From d3f6d09b65a7878cf18b22eeda826149279daa71 Mon Sep 17 00:00:00 2001
From: Vishwesh Bankwar <vishweshbankwar@users.noreply.github.com>
Date: Tue, 21 Feb 2023 09:59:48 -0800
Subject: [PATCH] [Azure.ResourceDetectors] Add appservice service.instance.id
 (#1012)

---
 .../AppServiceResourceDetector.cs             | 36 +++++++++++--------
 .../AzureResourceDetectorTests.cs             | 25 ++++++-------
 2 files changed, 34 insertions(+), 27 deletions(-)

diff --git a/src/OpenTelemetry.ResourceDetectors.Azure/AppServiceResourceDetector.cs b/src/OpenTelemetry.ResourceDetectors.Azure/AppServiceResourceDetector.cs
index e9ed7bbf43..3ab8352c10 100644
--- a/src/OpenTelemetry.ResourceDetectors.Azure/AppServiceResourceDetector.cs
+++ b/src/OpenTelemetry.ResourceDetectors.Azure/AppServiceResourceDetector.cs
@@ -29,29 +29,35 @@ public sealed class AppServiceResourceDetector : IResourceDetector
     /// <inheritdoc/>
     public Resource? Detect()
     {
-        string? serviceName = null;
+        List<KeyValuePair<string, object>>? attributeList = null;
+
         try
         {
+            string? serviceName = null;
+            string? serviceInstanceId = null;
+
             // https://learn.microsoft.com/azure/app-service/reference-app-settings?tabs=kudu%2Cdotnet#app-environment
             serviceName = Environment.GetEnvironmentVariable("WEBSITE_SITE_NAME");
-        }
-        catch
-        {
-            // TODO: log exception.
-        }
-
-        List<KeyValuePair<string, object>>? attributeList = null;
+            serviceInstanceId = Environment.GetEnvironmentVariable("WEBSITE_INSTANCE_ID");
+            if (serviceName != null)
+            {
+                attributeList = new();
 
-        if (serviceName != null)
-        {
-            attributeList = new();
+                attributeList.Add(new KeyValuePair<string, object>(ResourceSemanticConventions.AttributeServiceName, serviceName));
 
-            attributeList.Add(new KeyValuePair<string, object>(ResourceSemanticConventions.AttributeServiceName, serviceName));
-
-            // TODO: Add other attributes e.g. service.instance.id
+                if (serviceInstanceId != null)
+                {
+                    attributeList.Add(new KeyValuePair<string, object>(ResourceSemanticConventions.AttributeServiceInstance, serviceInstanceId));
+                }
+            }
+            else
+            {
+                return Resource.Empty;
+            }
         }
-        else
+        catch
         {
+            // TODO: log exception.
             return Resource.Empty;
         }
 
diff --git a/test/OpenTelemetry.ResourceDetectors.Azure.Tests/AzureResourceDetectorTests.cs b/test/OpenTelemetry.ResourceDetectors.Azure.Tests/AzureResourceDetectorTests.cs
index a785f9b133..2e91877be4 100644
--- a/test/OpenTelemetry.ResourceDetectors.Azure.Tests/AzureResourceDetectorTests.cs
+++ b/test/OpenTelemetry.ResourceDetectors.Azure.Tests/AzureResourceDetectorTests.cs
@@ -22,22 +22,17 @@
 
 namespace OpenTelemetry.ResourceDetectors.Azure.Tests;
 
-public class AzureResourceDetectorTests
+public class AzureResourceDetectorTests : IDisposable
 {
     [Fact]
     public void AppServiceResourceDetectorReturnsResourceWithAttributes()
     {
-        try
-        {
-            Environment.SetEnvironmentVariable("WEBSITE_SITE_NAME", "AzureAppService");
-            var resource = ResourceBuilder.CreateEmpty().AddDetector(new AppServiceResourceDetector()).Build();
-            Assert.NotNull(resource);
-            Assert.Contains(new KeyValuePair<string, object>(ResourceSemanticConventions.AttributeServiceName, "AzureAppService"), resource.Attributes);
-        }
-        finally
-        {
-            Environment.SetEnvironmentVariable("WEBSITE_SITE_NAME", null);
-        }
+        Environment.SetEnvironmentVariable("WEBSITE_SITE_NAME", "AzureAppService");
+        Environment.SetEnvironmentVariable("WEBSITE_INSTANCE_ID", "AzureInstance");
+        var resource = ResourceBuilder.CreateEmpty().AddDetector(new AppServiceResourceDetector()).Build();
+        Assert.NotNull(resource);
+        Assert.Contains(new KeyValuePair<string, object>(ResourceSemanticConventions.AttributeServiceName, "AzureAppService"), resource.Attributes);
+        Assert.Contains(new KeyValuePair<string, object>(ResourceSemanticConventions.AttributeServiceInstance, "AzureInstance"), resource.Attributes);
     }
 
     [Fact]
@@ -46,4 +41,10 @@ public void AppServiceResourceDetectorReturnsNullOutsideOfAppService()
         var resource = new AppServiceResourceDetector().Detect();
         Assert.Empty(resource.Attributes);
     }
+
+    public void Dispose()
+    {
+        Environment.SetEnvironmentVariable("WEBSITE_SITE_NAME", null);
+        Environment.SetEnvironmentVariable("WEBSITE_INSTANCE_ID", null);
+    }
 }