Windows build 1809 compatibility

[jwlogemann]

I've changed the Dockerfile to be Windows build 1809 compatible. This is needed when using Traefik as a Kubernetes ingress controller in Windows Server 2019

Fixes #44

[zlepper]

I can confirm that it seems to be working. It is at least both building and running.

For anyone currious why the "netapi32" file is there, it's to fix: golang/go#21867

[Barsonax]

Any ETA when this is getting merged?

[dduportal]

• For the Docker image name change: it should be done in the file tmpl.Dockerfile instead of here
• For the tag (version) change, it should be done in the scripts update*.sh as they generate these Dockerfiles from the templates.

[dduportal]

This file should be downloaded in the same manner as traefik.exe is, so it can be updated when the update*.sh scripts are called.

[dduportal]

Hi @jwlogemann, thanks for this contribution, it's cool!

This PR is currently being blocked for the following reasons:

• As you figured out (and implemented in this PR), the library netapi32.dll is missing in the Docker based image of nanoserver, since nanoserver-18.03. This library is required for Traefik (thanks @zlepper to point the thread in net: lookup_windows.go uses APIs that are no longer in Nano Server golang/go#21867 to us). So this is a dependency for the Windows-based Docker image for Traefik:
  • It has to be tracked and updatable (because it's a dependency with it's own lifecycle)
  • It has to be trusted (at least the retrieving method should use an official source)
  • It has to be specified only for declination that requires it (nanoserver:sac2016 doesn't for example)

Alas, by committing directly the binary as this PR, neither of these 3 elements are fulfilled, which would (at least) make the image refused by Docker when trying to publish it.

What should we do then?

Well, TL;DR; we have to wait for docker-library/official-images#5929 to be ready.

Details:

• @StefanScherer is doing a great job at providing different declinations of Windows-based Docker images for Traefik here: https://github.com/StefanScherer/dockerfiles-windows/tree/master/traefik. He's solving the challenge of the netapi32.dll by using a Multi-Stage Docker build.
• As the Traefik Docker image is built by Docker's library for official images, there is no Multi-stages build support, neither any "2 steps" builds documented as for today (ref. [WIP] Multi-stage build #14 ).
• As for today, updating this repository utilises shell scripts (update*.sh) which download the right Traefik binaries, extracts dependencies for Alpine-based images (certificates) and generates Dockerfiles according to the version of Traefik to be released. This process is run under a Linux machine (Travis, smeaphore, or contributor), so it ain't easy to retrieve the DLL:
  • No Docker Windows Engine, so no way to docker run/build to extract the file.
  • Extracting the tar image with tools like skopeo would be a pain as the Windows image are Gigabytes-sized...

Proposal: blocking this PR until Multi-stage build are supported in Docker's official library.

[jorisscheppers]

Proposal: blocking this PR until Multi-stage build are supported in Docker's official library.

As docker-library/official-images#5929 has recently been merged, can work on this PR continue? I would really like to see Traefik work on Windows Server 2019!

[dduportal]

Yes totally, let's update this PR following the new bashbrew!