Dotnet-docker: dotnet-core and Powershell-core in one image

[WernerMairl]

preface: i'm new on docker/linux....

my requirement: a docker (linux) image where dotnet (sdk) and Powershell-Core is available together.
it is really difficult to do that currently because of different base images (jessie/stretch/xenial)
different installation prerequisites etc....

With the latest Powershell beta relase (a few days old) a debian package (jessie) was available the first time and i was able to compile a image, but i'm not sure if my dockerfile-implementation was the best way (lot of hacks and i'm new on docker/linux)
Anyone can provide a docker file for that scenario - assuming there is a lot of reasons to combine this two products...

or another idea:

please prepare the dotnet-sdk package in a way that i must only "apt-get install powershell" inside my own image.
assuming that most/all of the installation prerequisites are identical for dotnet-core and PS-Core....

regards
Werner

[Boggin]

I'm looking to do something similar. In my testing so far I've used the Dockerfile for the 2.0.0-sdk-stretch image.
PS> iwr https://raw.githubusercontent.com/dotnet/dotnet-docker/master/2.0/sdk/stretch/amd64/Dockerfile -o Dockerfile
PS> docker build .

To check I can run PowerShell on this I've opened a command prompt and done a simple install.
PS> docker run -it <container_id>
root# wget https://github.com/PowerShell/PowerShell/releases/download/v6.0.0-beta.8/powershell_6.0.0-beta.8-1.debian.9_amd64.deb
root# dpkg -i powershell_6.0.0-beta.8-1.debian.9_amd64.deb

Quick test to see if that works:
root# powershell
PS> get-date
PS> exit

Commit your changes to a new image:
PS> docker commit <container_id> your-name-here/dotnet-powershell

I can now use my new image and it has PowerShell along with dotnet core 2.0.0 SDK.

The other option is to modify the Dockerfile with the instructions for installing PowerShell.

[MichaelSimons]

You could easily put @Boggin's steps into a Dockerfile to make it easier to build.

FROM microsoft/dotnet:2.0.0-sdk

RUN curl -SL https://github.com/PowerShell/PowerShell/releases/download/v6.0.0-beta.8/powershell_6.0.0-beta.8-1.debian.9_amd64.deb --output powershell.deb\
    && dpkg -i powershell.deb \
    && rm powershell.deb

This makes use of the .NET image so that you don't have to rebuild it and can share the Docker layers.

[Boggin]

I tested @MichaelSimons suggestion with the addition of making PowerShell the default shell (an idea from the microsoft/powershell Dockerfile) and it worked just fine.

# Install PowerShell Core 6.0
ENV POWERSHELL_DOWNLOAD_URL https://github.com/PowerShell/PowerShell/releases/download/v6.0.0-beta.8/powershell_6.0.0-beta.8-1.debian.9_amd64.deb

RUN curl -SL $POWERSHELL_DOWNLOAD_URL --output powershell.deb \
    && dpkg -i powershell.deb \
    && rm powershell.deb

# Use PowerShell as the default shell
# Use array to avoid Docker prepending /bin/sh -c
CMD [ "powershell" ]

[WernerMairl]

Thanks a lot for all that suggestions!

My "stretch" sample is up and running by using suggestions from the first two answers/posts from Boggin and MichaelSimons!!

Now i'm working on a sample with jessie using this instructions for installing powershell.

here my dockerfile:

FROM microsoft/dotnet:2.0.0-sdk-jessie

RUN apt-get update && apt-get -y install apt-utils
RUN apt-get update && apt-get -y install curl apt-transport-https

RUN curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add -
RUN sh -c 'echo "deb [arch=amd64] https://packages.microsoft.com/repos/microsoft-debian-jessie-prod jessie main" > /etc/apt/sources.list.d/microsoft.list'
RUN apt-get update && apt-get -y install powershell

Powershell is working after that but i see some red lines during compiling => any idea ?
not sure if that "RUN sh -c...." is the best way to do that in a dockerfile.

i like this way for the moment because it avoids the download path literals used in the other samples....

regards
Werner

[tuananh]

@WernerMairl i think you can just trim it to

RUN echo "deb [arch=amd64] https://packages.microsoft.com/repos/microsoft-debian-jessie-prod jessie main" > /etc/apt/sources.list.d/microsoft.list

[WernerMairl]

@tuananh thank you, that works!

i have stil the following red lines during docker build - but the build completes with success and PS is working - any idea from the linux experts?

debconf: unable to initialize frontend: Dialog
debconf: (TERM is not set, so the dialog frontend is not usable.)
debconf: falling back to frontend: Readline
debconf: unable to initialize frontend: Readline
debconf: (This frontend requires a controlling tty.)
debconf: falling back to frontend: Teletype
dpkg-preconfigure: unable to re-open stdin:

[tuananh]

@WernerMairl can you try to RUN export TERM=xterm or maybe set environment variable after FROM

FROM microsoft/dotnet:2.0.0-sdk-jessie
ENV TERM=xterm

[MichaelSimons]

@WernerMairl, I think you may need to set DEBIAN_FRONTEND to noninteractive. Also I you may want to consider cleaning up the apt cache so that your resulting image is smaller. See the Dockerfile Best Practices for more details.

FROM microsoft/dotnet:2.0.0-sdk-jessie

ENV DEBIAN_FRONTEND noninteractive

# Install PowerShell pre-reqs
RUN apt-get update \
    && apt-get -y install \
        apt-utils \
        curl \
        apt-transport-https \
    && rm -rf /var/lib/apt/lists/*

# Install PowerShell
RUN curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - \
    && echo "deb [arch=amd64] https://packages.microsoft.com/repos/microsoft-debian-jessie-prod jessie main" > /etc/apt/sources.list.d/microsoft.list \
    && apt-get update \
    && apt-get -y install \
        powershell \
    && rm -rf /var/lib/apt/lists/*

[MichaelSimons]

@WernerMairl feel free to close this issue if you feel your questions have been answered - thanks.

[WernerMairl]

Thank you - sample up and running!
regards
Werner