '');
-  }
-
   switch (clusterCategory) {
   case 'prod':
   default:
     return 'https://agent365.svc.cloud.microsoft';
   }
 }
+
+/**
+ * Get Agent365 Observability domain override.
+ * Internal development and test clusters can override this by setting the
+ * `A365_OBSERVABILITY_DOMAIN_OVERRIDE` environment variable. When set to a
+ * non-empty value, that value is used as the base URI regardless of cluster category. Otherwise, null is returned.
+ */
+export function getAgent365ObservabilityDomainOverride(): string | null{
+  const override = process.env.A365_OBSERVABILITY_DOMAIN_OVERRIDE;
+
+  if (override && override.trim().length > 0) {
+    // Normalize to avoid double slashes when concatenating paths
+    return override.trim().replace(/\/+$/, '');
+  } 
+  return null;
+}

tests/observability/core/agent365-exporter.test.ts

@@ -134,7 +134,7 @@ describe('Agent365Exporter', () => {
 
   it.each([
     {
-      description: 'set to non-empty value',
+      description: 'set to non-empty value and A365_OBSERVABILITY_USE_CUSTOM_DOMAIN is true',
       override: 'https://custom-observability.internal',
       expectedBaseUrl: 'https://custom-observability.internal'
     },
@@ -152,10 +152,16 @@ describe('Agent365Exporter', () => {
       description: 'unset (undefined)',
       override: undefined,
       expectedBaseUrl: 'https://agent365.svc.cloud.microsoft'
-    }
-  ])('uses correct domain when A365_OBSERVABILITY_DOMAIN_OVERRIDE is $description', async ({ override, expectedBaseUrl }) => {
+    },
+    {
+      description: 'set to non-empty value and A365_OBSERVABILITY_USE_CUSTOM_DOMAIN is false',
+      override: 'https://custom-observability.internal',
+      expectedBaseUrl: 'https://custom-observability.internal',
+      notUseCustomDomain: true
+    },
+  ])('uses correct domain when A365_OBSERVABILITY_DOMAIN_OVERRIDE is $description', async ({ override, expectedBaseUrl, notUseCustomDomain }) => {
     mockFetchSequence([200]);
-    process.env.A365_OBSERVABILITY_USE_CUSTOM_DOMAIN = 'true';
+    process.env.A365_OBSERVABILITY_USE_CUSTOM_DOMAIN = notUseCustomDomain ? 'false' : 'true';
 
     if (override !== undefined) {
       process.env.A365_OBSERVABILITY_DOMAIN_OVERRIDE = override as string;
@@ -184,7 +190,11 @@ describe('Agent365Exporter', () => {
     const headersArg = fetchCalls[0][1].headers as Record<string, string>;
 
     expect(urlArg).toBe(`${expectedBaseUrl}/maven/agent365/agents/${agentId}/traces?api-version=1`);
+    if(!notUseCustomDomain) {
     expect(headersArg['x-ms-tenant-id']).toBe(tenantId);
+    } else {
+    expect(headersArg['x-ms-tenant-id']).toBeUndefined();
+    }
     expect(headersArg['authorization']).toBe(`Bearer ${token}`);
   });