Implement gz compression

[eerhardt]

Compressing the .tar files to make the layer files smaller.

Fix #29

cc @rainersigwald

Are there other tests I should be adding / modifying?

[rainersigwald]

Thanks!

[eerhardt]

Are there instructions to manually test this out myself? Or are the automated tests good enough?

[rainersigwald]

@benvillalobos do you have the manual use-just-built-package steps written down? If not can you?

[rainersigwald]

However I'd expect the push-to-local-Docker-registry tests to exercise this codepath--if you can validate that with a breakpoint @eerhardt I think we'd be good to move forward.

[baronfel]

We should add something to to devguide here, but my overall process is:

• have a machine-level nuget source: dotnet nuget add source <PATH> -n local
• build this repo and note the package path and version
• push the generated package to the local source: dotnet nuget push <path to nupkg> -s local
• in a test project add the new package version: dotnet add package Microsoft.NET.Build.Containers --version <version>
• publish the test project (probably with a binlog): dotnet publish -p:PublishProfile=DefaultContainer --os linux --arch x64 -c Release -bl

one downside to this is that you pollute your global nuget cache with the intermediate packages, but that's a failing of the overall nuget cache design and not something we can really mitigate. just gotta purge it every so often I suppose.

[eerhardt]

However I'd expect the push-to-local-Docker-registry tests to exercise this codepath--if you can validate that with a breakpoint @eerhardt I think we'd be good to move forward.

This test was definitely broken when my code wasn't working:

sdk-container-builds/Test.Microsoft.NET.Build.Containers.Filesystem/EndToEnd.cs

Lines 15 to 50 in da83f2f

	public async Task ApiEndToEndWithRegistryPushAndPull()
	{
	string publishDirectory = await BuildLocalApp();
	// Build the image
	Registry registry = new Registry(new Uri($"http://{DockerRegistryManager.LocalRegistry}"));
	Image x = await registry.GetImageManifest(DockerRegistryManager.BaseImage, DockerRegistryManager.BaseImageTag);
	Layer l = Layer.FromDirectory(publishDirectory, "/app");
	x.AddLayer(l);
	x.SetEntrypoint(new [] {"/app/MinimalTestApp" });
	// Push the image back to the local registry
	await registry.Push(x, NewImageName, "latest", DockerRegistryManager.BaseImage);
	// pull it back locally
	Process pull = Process.Start("docker", $"pull {DockerRegistryManager.LocalRegistry}/{NewImageName}:latest");
	Assert.IsNotNull(pull);
	await pull.WaitForExitAsync();
	Assert.AreEqual(0, pull.ExitCode);
	// Run the image
	ProcessStartInfo runInfo = new("docker", $"run --rm --tty {DockerRegistryManager.LocalRegistry}/{NewImageName}:latest");
	Process run = Process.Start(runInfo);
	Assert.IsNotNull(run);
	await run.WaitForExitAsync();
	Assert.AreEqual(0, run.ExitCode);
	}

We should add something to to devguide here

I can try out these steps and submit a PR to update the dev guide.

[benvillalobos]

@rainersigwald I do not! The steps would be in our E2E tests. Something very close to:

dotnet new webapi -f net7.0
dotnet new nugetconfig
dotnet add source path/to/local/folder-for-nuget-source --name foo Create a local source to push to
dotnet nuget push path/to/this-repo/bin/Microsoft.NET.Build.Containers.nupkg --source foo Push package to that local folder source.
dotnet add package add Microsoft.NET.Build.Containers --prerelease Add the package to your test project. NOTE: This will also add it to your nuget cache, so you'll need to clear this package after each test.
dotnet publish /p:publishprofile=defaultcontainer /p:runtimeidentifier=linux-x64 /p:ContainerBaseImage=<> /p:ContainerRegistry=<> /p:ContainerImageName=<> /p:Version=<> /bl

This is how I went about testing before we had UT's, starting from scratch.

cc @eerhardt

edit: looks like I missed #154 :)

[carlossanlop]

LGTM. Nothing blocking. Left 3 questions.

[carlossanlop]

@rainersigwald I know this was before the PR, but I'm not understanding this comment clearly: Is /app being prefixed or suffixed to the file path?

I ask because if it's a prefix, and it needs to be removed, we could try using the stream-based TarFile.CreateFromDirectory with includeBaseDirectory=false, see if that works.

If that's not what the comment meant, then nothing to do here.

[eerhardt]

I was able to test this end-to-end with a basic ASP.NET app that uses ML.NET (using the above instructions).

Using the 1.8.0 version from nuget.org, the .tar file in my %TEMP%\Containers\Content is 15.8 MB.

Using my local build of this PR with the exact same app, the .tar file in my %TEMP%\Containers\Content is 4.58 MB.

[eerhardt]

Any thoughts on when this can be merged?

[baronfel]

This LGTM and @rainersigwald approved, so I'm merging.