YARP WithStaticFiles + WithDockerfile: missing docs on required /wwwroot path in Docker image

[maddymontaquila]

Bug Description

When using AddYarp("frontend").WithStaticFiles().WithDockerfile("./frontend"), there is no documentation explaining that the YARP container expects static files at /wwwroot. Users must write a multi-stage Dockerfile that copies built assets to /wwwroot using the mcr.microsoft.com/dotnet/nightly/yarp base image, but this is not documented anywhere.

Current Behavior

A user creates a Dockerfile that builds frontend assets (e.g., Vite/React) but doesn't know where to place the output. The container starts successfully but returns 404 for all requests. The only clue is a log line: The WebRootPath was not found: /wwwroot. Static files may be unavailable.

Expected Behavior

The YARP integration docs should document:

1. That WithStaticFiles() expects files at /wwwroot inside the container
2. A complete example Dockerfile showing the required multi-stage build pattern, e.g.:

FROM node:22-slim AS build
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM mcr.microsoft.com/dotnet/nightly/yarp
COPY --from=build /app/dist /wwwroot

3. That the Dockerfile must use the YARP base image (mcr.microsoft.com/dotnet/nightly/yarp) as its final stage so dotnet /app/yarp.dll can run

Page URL

The YARP hosting integration page (if it exists) or the general deployment docs.

Additional Context

• Aspire version: 13.3.0-pr.14149.g4bc5e9bf (all packages)
• .NET SDK: 10.0.100
• OS: macOS (Darwin arm64)
• Discovered during aspire deploy to Azure Container Apps