Proxy authentication from Ubuntu 24.04. fails for Install-PSResource with error code 407

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest image.
• Search the existing issues.
• Verified that this is not a Known Issue
• Verified this is not an issues in the underlying windows container that should be reported to Windows Feedback Hub

Steps to reproduce

Under powershell:preview-ubuntu-24.04, we cannot get NTLM authentication with our HTTP(S) proxy to work. Therefore, we cannot install PowerShell modules. We supply the proxy credentials via en environment variable (which seems to be picked up).

docker run -e ALL_PROXY="http://<username>:<pw>@<proxyfqdn>:8080" --rm --name pwsh -it mcr.microsoft.com/powershell:preview-ubuntu-24.04

I believe we are hitting https://github.com/dotnet/runtime/issues/100231. Our Wireshark capture shows a first CONNECT to the proxy to be initiated without authentication. A second CONNECT is initiated with a Proxy-Authorization header, but that still returns 407.

The Ubuntu 22.04 and Alpine 3.20 images behave differently, there the second CONNECT message is not send at all. I believe these hit NTLM authentication not working in Linux based environment · Issue #101058 · dotnet/runtime instead.

Proxy authentication under Windows works.

Expected behavior

Az Module is installed.

Actual behavior

PS /> [System.Net.Http.HttpClient]::DefaultProxy

Credentials
-----------
System.Net.Http.HttpEnvironmentProxyCredentials

PS /> Install-PSResource -Name Az -Scope CurrentUser

Untrusted repository
You are installing the modules from an untrusted repository. If you trust this repository, change its Trusted value by running the Set-PSResourceRepository cmdlet. Are you sure you want to install the
PSResource from 'PSGallery'?
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help (default is "N"): A
Install-PSResource: 'The proxy tunnel request to proxy 'http://<user>:<pw>@<proxyfqdn>:8080/' failed with status code '407'."' Request sent: 'https://www.powershellgallery.com/api/v2/FindPackagesById()?%24filter=Id+eq+%27Az%27+and+IsLatestVersion+eq+true&%24inlinecount=allpages&id=%27Az%27'
Install-PSResource: Package(s) 'Az' could not be installed from repository 'PSGallery'.

Error details

PS /> Get-Error

Exception             :
    Type    : Microsoft.PowerShell.PSResourceGet.UtilClasses.ResourceNotFoundException
    Message : Package(s) 'Az' could not be installed from repository 'PSGallery'.
    HResult : -2146233088
TargetObject          : Microsoft.PowerShell.PSResourceGet.Cmdlets.InstallPSResource
CategoryInfo          : InvalidData: (Microsoft.PowerShel…s.InstallPSResource:InstallPSResource) [Install-PSResource], ResourceNotFoundException
FullyQualifiedErrorId : InstallPackageFailure,Microsoft.PowerShell.PSResourceGet.Cmdlets.InstallPSResource
InvocationInfo        :
    MyCommand        : Install-PSResource
    ScriptLineNumber : 1
    OffsetInLine     : 1
    HistoryId        : 3
    Line             : Install-PSResource -Name Az -Scope CurrentUser
    Statement        : Install-PSResource -Name Az -Scope CurrentUser
    PositionMessage  : At line:1 char:1
                       + Install-PSResource -Name Az -Scope CurrentUser
                       + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    InvocationName   : Install-PSResource
    CommandOrigin    : Internal
ScriptStackTrace      : at <ScriptBlock>, <No file>: line 1
PipelineIterationInfo :
      0
      1

Environment data

{
        "schemaVersion": 2,
        "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
        "config": {
                "mediaType": "application/vnd.docker.container.image.v1+json",
                "size": 5572,
                "digest": "sha256:ca17b51e4e0fbd04c97c1a6ee9109a505c425f63a8c9ca1b80a6c908035a74c5"
        },
        "layers": [
                {
                        "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
                        "size": 29751968,
                        "digest": "sha256:de44b265507ae44b212defcb50694d666f136b35c1090d9709068bc861bb2d64"
                },
                {
                        "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
                        "size": 103040902,
                        "digest": "sha256:94058be39bdeb7bdadb5c92c6d989191e021a35d7d7a24d27f5fbe1cce3439d6"
                }
        ]
}

Visuals

No response

Start by reproducing the docker run command with the proxy environment variable on the preview-ubuntu-24.04 image, then compare it with the Ubuntu 22.04 and Alpine 3.20 images. Investigate the NTLM proxy behavior described in the linked dotnet/runtime issues; done means Install-PSResource -Name Az succeeds through the authenticated proxy.