d daedalus

.NET / C#

Building a .NET / C# App

daedalus supports .NET apps. It detects a .NET project by the presence of a *.csproj or *.sln file.

Detection

File Strategy
*.csproj Reads <OutputType> (Exe or Library)
publish/ dir Uses pre-published output (self-contained or framework-dependent)
bin/Release/net*/publish/ Standard publish location

Prerequisites

  • .NET SDK installed (dotnet on PATH)
  • For published apps: dotnet publish before building

Build

# Published app (recommended)
cd my-dotnet-app
dotnet publish -c Release
daedalus build . -o my-app.de

# Dev project (uses dotnet run, slower startup)
daedalus build . -o my-app.de

The builder:

  1. detects the dotnet runtime and parses the .csproj for OutputType;
  2. checks for a publish/ directory (pre-built output);
  3. embeds the dotnet interpreter and its shared libraries;
  4. packages the published DLLs into the app layer;
  5. compresses and assembles the .de.

Published vs dev mode

Published (recommended)

If publish/ or bin/Release/net*/publish/ exists, the launcher runs:

/opt/dotnet/dotnet /app/publish/MyApp.dll

This is faster and produces a smaller binary (no SDK needed at runtime).

Dev mode (fallback)

If no publish directory exists, the launcher runs:

/opt/dotnet/dotnet run --project /app/MyApp.csproj

This requires the SDK in the runtime layer (larger binary, slower startup).

Self-contained vs framework-dependent

  • Self-contained (dotnet publish --self-contained): includes the .NET runtime in the output. Larger binary but no runtime dependency on the target.
  • Framework-dependent (dotnet publish): requires .NET runtime on the target. Smaller binary but the runtime must match.

daedalus works with both. Self-contained is recommended for maximum portability.

Environment variables

DOTNET_ENVIRONMENT=Production ./my-app.de
ASPNETCORE_URLS="http://0.0.0.0:9000" ./my-app.de

Known limitations

  • Only .NET 8+ is tested. Earlier versions may work but are not guaranteed.
  • .NET class libraries (<OutputType>Library</OutputType>) cannot be packaged directly — they need an executable entry point.
  • Blazor Server apps work. Blazor WebAssembly does not (requires browser).
  • F# projects (*.fsproj) are not yet supported but should work once detected.
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