RDLC reports on Linux and in Docker

ReportViewer renders RDLC on Windows, under .NET Framework. The community port to modern .NET runs elsewhere, but its own README lists what breaks off Windows: fonts are measured with a Windows-only component, and images fail on other platforms from .NET 7, because System.Drawing is Windows-only (see the sources). On Linux that means copying Windows fonts into the image, working around the images, and living with the differences.

Tagua has none of those dependencies: it is managed .NET code, with no System.Drawing and no libgdiplus, and it does not look for fonts installed on the machine. A report renders the same on Windows, Linux and macOS, because everything it needs travels with the template.

Convert the reports

dotnet tool install --global Tagua.Cli
tagua import Reports

Each .rdlc becomes a .report.yaml template, embedded images are written next to it, and tagua-import-summary.md lists what, if anything, needs a look. Render them from your application as the ASP.NET Core guide shows.

Fonts travel with the templates

PDF has three font families built in, and Tagua draws Arial, Times New Roman and Courier New with them: reports that use only those need no font files at all. For any other font, tagua import lists it, and you declare its files in the template, next to it in your project:

fonts:
  Calibri:
    regular: fonts/Carlito-Regular.ttf
    bold: fonts/Carlito-Bold.ttf

Carlito, Caladea and Selawik are free fonts with the metrics of Calibri, Cambria and Segoe UI, so text wraps as in the original. Other fonts, Verdana or Tahoma for instance, need their own files, if their licence allows embedding. Nothing is installed in the image: the font files are part of your application, like the templates.

A Docker image

Publish the application with its templates and fonts, and copy the output into the ASP.NET runtime image:

<ItemGroup>
  <Content Include="Reports/**" CopyToOutputDirectory="PreserveNewest" />
</ItemGroup>

FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
WORKDIR /src
COPY . .
RUN dotnet publish -c Release -o /app

FROM mcr.microsoft.com/dotnet/aspnet:10.0
WORKDIR /app
COPY --from=build /app .
ENTRYPOINT ["dotnet", "InvoiceService.dll"]

No apt-get install step: no libgdiplus, no font packages.

Native AOT

Tagua compiles with native AOT, so the service can be a single native executable in the smallest runtime image:

<PropertyGroup>
  <PublishAot>true</PublishAot>
</PropertyGroup>

The native compiler needs clang and zlib in the build stage, and nothing in the runtime one:

FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
RUN apt-get update \
 && apt-get install -y --no-install-recommends clang zlib1g-dev
WORKDIR /src
COPY . .
RUN dotnet publish -c Release -o /app

FROM mcr.microsoft.com/dotnet/runtime-deps:10.0
WORKDIR /app
COPY --from=build /app .
ENTRYPOINT ["./InvoiceService"]

The migration guide covers what converts and what needs a person, and two worked examples show reports converted and rendered.