FileArchive creates zip files with backslashes on Windows

[stevebutler]

What happened?

In a Pulumi Python project, on a Windows 11 computer, I created an S3 bucket object based on an AssetArchive containing a FileArchive. The Pulumi update was successful, and the zip file was present in S3. An AWS CodeBuild project takes the zip file as its source, running on "aws/codebuild/amazonlinu2-x86_64-standard:5.0".

On the Linux host, I expected the "ls -R" command to show a nested directory tree. Instead, it showed a list of files with backslashes in their names.

I downloaded the zip file to Windows 11, and both Explorer and 7zip open the file and show the nested directory tree with no complaints. Opening the zip file in Notepad++, I see backslashes in filenames.

Example

ansible_bundle = aws.s3.BucketObject(
    resource_name="AnsibleBundleZip",
    key="codebuild-src/ansible-bundle.zip",
    bucket=deployment.src_bucket_id,
    source=pulumi.AssetArchive({
        ".": pulumi.FileArchive("AnsibleBundle"),
    }),
    server_side_encryption='AES256'
)

Output of pulumi about

pulumi about
CLI
Version 3.117.0
Go Version go1.22.3
Go Compiler gc

Plugins
KIND NAME VERSION
resource aws 6.37.1
resource aws-native 0.103.0
language python unknown

Host
OS Microsoft Windows 11 Enterprise
Version 10.0.22631 Build 22631
Arch x86_64

This project is written in python: executable='C:\projects\bit\poetry-demo.venv\Scripts\python.exe' version='3.12.3'
[...]

Additional context

A similar bug (#2784) was fixed five years ago.

Contributing

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[justinvp]

Thanks for opening the issue @stevebutler and sorry for the trouble. I was able to reproduce this behavior by running the following test on Windows and removing the filepath.ToSlash calls around the actual values.

pulumi/sdk/go/common/resource/asset_test.go

Lines 584 to 586 in 98d7246

	assert.Equal(t, "foo/a.txt", filepath.ToSlash(files[0].Name))
	assert.Equal(t, "foo/bar/b.txt", filepath.ToSlash(files[1].Name))
	assert.Equal(t, "fake.txt", filepath.ToSlash(files[2].Name))

I would expect the names to be using forward slashes, but looks like they are not. I haven't had a chance to dig deeper yet.

[justinvp]

Looks like the problem is here:

pulumi/sdk/go/common/resource/archive/archive.go

Lines 366 to 367 in 98d7246

	// The subarchive produced a valid blob. Return it.
	return filepath.Join(r.archiveRoot, name), blob, nil

That is going to produce file names in the zip with back slashes on Windows, which is not what we want. That should be wrapped in filepath.ToSlash to avoid including back slashes in the name.