PowerShell Core on smaller Linux distributions (eg. Alpine)

[pcgeek86]

I'd like to try to get PowerShell Core working on Alpine Linux, with the long term goal of being able to run lightweight PowerShell Core Docker containers. The Docker container images I built using Ubuntu 16 and CentOS 7 are a bit on the large side.

So far, we know the following:

• .NET Core is included with the PowerShell Core distributions
• .NET Core has a dependency on libicu52 and libunwind8

What we need to figure out:

• How to install or compile libicu52 on Alpine Linux
• How to install or compile libunwind8 on Alpine Linux
• How to install or compile PowerShell Core binaries on Alpine Linux

Anyone want to provide some insight to this effort?

Cheers,
Trevor Sullivan
Docker Captain
Microsoft MVP: Cloud & Data Center Management
https://trevorsullivan.net
https://twitter.com/pcgeek86

[colemickens]

Seems like you need .NET Core for Alpine first: https://github.com/dotnet/coreclr/issues/917

[dyrnade]

For libicu52 : https://pkgs.alpinelinux.org/package/edge/main/x86_64/icu-libs
For libunwind8 : https://pkgs.alpinelinux.org/package/edge/main/x86_64/libunwind

You can search for anything on https://pkgs.alpinelinux.org/packages with regex.
So i search the libs like icu , unwind
But i am not sure whether they are the one you wanted or not..

Have fun...

[ghost]

We ported couple of libraries along the way such as lldb, then @benpye did the libunwind and @mjeanson blessed us with liblttng-ust on Alpine Linux via aports packaging system. I also made some strides on the xbps front (package manager for Void Linux, which ships with two variants: musl-libc and glibc) and requested those fellas to add couple of related patches and libs to unblock CoreCLR build. As a result, CoreCLR up until very recently, was building on Alpine Linux as well as Void Linux (musl) and passing all the "PAL tests". Due to a recent change in CoreCLR code base, there is a blocker I am hitting https://github.com/dotnet/coreclr/issues/917#issuecomment-236907708 and hence the progress has been scrambled. Hopefully it won't stay like that for very long.

[pcgeek86]

So, I talked with the .NET team, and discovered that there's a microsoft/dotnet:core image that's only 250 MB. By inspecting the Dockerfile for .NET Core dependencies, I was able to produce a smaller Docker image for PowerShell Core, than what was possible with Ubuntu and CentOS 7. I used the Dockerfile statements from the .NET Core dependencies base image, and extended it to include PowerShell Core from a local build context. That avoided the need to install curl or wget along with extra dependencies.

Now, the Docker image based on Debian Jessie is only 334.3 MB.

https://twitter.com/pcgeek86/status/769239625047035904
https://hub.docker.com/r/trevorsullivan/powershell/

PS C:\Users\TrevorSullivan\PowerShellCore> docker images trevorsullivan/powershell
REPOSITORY                  TAG                 IMAGE ID            CREATED             SIZE
trevorsullivan/powershell   jessie              4abfcbcdfcf8        16 minutes ago      334.3 MB
trevorsullivan/powershell   centos7             6d7da3eb764b        7 days ago          571.5 MB
trevorsullivan/powershell   latest              3cbb7892a31c        8 days ago          537.1 MB

It's still not as small as we could get with Alpine Linux, but it's a huge improvement.

[andschwa]

@pcgeek86 do our new containers fit your need?

[ghost]

fyi Alpine discussion continued here https://github.com/PowerShell/PowerShell/issues/4605, anyone wants to chime with a docker, now is the time!