pyveci / racker Goto Github PK

Maybe add to "Prior Art" section.

• https://github.com/instantbox/instantbox
• https://github.com/instantbox/instantbox-images

Like vagrant up --provision, we might want to add this flag to the racker run command line in order to run re-provisioning of the WDM Vagrant machine.

When already having this flag, it can also be used to reset the checkout of the Windows Docker Machine repository.

https://github.com/cicerops/racker/blob/719ce6187ee44606e6ffa329d13d47353fc41b56/postroj/winrunner.py#L51-L53

We will need to employ caching at some spots. We are looking at using DiskCache here.

References:

• #5 (comment)
• #4 (review)

With #4, the Windows subsystem gets actually usable. However, it currently has three speed bumps when looking at optimizing the "time-to-shell" ¹.

A. Container image inspection

Before launching the container, we need to inspect its image in order to select which WDM host to use (Windows 2016, 2019, or 2022). On certain container images, we observed this can take up to three seconds when using skopeo inspect.

$ time skopeo --override-os=windows inspect --config --no-tags docker://docker.io/eclipse-temurin:18-jdk > /dev/null

real	0m3.262s
user	0m0.026s
sys	0m0.212s

We need to mitigate that speed bump, for example by caching the output of the skopeo inspect call. It will not be too difficult.

B. Container image adjustments

Currently, docker build is invoked on every invocation. Getting rid if it will save another 0.5 seconds.

C. PowerShell slowness

We are asking the community about any guidance on this matter. Does PowerShell really have such a large invocation overhead when compared to the cmd shell?

With the cmd program, it takes around 1.4 to 2.6 seconds to spawn a shell.

time racker run --rm --platform=windows/amd64 mcr.microsoft.com/windows/servercore:{ltsc2016,ltsc2019,ltsc2022} -- cmd /C exit

The powershell program takes around 3.1 to 4.7 seconds to spawn a shell.

time racker run --rm --platform=windows/amd64 mcr.microsoft.com/windows/servercore:{ltsc2016,ltsc2019,ltsc2022} -- powershell -Command exit

Add feature for bind-mounting a host directory.

It is important for being able to continue editing within your working tree on your workstation, while you will invoke the program(s) within the container, as usual.

About

Windows in a Docker container.

-- https://github.com/dockur/windows

Conceived by @kroese. Thanks!
Shared by @WalBeh. Thanks!

References

• GH-4