From a4959834d0362fe63fc7a288fc089df293bd2e21 Mon Sep 17 00:00:00 2001
From: Rajkumar Rangaraj <rajrang@microsoft.com>
Date: Fri, 27 Mar 2026 16:39:22 -0700
Subject: [PATCH 1/3] Add OpenTelemetry forwarder infrastructure

- Add OpenTelemetry.OutOfProcess.Forwarder.Configuration 0.1.0-beta.1 package version
- Add ENABLE_OTEL conditional compilation: when set, adds package reference and
  defines BUILDING_OTEL preprocessor symbol
- Set ENABLE_OTEL in generate-dev-sln.ps1 for dev builds
- Fix missing newline at end of generate-dev-sln.ps1
---
 Directory.Packages.props                       | 1 +
 generate-dev-sln.ps1                           | 1 +
 src/Tools/dotnet-monitor/dotnet-monitor.csproj | 8 ++++++++
 3 files changed, 10 insertions(+)

diff --git a/Directory.Packages.props b/Directory.Packages.props
index f37bd594e4c..9c25c8b1d13 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -26,6 +26,7 @@
     <PackageVersion Include="Newtonsoft.Json" Version="$(NewtonsoftJsonVersion)" />
     <PackageVersion Include="NJsonSchema" Version="$(NJsonSchemaVersion)" />
     <PackageVersion Include="NJsonSchema.NewtonsoftJson" Version="$(NJsonSchemaVersion)" />
+    <PackageVersion Include="OpenTelemetry.OutOfProcess.Forwarder.Configuration" Version="0.1.0-beta.1" />
     <PackageVersion Include="System.CommandLine" Version="$(SystemCommandLineVersion)" />
     <PackageVersion Include="System.Private.Uri" Version="$(SystemPrivateUriVersion)" />
     <PackageVersion Include="System.Text.Json" Version="$(SystemTextJsonVersion)" />
diff --git a/generate-dev-sln.ps1 b/generate-dev-sln.ps1
index fec6c0823db..1ca59051850 100644
--- a/generate-dev-sln.ps1
+++ b/generate-dev-sln.ps1
@@ -10,6 +10,7 @@ $ErrorActionPreference = 'Stop'
 
 $resolvedPath = Resolve-Path $DiagRepoRoot
 $env:DIAGNOSTICS_REPO_ROOT=$resolvedPath
+$env:ENABLE_OTEL="true"
 
 #Generates a solution that spans both the diagnostics and the dotnet-monitor repo.
 #This can be used to build both projects in VS.
diff --git a/src/Tools/dotnet-monitor/dotnet-monitor.csproj b/src/Tools/dotnet-monitor/dotnet-monitor.csproj
index 34993f9604f..a38477bb388 100644
--- a/src/Tools/dotnet-monitor/dotnet-monitor.csproj
+++ b/src/Tools/dotnet-monitor/dotnet-monitor.csproj
@@ -28,6 +28,10 @@
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" GeneratePathProperty="true" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(ENABLE_OTEL)' != ''">
+    <PackageReference Include="OpenTelemetry.OutOfProcess.Forwarder.Configuration" />
+  </ItemGroup>
+
   <ItemGroup Condition="'$(DIAGNOSTICS_REPO_ROOT)' == ''">
     <PackageReference Include="Microsoft.Diagnostics.Monitoring" />
   </ItemGroup>
@@ -36,6 +40,10 @@
     <ProjectReference Include="$(DIAGNOSTICS_REPO_ROOT)\src\Microsoft.Diagnostics.Monitoring\Microsoft.Diagnostics.Monitoring.csproj" />
   </ItemGroup>
 
+  <PropertyGroup Condition="'$(ENABLE_OTEL)' != ''">
+    <DefineConstants>$(DefineConstants);BUILDING_OTEL</DefineConstants>
+  </PropertyGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\..\Microsoft.Diagnostics.Monitoring.Options\Microsoft.Diagnostics.Monitoring.Options.csproj" />
     <ProjectReference Include="..\..\Microsoft.Diagnostics.Monitoring.WebApi\Microsoft.Diagnostics.Monitoring.WebApi.csproj" />

From d54b0b5ce87c82da54f8da2686fc3084ea740d04 Mon Sep 17 00:00:00 2001
From: Rajkumar Rangaraj <rajrang@microsoft.com>
Date: Fri, 3 Apr 2026 15:54:16 -0700
Subject: [PATCH 2/3] Make OpenTelemetry package reference and BUILDING_OTEL
 unconditional

Address review feedback: remove ENABLE_OTEL gating so the package
is always referenced and BUILDING_OTEL is always defined, avoiding
the need for two separate builds.
---
 generate-dev-sln.ps1                           | 1 -
 src/Tools/dotnet-monitor/dotnet-monitor.csproj | 7 ++-----
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/generate-dev-sln.ps1 b/generate-dev-sln.ps1
index 1ca59051850..fec6c0823db 100644
--- a/generate-dev-sln.ps1
+++ b/generate-dev-sln.ps1
@@ -10,7 +10,6 @@ $ErrorActionPreference = 'Stop'
 
 $resolvedPath = Resolve-Path $DiagRepoRoot
 $env:DIAGNOSTICS_REPO_ROOT=$resolvedPath
-$env:ENABLE_OTEL="true"
 
 #Generates a solution that spans both the diagnostics and the dotnet-monitor repo.
 #This can be used to build both projects in VS.
diff --git a/src/Tools/dotnet-monitor/dotnet-monitor.csproj b/src/Tools/dotnet-monitor/dotnet-monitor.csproj
index a38477bb388..48f04e6a89e 100644
--- a/src/Tools/dotnet-monitor/dotnet-monitor.csproj
+++ b/src/Tools/dotnet-monitor/dotnet-monitor.csproj
@@ -24,14 +24,11 @@
     <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" />
     <PackageReference Include="Microsoft.AspNetCore.Authentication.Negotiate" />
     <PackageReference Include="Microsoft.Identity.Web" />
+    <PackageReference Include="OpenTelemetry.OutOfProcess.Forwarder.Configuration" />
     <PackageReference Include="System.CommandLine" />
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" GeneratePathProperty="true" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(ENABLE_OTEL)' != ''">
-    <PackageReference Include="OpenTelemetry.OutOfProcess.Forwarder.Configuration" />
-  </ItemGroup>
-
   <ItemGroup Condition="'$(DIAGNOSTICS_REPO_ROOT)' == ''">
     <PackageReference Include="Microsoft.Diagnostics.Monitoring" />
   </ItemGroup>
@@ -40,7 +37,7 @@
     <ProjectReference Include="$(DIAGNOSTICS_REPO_ROOT)\src\Microsoft.Diagnostics.Monitoring\Microsoft.Diagnostics.Monitoring.csproj" />
   </ItemGroup>
 
-  <PropertyGroup Condition="'$(ENABLE_OTEL)' != ''">
+  <PropertyGroup>
     <DefineConstants>$(DefineConstants);BUILDING_OTEL</DefineConstants>
   </PropertyGroup>
 

From f52f7cd7b4ee5b454906eedc68f4829ea1f77038 Mon Sep 17 00:00:00 2001
From: Rajkumar Rangaraj <rajrang@microsoft.com>
Date: Fri, 3 Apr 2026 16:02:27 -0700
Subject: [PATCH 3/3] Remove BUILDING_OTEL define

---
 src/Tools/dotnet-monitor/dotnet-monitor.csproj | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/src/Tools/dotnet-monitor/dotnet-monitor.csproj b/src/Tools/dotnet-monitor/dotnet-monitor.csproj
index 48f04e6a89e..9d276e9522b 100644
--- a/src/Tools/dotnet-monitor/dotnet-monitor.csproj
+++ b/src/Tools/dotnet-monitor/dotnet-monitor.csproj
@@ -37,10 +37,6 @@
     <ProjectReference Include="$(DIAGNOSTICS_REPO_ROOT)\src\Microsoft.Diagnostics.Monitoring\Microsoft.Diagnostics.Monitoring.csproj" />
   </ItemGroup>
 
-  <PropertyGroup>
-    <DefineConstants>$(DefineConstants);BUILDING_OTEL</DefineConstants>
-  </PropertyGroup>
-
   <ItemGroup>
     <ProjectReference Include="..\..\Microsoft.Diagnostics.Monitoring.Options\Microsoft.Diagnostics.Monitoring.Options.csproj" />
     <ProjectReference Include="..\..\Microsoft.Diagnostics.Monitoring.WebApi\Microsoft.Diagnostics.Monitoring.WebApi.csproj" />