Create Linux TeamCity Agent with .NET 6.0 RC2

Dockerfile

FROM jetbrains/teamcity-agent:latest
ARG DEBIAN_FRONTEND=noninteractive

USER root
RUN apt-get update && apt-get install -y --no-install-recommends apt-utils
RUN apt-get update

# remove previous dotnet from teamcity-agent install
RUN rm /usr/bin/dotnet \
    && rm -rf /usr/share/dotnet \
    && mkdir -p /usr/share/dotnet/shared

# (runtime) from https://github.com/dotnet/dotnet-docker/blob/main/src/runtime/6.0/bullseye-slim/amd64/Dockerfile
RUN curl -SL --output dotnet.tar.gz https://dotnetcli.azureedge.net/dotnet/Runtime/6.0.0-rc.2.21480.5/dotnet-runtime-6.0.0-rc.2.21480.5-linux-x64.tar.gz \
    && dotnet_sha512='45062417c6111af4d635868927e8f69d43f66c9e0f111cb71c1861eaf5ceda4aefa99d97c6ce3b13fac2bc7c57c435e6f8b2d43c51a3bb3304b42081d98f7047' \
    && echo "$dotnet_sha512  dotnet.tar.gz" | sha512sum -c - \
    && mkdir -p /dotnet \
    && tar -ozxf dotnet.tar.gz -C /usr/share/dotnet \
    && rm dotnet.tar.gz
ENV DOTNET_VERSION=6.0.0-rc.2.21480.3
RUN ln -s /usr/share/dotnet/dotnet /usr/bin/dotnet

# (aspnetcore) from https://github.com/dotnet/dotnet-docker/blob/main/src/aspnet/6.0/bullseye-slim/amd64/Dockerfile
# Retrieve ASP.NET Core
RUN curl -SL --output aspnetcore.tar.gz https://dotnetcli.azureedge.net/dotnet/aspnetcore/Runtime/6.0.0-rc.2.21480.10/aspnetcore-runtime-6.0.0-rc.2.21480.10-linux-x64.tar.gz \
    && aspnetcore_sha512='d48895237644a3999663b2e16baa2303d8b77f66385a04d8edb5601fdffacce18b1b1318827d09f74f6b133ff2c179ef659bd21cf8460289b5f81f404fa8b326' \
    && echo "$aspnetcore_sha512  aspnetcore.tar.gz" | sha512sum -c - \
    && tar -ozxf aspnetcore.tar.gz ./shared/Microsoft.AspNetCore.App -C /usr/share/dotnet/shared/Microsoft.AspNetCore.App \
    && rm aspnetcore.tar.gz

# (sdk) from https://github.com/dotnet/dotnet-docker/blob/main/src/sdk/6.0/focal/amd64/Dockerfile
ENV \
    # Unset ASPNETCORE_URLS from aspnet base image
    ASPNETCORE_URLS= \
    # Do not generate certificate
    DOTNET_GENERATE_ASPNET_CERTIFICATE=false \
    # Do not show first run text
    DOTNET_NOLOGO=true \
    # SDK version
    DOTNET_SDK_VERSION=6.0.100-rc.2.21505.57 \
    #DOTNET_SDK_VERSION=6.0.0-rc.2.21480.5 \
    # Enable correct mode for dotnet watch (only mode supported in a container)
    DOTNET_USE_POLLING_FILE_WATCHER=true \
    # Unset Logging__Console__FormatterName from aspnet base image
    Logging__Console__FormatterName= \
    # Skip extraction of XML docs - generally not useful within an image/container - helps performance
    NUGET_XMLDOC_MODE=skip \
    # PowerShell telemetry for docker image usage
    POWERSHELL_DISTRIBUTION_CHANNEL=PSDocker-DotnetSDK-Ubuntu-20.04

RUN apt-get update \
    && apt-get install -y --no-install-recommends \
        curl \
        git \
        wget \
    && rm -rf /var/lib/apt/lists/*

# Install .NET SDK
RUN curl -SL --output dotnet.tar.gz https://dotnetcli.azureedge.net/dotnet/Sdk/$DOTNET_SDK_VERSION/dotnet-sdk-$DOTNET_SDK_VERSION-linux-x64.tar.gz \
    && dotnet_sha512='0a8f85a2757f61ca7f9b8c546af4554c2aac9cdb06f6d62879a60de6f2a3d37ea7136f48896c9c85828a2d55df354e7b9b5b4dc22896c927f0c6370a5ade1b9c' \
    && echo "$dotnet_sha512  dotnet.tar.gz" | sha512sum -c - \
    && mkdir -p /usr/share/dotnet \
    && tar -C /usr/share/dotnet -oxzf dotnet.tar.gz ./packs ./sdk ./sdk-manifests ./templates ./LICENSE.txt ./ThirdPartyNotices.txt \
    && rm dotnet.tar.gz \
    # Trigger first run experience by running arbitrary cmd
    && dotnet help

# Install PowerShell global tool
RUN powershell_version=7.2.0-preview.10 \
    && curl -SL --output PowerShell.Linux.x64.$powershell_version.nupkg https://pwshtool.blob.core.windows.net/tool/$powershell_version/PowerShell.Linux.x64.$powershell_version.nupkg \
    && powershell_sha512='bcf4cb050215742e08a31079b85b9289955017c91a6c6c5bb2865b0ff5c9a967422c9c5235b0e38329d2d44fd2d1c40922f55371df782ed7e44fdf048c229a0a' \
    && echo "$powershell_sha512  PowerShell.Linux.x64.$powershell_version.nupkg" | sha512sum -c - \
    && mkdir -p /usr/share/powershell \
    && dotnet tool install --add-source / --tool-path /usr/share/powershell --version $powershell_version PowerShell.Linux.x64 \
    && dotnet nuget locals all --clear \
    && rm PowerShell.Linux.x64.$powershell_version.nupkg \
    && ln -s /usr/share/powershell/pwsh /usr/bin/pwsh \
    && chmod 755 /usr/share/powershell/pwsh \
    # To reduce image size, remove the copy nupkg that nuget keeps.
    && find /usr/share/powershell -print | grep -i '.*[.]nupkg$' | xargs rm

ENV TEAMCITY_AGENT_HOME=/opt/buildAgent/