Upgrade to .NET 8 + latest LTS of IoT SDKs (#7262)

In preparation for v1.5, this change updates our C# code to .NET 8.0. It also updates our dependency on the IoT SDKs to the latest LTS versions (Microsoft.Azure.Devices.Client 1.36.10, Microsoft.Azure.Devices 1.31.6). I had to upgrade our dependency on Azure.Storage.Blobs because the device SDK upgraded theirs. This required that I upgrade the code in Edge Agent and some test modules to use newer storage blob libraries that aren't deprecated. I did local testing of the Edge Agent code to ensure that the new calls work as expected. I updated the buildBranch.sh and runTests.sh scripts. buildBranch.sh was building two different ways: (1) it was doing a standard build of all .NET components from the repo root (`dotnet build -c Release`), and (2) it was publishing each "app" in a manner suitable for including in Docker images. I simplified it to just focus on the second scenario. For the first, I updated dotnet.yaml to call `dotnet test` directly. I simplified runTests.sh to use `dotnet test` instead of `dotnet vstest` (which is being deprecated) because `dotnet test` now supports running pre-built binaries instead of always building the binaries itself. Note that `dotnet test` apparently doesn't support some of the parallelization features that vstest did, but the time difference is minimal and the script logic is vastly simplified. I updated EdgeHubTriggerCsharp.csproj to specify its own TargetFramework property, rather than including netcoreappVersion.props, because it has dependedencies that don't yet support .NET 8. I successfully ran the CI Build pipeline with these changes. To test, I ran the end-to-end tests, nested end-to-end tests, connectivity tests, and ISA-95 smoke tests against the new bits. ## Azure IoT Edge PR checklist:
Azure · Apr 12, 2024 · 7508ffc · 7508ffc
1 parent 54e46fd
commit 7508ffc
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diff --git a/.gitignore b/.gitignore
@@ -332,3 +332,6 @@ parts/
 stage/
 prime/
 *.snap
+
+# used by the C# Dev Kit (VS Code extension)
+.mono/
diff --git a/builds/checkin/dotnet.yaml b/builds/checkin/dotnet.yaml
@@ -37,12 +37,12 @@ jobs:
   steps:
   - script: scripts/linux/installPrereqs.sh
     displayName: Install Prerequisites
-  - script: scripts/linux/buildBranch.sh -c '$(configuration)'
-    displayName: Build
-  - script: scripts/linux/runTests.sh '--filter Category=Unit&Category!=GetLogsTests'
-    displayName: Test
-  - script: scripts/linux/runTests.sh '--filter Category=GetLogsTests'
-    displayName: Run GetLogsTests Tests
+  - script: |
+      dotnet test \
+        --configuration $(configuration) \
+        --filter 'Category=Unit' \
+        --logger trx \
+    displayName: Build and run unit tests
   - task: PublishTestResults@2
     displayName: Publish Test Results
     inputs:
@@ -69,19 +69,10 @@ jobs:
       dotnet test \
         --logger trx \
         --results-directory '$(Agent.TempDirectory)' \
-        --filter 'Category=Unit&Category!=GetLogsTests' \
+        --filter 'Category=Unit' \
         --collect 'xplat code coverage' \
         --settings CodeCoverage.runsettings
     displayName: Run unit tests with code coverage
-  - script: |
-      dotnet test 'edge-agent/test/Microsoft.Azure.Devices.Edge.Agent.Core.Test' \
-        --logger trx \
-        --results-directory '$(Agent.TempDirectory)' \
-        --filter 'Category=GetLogsTests' \
-        --collect 'xplat code coverage' \
-        --settings CodeCoverage.runsettings
-    displayName: Run GetLogsTests unit tests with code coverage
-    condition: succeededOrFailed()
   - script: |
       dotnet new tool-manifest
       dotnet tool install dotnet-reportgenerator-globaltool

diff --git a/builds/ci/dotnet.yaml b/builds/ci/dotnet.yaml
@@ -49,7 +49,7 @@ jobs:
           CERT_VALUE: $(IotHubMqttHeadCert)
       - script: scripts/linux/buildBranch.sh -c $(Build.Configuration) --no-rocksdb-bin --skip-quickstart
         displayName: Build
-      - script: sudo -E bash -c './scripts/linux/runTests.sh "--filter $(test.filter)&Category!=Kubernetes" $(Build.Configuration)'
+      - script: sudo -E bash -c './scripts/linux/runTests.sh "$(test.filter)" "$(Build.Configuration)"'
         displayName: Integration Tests
         env:
           DummySecret1: $(DummySecret1)
@@ -59,28 +59,6 @@ jobs:
           IotDevice3ConnStr2: $(IotDevice3ConnStr2)
           IotHubConnStr2: $(IotHubConnStr2)
           IotHubMqttHeadCert: $(IotHubMqttHeadCert)
-#      - script: |
-#          # download kind binary and make it executable
-#          curl -Lo ./kind https://github.com/kubernetes-sigs/kind/releases/download/v0.5.1/kind-$(uname)-amd64
-#          chmod +x ./kind
-#          # move it to $AGENT_TOOLSDIRECTORY\kind
-#          mkdir $AGENT_TOOLSDIRECTORY/kind
-#          mv ./kind $AGENT_TOOLSDIRECTORY/kind/kind
-#          # make kind to be available for integration tests
-#          echo "##vso[task.setvariable variable=PATH;]$AGENT_TOOLSDIRECTORY/kind:$PATH"
-#        displayName: Install Kubernetes cluster manager (kind)
-#        condition: succeededOrFailed()
-#      - script: |
-#          kind create cluster --name "edgy" --wait 5m
-#          KUBECONFIG=$(kind get kubeconfig-path --name "edgy")
-#          echo "##vso[task.setvariable variable=KUBECONFIG;]$KUBECONFIG"
-#          echo "##vso[task.setvariable variable=USE_EXISTING_KUBERNETES_CLUSTER;]true"
-#        displayName: Create Kubernetes cluster (edgy)
-#        condition: succeededOrFailed()
-#      - script: |
-#          sudo -E bash -c './scripts/linux/runTests.sh "--filter $(test.filter)&Category=Kubernetes" $(Build.Configuration)'
-#        displayName: Kubernetes Integration Tests
-#        condition: succeededOrFailed()
       - task: PublishTestResults@2
         displayName: Publish test results
         inputs:

diff --git a/builds/e2e/templates/e2e-setup.yaml b/builds/e2e/templates/e2e-setup.yaml
@@ -113,7 +113,7 @@ steps:
       $testDir = '$(Build.SourcesDirectory)/test/Microsoft.Azure.Devices.Edge.Test'
       dotnet build $testDir
   
-      $binDir = Convert-Path "$testDir/bin/Debug/net6.0"
+      $binDir = Convert-Path "$testDir/bin/Debug/net8.0"
       Write-Output "##vso[task.setvariable variable=binDir]$binDir"
     env:
       http_proxy: $(Agent.ProxyUrl)

diff --git a/doc/devguide.md b/doc/devguide.md
@@ -59,7 +59,7 @@ scripts/linux/downloadAndInstallCert.sh -v <VaultName> -c <CertName>
 Then run the tests either with Test Explorer in Visual Studio IDE, or with:
 
 ```sh
-scripts/linux/runTests.sh "--filter Category=Integration"
+scripts/linux/runTests.sh "Category=Integration"
 ```
 
 The syntax of the "filter" argument is described [here](https://docs.microsoft.com/dotnet/core/tools/dotnet-test#filter-option-details). All IoT Edge tests are categorized as one of `Unit`, `Integration`, or `Bvt`.

diff --git a/edge-agent/docker/linux/Dockerfile b/edge-agent/docker/linux/Dockerfile
@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1.4
 
-FROM mcr.microsoft.com/dotnet/aspnet:6.0-alpine
+FROM mcr.microsoft.com/dotnet/aspnet:8.0-alpine
 
 ARG EXE_DIR=.
 ARG TARGETPLATFORM

diff --git a/...zure.Devices.Edge.Agent.Diagnostics/Microsoft.Azure.Devices.Edge.Agent.Diagnostics.csproj b/...zure.Devices.Edge.Agent.Diagnostics/Microsoft.Azure.Devices.Edge.Agent.Diagnostics.csproj
@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Azure.Devices.Client" Version="1.36.8" />
+    <PackageReference Include="Microsoft.Azure.Devices.Client" Version="1.36.10" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="5.0.0" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.2" />
     <PackageReference Include="System.Linq.Async" Version="4.1.1" />

diff --git a/edge-agent/src/Microsoft.Azure.Devices.Edge.Agent.IoTHub/AzureAppendBlob.cs b/edge-agent/src/Microsoft.Azure.Devices.Edge.Agent.IoTHub/AzureAppendBlob.cs
@@ -2,21 +2,23 @@
 namespace Microsoft.Azure.Devices.Edge.Agent.IoTHub
 {
     using System;
+    using System.IO;
     using System.Threading.Tasks;
+    using global::Azure.Storage.Blobs.Specialized;
     using Microsoft.Azure.Devices.Edge.Util;
-    using Microsoft.WindowsAzure.Storage.Blob;
 
     class AzureAppendBlob : IAzureAppendBlob
     {
-        readonly CloudAppendBlob appendBlob;
+        readonly AppendBlobClient appendBlob;
 
-        public AzureAppendBlob(CloudAppendBlob appendBlob)
+        public AzureAppendBlob(AppendBlobClient appendBlob)
         {
             this.appendBlob = Preconditions.CheckNotNull(appendBlob, nameof(appendBlob));
         }
 
         public string Name => this.appendBlob.Name;
 
-        public Task AppendByteArray(ArraySegment<byte> bytes) => this.appendBlob.AppendFromByteArrayAsync(bytes.Array, bytes.Offset, bytes.Count);
+        public Task AppendByteArray(ArraySegment<byte> bytes) =>
+            this.appendBlob.AppendBlockAsync(new MemoryStream(bytes.Array, bytes.Offset, bytes.Count));
     }
 }
diff --git a/...icrosoft.Azure.Devices.Edge.Agent.IoTHub/Microsoft.Azure.Devices.Edge.Agent.IoTHub.csproj b/...icrosoft.Azure.Devices.Edge.Agent.IoTHub/Microsoft.Azure.Devices.Edge.Agent.IoTHub.csproj
@@ -9,8 +9,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Azure.Devices" Version="1.31.5" />
-    <PackageReference Include="Microsoft.Azure.Devices.Client" Version="1.36.8" />
+    <PackageReference Include="Microsoft.Azure.Devices" Version="1.31.6" />
+    <PackageReference Include="Microsoft.Azure.Devices.Client" Version="1.36.10" />
+    <PackageReference Include="Azure.Storage.Blobs" Version="12.19.1" />
   </ItemGroup>
 
   <ItemGroup>

diff --git a/edge-agent/src/Microsoft.Azure.Devices.Edge.Agent.IoTHub/blob/AzureBlob.cs b/edge-agent/src/Microsoft.Azure.Devices.Edge.Agent.IoTHub/blob/AzureBlob.cs
@@ -3,22 +3,29 @@ namespace Microsoft.Azure.Devices.Edge.Agent.IoTHub.Blob
 {
     using System.IO;
     using System.Threading.Tasks;
+    using global::Azure.Storage.Blobs.Models;
+    using global::Azure.Storage.Blobs.Specialized;
     using Microsoft.Azure.Devices.Edge.Util;
-    using Microsoft.WindowsAzure.Storage.Blob;
 
     class AzureBlob : IAzureBlob
     {
-        readonly CloudBlockBlob blockBlob;
+        readonly BlockBlobClient blockBlob;
+        readonly BlobHttpHeaders headers;
 
-        public AzureBlob(CloudBlockBlob blockBlob)
+        public AzureBlob(BlockBlobClient blockBlob, BlobHttpHeaders headers)
         {
             this.blockBlob = Preconditions.CheckNotNull(blockBlob, nameof(blockBlob));
+            this.headers = Preconditions.CheckNotNull(headers, nameof(headers));
         }
 
         public string Name => this.blockBlob.Name;
 
-        public Task UploadFromByteArrayAsync(byte[] bytes) => this.blockBlob.UploadFromByteArrayAsync(bytes, 0, bytes.Length);
+        public Task UploadFromByteArrayAsync(byte[] bytes)
+        {
+            var options = new BlobUploadOptions { HttpHeaders = this.headers };
+            return this.blockBlob.UploadAsync(new MemoryStream(bytes), options);
+        }
 
-        public Task UploadFromStreamAsync(Stream source) => this.blockBlob.UploadFromStreamAsync(source);
+        public Task UploadFromStreamAsync(Stream source) => this.blockBlob.UploadAsync(source);
     }
 }
diff --git a/edge-agent/src/Microsoft.Azure.Devices.Edge.Agent.IoTHub/blob/AzureBlobRequestsUploader.cs b/edge-agent/src/Microsoft.Azure.Devices.Edge.Agent.IoTHub/blob/AzureBlobRequestsUploader.cs
@@ -5,12 +5,12 @@ namespace Microsoft.Azure.Devices.Edge.Agent.IoTHub.Blob
     using System.Globalization;
     using System.IO;
     using System.Threading.Tasks;
+    using global::Azure.Storage.Blobs;
     using Microsoft.Azure.Devices.Edge.Agent.Core;
     using Microsoft.Azure.Devices.Edge.Agent.Core.Logs;
     using Microsoft.Azure.Devices.Edge.Util;
     using Microsoft.Azure.Devices.Edge.Util.TransientFaultHandling;
     using Microsoft.Extensions.Logging;
-    using Microsoft.WindowsAzure.Storage.Blob;
 
     public class AzureBlobRequestsUploader : IRequestsUploader
     {
@@ -47,7 +47,7 @@ public async Task UploadLogs(string uri, string id, byte[] payload, LogsContentE
             {
                 var containerUri = new Uri(uri);
                 string blobName = this.GetBlobName(id, GetLogsExtension(logsContentEncoding, logsContentType));
-                var container = new CloudBlobContainer(containerUri);
+                var container = new BlobContainerClient(containerUri);
                 Events.Uploading(blobName, container.Name);
 
                 await ExecuteWithRetry(
@@ -74,7 +74,7 @@ public async Task<Func<ArraySegment<byte>, Task>> GetLogsUploaderCallback(string
 
             var containerUri = new Uri(uri);
             string blobName = this.GetBlobName(id, GetLogsExtension(logsContentEncoding, logsContentType));
-            var container = new CloudBlobContainer(containerUri);
+            var container = new BlobContainerClient(containerUri);
             Events.Uploading(blobName, container.Name);
             IAzureAppendBlob blob = await this.azureBlobUploader.GetAppendBlob(containerUri, blobName, GetContentType(logsContentType), GetContentEncoding(logsContentEncoding));
             return blob.AppendByteArray;
@@ -89,7 +89,7 @@ public async Task UploadSupportBundle(string uri, Stream source)
             {
                 var containerUri = new Uri(uri);
                 string blobName = this.GetBlobName("support-bundle", "zip");
-                var container = new CloudBlobContainer(containerUri);
+                var container = new BlobContainerClient(containerUri);
                 Events.Uploading(blobName, container.Name);
                 await ExecuteWithRetry(
                     () =>

diff --git a/edge-agent/src/Microsoft.Azure.Devices.Edge.Agent.IoTHub/blob/AzureBlobUploader.cs b/edge-agent/src/Microsoft.Azure.Devices.Edge.Agent.IoTHub/blob/AzureBlobUploader.cs
@@ -3,28 +3,33 @@ namespace Microsoft.Azure.Devices.Edge.Agent.IoTHub.Blob
 {
     using System;
     using System.Threading.Tasks;
+    using global::Azure.Storage.Blobs;
+    using global::Azure.Storage.Blobs.Models;
+    using global::Azure.Storage.Blobs.Specialized;
     using Microsoft.Azure.Devices.Edge.Util;
-    using Microsoft.WindowsAzure.Storage.Blob;
 
     class AzureBlobUploader : IAzureBlobUploader
     {
         public IAzureBlob GetBlob(Uri containerUri, string blobName, Option<string> contentType, Option<string> contentEncoding)
         {
-            var container = new CloudBlobContainer(Preconditions.CheckNotNull(containerUri, nameof(containerUri)));
-            CloudBlockBlob blob = container.GetBlockBlobReference(Preconditions.CheckNonWhiteSpace(blobName, nameof(blobName)));
-            contentType.ForEach(c => blob.Properties.ContentType = c);
-            contentEncoding.ForEach(c => blob.Properties.ContentEncoding = c);
-            var azureBlob = new AzureBlob(blob);
+            var container = new BlobContainerClient(Preconditions.CheckNotNull(containerUri, nameof(containerUri)));
+            BlockBlobClient blob = container.GetBlockBlobClient(Preconditions.CheckNonWhiteSpace(blobName, nameof(blobName)));
+            var headers = new BlobHttpHeaders();
+            contentType.ForEach(c => headers.ContentType = c);
+            contentEncoding.ForEach(c => headers.ContentEncoding = c);
+            var azureBlob = new AzureBlob(blob, headers);
             return azureBlob;
         }
 
         public async Task<IAzureAppendBlob> GetAppendBlob(Uri containerUri, string blobName, Option<string> contentType, Option<string> contentEncoding)
         {
-            var container = new CloudBlobContainer(Preconditions.CheckNotNull(containerUri, nameof(containerUri)));
-            CloudAppendBlob blob = container.GetAppendBlobReference(Preconditions.CheckNonWhiteSpace(blobName, nameof(blobName)));
-            contentType.ForEach(c => blob.Properties.ContentType = c);
-            contentEncoding.ForEach(c => blob.Properties.ContentEncoding = c);
-            await blob.CreateOrReplaceAsync();
+            var container = new BlobContainerClient(Preconditions.CheckNotNull(containerUri, nameof(containerUri)));
+            AppendBlobClient blob = container.GetAppendBlobClient(Preconditions.CheckNonWhiteSpace(blobName, nameof(blobName)));
+            var headers = new BlobHttpHeaders();
+            contentType.ForEach(c => headers.ContentType = c);
+            contentEncoding.ForEach(c => headers.ContentEncoding = c);
+            var options = new AppendBlobCreateOptions { HttpHeaders = headers };
+            await blob.CreateAsync(options);
             var azureBlob = new AzureAppendBlob(blob);
             return azureBlob;
         }

diff --git a/...re/src/Microsoft.Azure.Devices.Edge.Hub.Amqp/Microsoft.Azure.Devices.Edge.Hub.Amqp.csproj b/...re/src/Microsoft.Azure.Devices.Edge.Hub.Amqp/Microsoft.Azure.Devices.Edge.Hub.Amqp.csproj
@@ -9,7 +9,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Azure.Amqp" Version="2.5.12" />
-    <PackageReference Include="Microsoft.Azure.Devices" Version="1.31.5" />
+    <PackageReference Include="Microsoft.Azure.Devices" Version="1.31.6" />
   </ItemGroup>
 
   <ItemGroup>

diff --git a/...soft.Azure.Devices.Edge.Hub.CloudProxy/Microsoft.Azure.Devices.Edge.Hub.CloudProxy.csproj b/...soft.Azure.Devices.Edge.Hub.CloudProxy/Microsoft.Azure.Devices.Edge.Hub.CloudProxy.csproj
@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Azure.Devices" Version="1.31.5" />
+    <PackageReference Include="Microsoft.Azure.Devices" Version="1.31.6" />
     <PackageReference Include="Stateless" Version="4.0.0" />
   </ItemGroup>
 

diff --git a/...re/src/Microsoft.Azure.Devices.Edge.Hub.Core/Microsoft.Azure.Devices.Edge.Hub.Core.csproj b/...re/src/Microsoft.Azure.Devices.Edge.Hub.Core/Microsoft.Azure.Devices.Edge.Hub.Core.csproj
@@ -18,21 +18,8 @@
   <ItemGroup>
     <PackageReference Include="App.Metrics" Version="3.0.0" />
     <PackageReference Include="JetBrains.Annotations" Version="2018.3.0" />
-    <PackageReference Include="Microsoft.Azure.Devices.Client" Version="1.36.8" />
+    <PackageReference Include="Microsoft.Azure.Devices.Client" Version="1.36.10" />
     <PackageReference Include="System.ValueTuple" Version="4.5.0" />
-    <!--
-      We have a transitive dependency on Dotnetty via Microsoft.Azure.Devices.Client. Use
-      explicit references here to override the version and fix a known OOM bug. See
-      https://github.com/Azure/DotNetty/pull/583. If Microsoft.Azure.Devices.Client updates
-      its dependency, we can remove the Dotnetty references.
-    -->
-    <PackageReference Include="DotNetty.Buffers" Version="0.7.5" />
-    <PackageReference Include="DotNetty.Codecs" Version="0.7.5" />
-    <PackageReference Include="DotNetty.Codecs.Mqtt" Version="0.7.5" />
-    <PackageReference Include="DotNetty.Common" Version="0.7.5" />
-    <PackageReference Include="DotNetty.Handlers" Version="0.7.5" />
-    <PackageReference Include="DotNetty.Transport" Version="0.7.5" />
-
   </ItemGroup>
 
   <ItemGroup>

diff --git a/...re/src/Microsoft.Azure.Devices.Edge.Hub.Http/Microsoft.Azure.Devices.Edge.Hub.Http.csproj b/...re/src/Microsoft.Azure.Devices.Edge.Hub.Http/Microsoft.Azure.Devices.Edge.Hub.Http.csproj
@@ -13,7 +13,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Azure.Devices" Version="1.31.5" />
+    <PackageReference Include="Microsoft.Azure.Devices" Version="1.31.6" />
   </ItemGroup>
 
   <ItemGroup>

diff --git a/edge-hub/core/src/Microsoft.Azure.Devices.Edge.Hub.Http/controllers/RegistryController.cs b/edge-hub/core/src/Microsoft.Azure.Devices.Edge.Hub.Http/controllers/RegistryController.cs
@@ -536,7 +536,7 @@ async Task SendResponseAsync(HttpStatusCode status, Dictionary<string, string> h
 
             foreach (var header in headers)
             {
-                this.Response.Headers.Add(header.Key, header.Value);
+                this.Response.Headers.Append(header.Key, header.Value);
             }
 
             if (!string.IsNullOrEmpty(jsonContent))

diff --git a/...re/src/Microsoft.Azure.Devices.Edge.Hub.Mqtt/Microsoft.Azure.Devices.Edge.Hub.Mqtt.csproj b/...re/src/Microsoft.Azure.Devices.Edge.Hub.Mqtt/Microsoft.Azure.Devices.Edge.Hub.Mqtt.csproj
@@ -11,19 +11,6 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="5.0.0" />
     <PackageReference Include="Microsoft.Azure.Devices.ProtocolGateway.Core" Version="2.0.1" />
-    <!--
-      We have a transitive dependency on Dotnetty via Microsoft.Azure.Devices.ProtocolGateway.Core.
-      Use explicit references here to override the version and fix a known OOM bug. See
-      https://github.com/Azure/DotNetty/pull/583. If ProtocolGateway updates its dependency,
-      we can remove the Dotnetty references.
-    -->
-    <PackageReference Include="DotNetty.Buffers" Version="0.7.5" />
-    <PackageReference Include="DotNetty.Codecs" Version="0.7.5" />
-    <PackageReference Include="DotNetty.Codecs.Mqtt" Version="0.7.5" />
-    <PackageReference Include="DotNetty.Common" Version="0.7.5" />
-    <PackageReference Include="DotNetty.Handlers" Version="0.7.5" />
-    <PackageReference Include="DotNetty.Transport" Version="0.7.5" />
-
   </ItemGroup>
 
   <ItemGroup>

diff --git a/edge-hub/core/src/Microsoft.Azure.Devices.Edge.Hub.Service/Startup.cs b/edge-hub/core/src/Microsoft.Azure.Devices.Edge.Hub.Service/Startup.cs
@@ -2,11 +2,13 @@
 namespace Microsoft.Azure.Devices.Edge.Hub.Service
 {
     using System;
+    using System.Linq;
     using System.Threading.Tasks;
     using Autofac;
     using Autofac.Extensions.DependencyInjection;
     using Microsoft.AspNetCore.Builder;
     using Microsoft.AspNetCore.Hosting;
+    using Microsoft.AspNetCore.Http;
     using Microsoft.AspNetCore.Mvc;
     using Microsoft.Azure.Devices.Edge.Hub.Core;
     using Microsoft.Azure.Devices.Edge.Hub.Http;
@@ -86,7 +88,7 @@ public void Configure(IApplicationBuilder app)
                 async (context, next) =>
                 {
                     // Response header is added to prevent MIME type sniffing
-                    context.Response.Headers.Add("X-Content-Type-Options", "nosniff");
+                    context.Response.Headers.Append("X-Content-Type-Options", "nosniff");
                     await next();
                 });
-Original file line number
+Diff line change
@@ Expand Up / @@ -332,3 +332,6 @@ parts/ @@
     stage/
     prime/
     *.snap
+    # used by the C# Dev Kit (VS Code extension)
+    .mono/