Update dotnet example (#54)

Author: brancz

dotnet/Dockerfile

@@ -1,12 +1,12 @@
-FROM mcr.microsoft.com/dotnet/runtime:7.0 AS base
+FROM mcr.microsoft.com/dotnet/runtime:8.0 AS base
 WORKDIR /app
 
 # Creates a non-root user with an explicit UID and adds permission to access the /app folder
 # For more info, please refer to https://aka.ms/vscode-docker-dotnet-configure-containers
 RUN adduser -u 5678 --disabled-password --gecos "" appuser && chown -R appuser /app
 USER appuser
 
-FROM mcr.microsoft.com/dotnet/sdk:7.0 AS build
+FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
 WORKDIR /src
 COPY ["demo.csproj", "./"]
 RUN dotnet restore "demo.csproj"
@@ -18,7 +18,6 @@ FROM build AS publish
 RUN dotnet publish "demo.csproj" -c Release -o /app/publish
 
 FROM base AS final
-ENV DOTNET_PerfMapEnabled=1
 WORKDIR /app
 COPY --from=publish /app/publish .
 ENTRYPOINT ["dotnet", "demo.dll"]

dotnet/Program.cs

@@ -4,9 +4,9 @@ namespace Demo
 {
   class Program
   {
-    static int Fibonacci(int n)
+    static long Fibonacci(int n)
     {
-      int a = 0, b = 1, tmp;
+      long a = 0, b = 1, tmp;
 
       for (int i = 0; i < n; i++)
       {
@@ -22,7 +22,7 @@ static void Main(string[] args)
     {
       while (true)
       {
-        Console.WriteLine(Fibonacci(42));
+        Console.WriteLine(Fibonacci(1000000000));
       }
     }
   }

dotnet/README.md

@@ -1,3 +1,7 @@
 # .NET
 
-See https://learn.microsoft.com/en-us/dotnet/core/runtime-config/debugging-profiling#export-perf-maps
+Version 7 and greater are supported. Version 8 introduced some things that make tracking functions a bit more difficult, but should largely still work.
+
+Known issues:
+- Very large functions can fail to be symbolized. This will be fixed with: https://github.com/dotnet/runtime/pull/108939
+- The runtime can incorrectly track inlining and line numbers. This is an issue with exception backtraces as well. https://dotnetdocs.ir/Post/47/wrong-exception-line-number-in-stack-trace-in-release-mode

dotnet/demo.csproj

@@ -1,10 +1,10 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-  <PropertyGroup>
-    <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
-    <Nullable>enable</Nullable>
-  </PropertyGroup>
-
-</Project>
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

dotnet/deployment.yaml

@@ -4,9 +4,8 @@ metadata:
   labels:
     app.kubernetes.io/name: demo-dotnet
   name: dotnet
-  namespace: parca
 spec:
-  replicas: 3
+  replicas: 1
   selector:
     matchLabels:
       app.kubernetes.io/name: demo-dotnet
@@ -16,7 +15,8 @@ spec:
         app.kubernetes.io/name: demo-dotnet
     spec:
       containers:
-      - image: parca-demo:dotnet
+      - image: quay.io/brancz/parca-demo-dotnet:latest
+        imagePullPolicy: Always
         name: dotnet
         resources:
           limits: