For the life of me I can't figure out what is going on. I created a brand new empty Umbraco 13 project. Created the Dockerfile below. When I push the site to AppRunner, the front page loads up just fine. When I attempt to go to /umbraco the site gets stuck in a redirect loop. I commented out the nodejs garbage because it was taking forever to build. Also, wasn't necessary for my build.

FROM mcr.microsoft.com/dotnet/aspnet:8.0 AS base
#USER app
WORKDIR /app
EXPOSE 8080

FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
WORKDIR /src
COPY ["UmbracoAppRunnerDeployment/UmbracoAppRunnerDeployment.csproj", "UmbracoAppRunnerDeployment/"]
RUN dotnet restore "UmbracoAppRunnerDeployment/UmbracoAppRunnerDeployment.csproj"
COPY . .
WORKDIR "/src/UmbracoAppRunnerDeployment"
RUN dotnet build "UmbracoAppRunnerDeployment.csproj" -c Release -o /app/build

FROM build AS publish
# RUN apt-get update -yq \
#     && apt-get install -yq ca-certificates curl gnupg \
#     && mkdir -p /etc/apt/keyrings \
#     && curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg \
#     && echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_18.x nodistro main" | tee /etc/apt/sources.list.d/nodesource.list \
#     && apt-get update -yq \
#     && apt-get install nodejs -yq
RUN dotnet publish "UmbracoAppRunnerDeployment.csproj" -c Release -o /app/publish

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "UmbracoAppRunnerDeployment.dll"]

https://cdn.discordapp.com/attachments/1241116074473422909/1241116075010297966/Designer_1.jpeg?ex=664906eb&is=6647b56b&hm=dff58dfb2ef28c0cf03b77a46b21eeafedbe8014febe8746ec1bffc6825f216c&

I believe /umbraco/ forces a redirect to https, which could lead redirect loops if the server also forces https (or something like that, not entirely sure anymore)