ci(build): target .NET 10 Alpine with low-memory tuning

.github/workflows/ci.yaml

@@ -25,7 +25,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-dotnet@v3
         with:
-          dotnet-version: '9' # SDK Version to use.
+          dotnet-version: '10' # SDK Version to use.
           dotnet-quality: 'ga'
           cache: true
           cache-dependency-path: '**/packages.lock.json'
@@ -42,6 +42,6 @@ jobs:
       - name: Publish container
         run: |
           dotnet publish \
-          --configuration Release --os linux --arch x64 \
+          --configuration Release --os linux-musl --arch x64 \
           /t:PublishContainer -p ContainerRegistry=ghcr.io \
           -p ContainerRepository=${{ github.repository }} -p:ContainerImageTags='"${{ steps.metadata.outputs.APP_VERSION }};latest"'

CaddyManager/CaddyManager.csproj

@@ -10,8 +10,23 @@
         <RestorePackagesWithLockFile>true</RestorePackagesWithLockFile>
         <!-- To avoid error on lock file not found -->
         <DisableImplicitNuGetFallbackFolder>true</DisableImplicitNuGetFallbackFolder>
+        <!--
+            Low-traffic single-user admin UI: trade GC throughput for a much smaller heap.
+            Server GC (the Web SDK default) reserves one heap per CPU core.
+        -->
+        <ServerGarbageCollection>false</ServerGarbageCollection>
+        <ConcurrentGarbageCollection>false</ConcurrentGarbageCollection>
+        <TieredPGO>false</TieredPGO>
+        <!-- No localized content, so skip loading ICU entirely (alpine ships no ICU anyway) -->
+        <InvariantGlobalization>true</InvariantGlobalization>
+        <ContainerBaseImage>mcr.microsoft.com/dotnet/aspnet:10.0-alpine</ContainerBaseImage>
     </PropertyGroup>
 
+    <ItemGroup>
+        <!-- No MSBuild property exists for this one; lands in runtimeconfig.json for both build paths -->
+        <RuntimeHostConfigurationOption Include="System.GC.ConserveMemory" Value="9" />
+    </ItemGroup>
+
     <ItemGroup>
       <Content Include="..\.dockerignore">
         <Link>.dockerignore</Link>

CaddyManager/Dockerfile

@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/dotnet/aspnet:10.0 AS base
+FROM mcr.microsoft.com/dotnet/aspnet:10.0-alpine AS base
 USER $APP_UID
 WORKDIR /app
 EXPOSE 8080

CaddyManager/Program.cs

@@ -1,4 +1,5 @@
 using CaddyManager.Components;
+using Microsoft.AspNetCore.Components.Server;
 using MudBlazor.Services;
 using NetCore.AutoRegisterDi;
 
@@ -6,7 +7,6 @@ var builder = WebApplication.CreateBuilder(args);
 
 // Add services to the container.
 builder.Services
-    .AddMudServices()
     .AddRazorComponents()
     .AddInteractiveServerComponents();
 
@@ -15,7 +15,20 @@ builder.Services.RegisterAssemblyPublicNonGenericClasses(System.Reflection.Assem
     .Where(t => t.Name.EndsWith("Service"))
     .AsPublicImplementedInterfaces();
 
-builder.Services.AddSignalR(e => { e.MaximumReceiveMessageSize = 102400000; });
+builder.Services.AddSignalR(e =>
+{
+    // Caddyfiles are kilobytes; this is generous headroom for Monaco editor round-trips
+    e.MaximumReceiveMessageSize = 512 * 1024;
+    e.StreamBufferCapacity = 5;
+});
+
+// Keep as little per-circuit state resident as practical for a single-user admin UI
+builder.Services.Configure<CircuitOptions>(o =>
+{
+    o.DisconnectedCircuitRetentionPeriod = TimeSpan.FromMinutes(1);
+    o.DisconnectedCircuitMaxRetained = 5;
+    o.MaxBufferedUnacknowledgedRenderBatches = 3;
+});
 
 builder.Services.AddMudServices(config =>
 {

CaddyManager/packages.lock.json

@@ -524,6 +524,7 @@
           "NetCore.AutoRegisterDi": "[2.2.1, )"
         }
       }
-    }
+    },
+    "net10.0/linux-musl-x64": {}
   }
 }

README.md

@@ -163,6 +163,10 @@ services:
       DockerService__CaddyConfigPathInContainer: "/etc/caddy/Caddyfile"
     # To have the access to the caddy config file
     user: "1000:1000"
+    # The .NET GC sizes its heap against the cgroup limit, so this both caps the worst
+    # case and makes the runtime self-tune downward. Raise it if you run many configs.
+    mem_limit: 256m
+    memswap_limit: 256m
     ports:
       - "8080:8080"
     volumes:

compose.yaml

@@ -19,6 +19,10 @@
       CaddyService__ConfigDir: "/config"
       DockerService__CaddyContainerName: "caddy"
     user: "1000:1000"
+    # The .NET GC sizes its heap against the cgroup limit, so this both caps the
+    # worst case and makes the runtime self-tune downward.
+    mem_limit: 256m
+    memswap_limit: 256m
     ports:
       - "8080:8080"
     volumes: