Add host.arch attribute to HostDetector and update tests

src/OpenTelemetry.Resources.Host/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+* Added support for the `host.arch` resource attribute in `HostDetector`, reporting the host architecture (e.g., `X64`, `Arm64`) using `System.Runtime.InteropServices.RuntimeInformation.ProcessArchitecture`.
+
 ## 1.12.0-beta.1
 
 Released 2025-May-06

src/OpenTelemetry.Resources.Host/HostDetector.cs

@@ -94,6 +94,14 @@ public Resource Detect()
             {
                 attributes.Add(new(HostSemanticConventions.AttributeHostId, machineId));
             }
+#if !NETFRAMEWORK
+            // Architecture is only supported in .NET 5+
+            var arch = RuntimeInformation.ProcessArchitecture.ToString();
+            if (arch != null && !string.IsNullOrEmpty(arch))
+            {
+                attributes.Add(new(HostSemanticConventions.AttributeHostArch, arch));
+            }
+#endif
 
             return new Resource(attributes);
         }

src/OpenTelemetry.Resources.Host/HostSemanticConventions.cs

@@ -7,4 +7,5 @@ internal static class HostSemanticConventions
 {
     public const string AttributeHostName = "host.name";
     public const string AttributeHostId = "host.id";
+    public const string AttributeHostArch = "host.arch";
 }

src/OpenTelemetry.Resources.Host/README.md

@@ -54,8 +54,11 @@
 The resource detectors will record the following metadata based on where
 your application is running:
 
-- **HostDetector**: `host.id` (when running on non-containerized systems), `host.name`.
+- **HostDetector**:
+  - `host.id` (when running on non-containerized systems)
+  - `host.name`
+  - `host.arch` (the host architecture, e.g., `X64`, `Arm64`)
 
 ## References
 
-- [OpenTelemetry Project](https://opentelemetry.io/)
+- [OpenTelemetry Project](https://opentelemetry.io/)

test/OpenTelemetry.Resources.Host.Tests/HostDetectorTests.cs

@@ -51,10 +51,18 @@
 
         var resourceAttributes = resource.Attributes.ToDictionary(x => x.Key, x => (string)x.Value);
 
+#if NET
+        Assert.Equal(3, resourceAttributes.Count);
+#else
         Assert.Equal(2, resourceAttributes.Count);
+#endif
 
         Assert.NotEmpty(resourceAttributes[HostSemanticConventions.AttributeHostName]);
         Assert.NotEmpty(resourceAttributes[HostSemanticConventions.AttributeHostId]);
+#if NET
+        Assert.NotEmpty(resourceAttributes["host.arch"]);
+        Assert.Equal(System.Runtime.InteropServices.RuntimeInformation.ProcessArchitecture.ToString(), resourceAttributes["host.arch"]);
+#endif
     }
 
 #if NET