Cannot login if windows has set a PAC file

[nc-niva]

Description

I'm using a PAC file, exposed by a docker container.
That PAC file configured in windows under proxy setting.

The content of the pac file is this

function FindProxyForURL(url, host) {
   // Check if the URL is an HTTPS connection and the domain ends with ccta.dk
   if (shExpMatch(host, "*.XXXX.dk")) {
       return "PROXY 127.0.0.1:8888";
   }
   else if (shExpMatch(host, "*.YYYY.XXXX.dk")) {
	   return "PROXY 127.0.0.1:8888";
   }
   // For all other URLs, bypass the proxy
   return "DIRECT";
}

It has nothing to do with docker.

And the mime type is ´application/x-ns-proxy-autoconfig´

Reproduce

Setup a pac file in your windows proxy settings.
Wait 24 hours (or delete all your cached stuff, to ensure you are logged out),
Try to log in. -> This will hang forever and eventually timeout.

To fix it: disable pac file setting in windows proxy settings, restart docker and login.

Expected behavior

No response

docker version

Client:
 Version:           27.4.0
 API version:       1.47
 Go version:        go1.22.10
 Git commit:        bde2b89
 Built:             Sat Dec  7 10:40:21 2024
 OS/Arch:           windows/amd64
 Context:           desktop-linux

Server: Docker Desktop 4.37.1 (178610)
 Engine:
  Version:          27.4.0
  API version:      1.47 (minimum version 1.24)
  Go version:       go1.22.10
  Git commit:       92a8393
  Built:            Sat Dec  7 10:38:57 2024
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.7.21
  GitCommit:        472731909fa34bd7bc9c087e4c27943f9835f111
 runc:
  Version:          1.1.13
  GitCommit:        v1.1.13-0-g58aa920
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info

Client:
 Version:    27.4.0
 Context:    desktop-linux
 Debug Mode: false
 Plugins:
  ai: Ask Gordon - Docker Agent (Docker Inc.)
    Version:  v0.5.1
    Path:     C:\Program Files\Docker\cli-plugins\docker-ai.exe
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.19.2-desktop.1
    Path:     C:\Program Files\Docker\cli-plugins\docker-buildx.exe
  compose: Docker Compose (Docker Inc.)
    Version:  v2.31.0-desktop.2
    Path:     C:\Program Files\Docker\cli-plugins\docker-compose.exe
  debug: Get a shell into any image or container (Docker Inc.)
    Version:  0.0.37
    Path:     C:\Program Files\Docker\cli-plugins\docker-debug.exe
  desktop: Docker Desktop commands (Beta) (Docker Inc.)
    Version:  v0.1.0
    Path:     C:\Program Files\Docker\cli-plugins\docker-desktop.exe
  dev: Docker Dev Environments (Docker Inc.)
    Version:  v0.1.2
    Path:     C:\Program Files\Docker\cli-plugins\docker-dev.exe
  extension: Manages Docker extensions (Docker Inc.)
    Version:  v0.2.27
    Path:     C:\Program Files\Docker\cli-plugins\docker-extension.exe
  feedback: Provide feedback, right in your terminal! (Docker Inc.)
    Version:  v1.0.5
    Path:     C:\Program Files\Docker\cli-plugins\docker-feedback.exe
  init: Creates Docker-related starter files for your project (Docker Inc.)
    Version:  v1.4.0
    Path:     C:\Program Files\Docker\cli-plugins\docker-init.exe
  sbom: View the packaged-based Software Bill Of Materials (SBOM) for an image (Anchore Inc.)
    Version:  0.6.0
    Path:     C:\Program Files\Docker\cli-plugins\docker-sbom.exe
  scout: Docker Scout (Docker Inc.)
    Version:  v1.15.1
    Path:     C:\Program Files\Docker\cli-plugins\docker-scout.exe

Server:
 Containers: 3
  Running: 1
  Paused: 0
  Stopped: 2
 Images: 40
 Server Version: 27.4.0
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 CDI spec directories:
  /etc/cdi
  /var/run/cdi
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 nvidia runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 472731909fa34bd7bc9c087e4c27943f9835f111
 runc version: v1.1.13-0-g58aa920
 init version: de40ad0
 Security Options:
  seccomp
   Profile: unconfined
 Kernel Version: 5.15.153.1-microsoft-standard-WSL2
 Operating System: Docker Desktop
 OSType: linux
 Architecture: x86_64
 CPUs: 12
 Total Memory: 31.35GiB
 Name: docker-desktop
 ID: 8accf29f-864b-4279-824e-33e215a39e83
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: http.docker.internal:3128
 HTTPS Proxy: http.docker.internal:3128
 No Proxy: hubproxy.docker.internal
 Labels:
  com.docker.desktop.address=npipe://\\.\pipe\docker_cli
 Experimental: false
 Insecure Registries:
  hubproxy.docker.internal:5555
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: No blkio throttle.read_bps_device support
WARNING: No blkio throttle.write_bps_device support
WARNING: No blkio throttle.read_iops_device support
WARNING: No blkio throttle.write_iops_device support
WARNING: daemon is not using the default seccomp profile

Diagnostics ID

1AB300DC-8534-4703-83D4-8D23963ACED1/20250129064636

Additional Info

No response

[thaJeztah]

Thanks for reporting; I forwarded this internally to some colleagues working on things related to proxy-configuration; they informed me that there's an internal ticket (DDB-188) that could be related.

I don't have an ETA on this, but at least it looks like it's on our radar, and possibly your reproducer could help (thanks for that!)

[thaJeztah]

(marked this as "acknowledged", per the above, but it's to be confirmed if it's the same issue as tracked there)

[karman-docker]

@nc-niva would you be able to provide a log file following the steps mentioned below please.

1. Quit Docker Desktop and clear Docker relarted cached credentials (from credential manager)
2. Enable PAC file in Windows proxy settings.
3. Launch Docker and attempt to login. If it hangs, run the below command:
   "C:\Program Files\Docker\Docker\resources\com.docker.diagnose.exe" getstacks

Output will be written to a file called backendstacks.log either in the current directory or under %APPDATA%/Docker/ directory. Thank you.

[nc-niva]

Here you go @karman-docker

backendstacks.log

[nc-niva]

sidenote: it works in docker desktop version 4.35.1

[karman-docker]

Thanks @nc-niva based on that log, I can confirm that it is the same issue as mentioned by @thaJeztah. We are investigating it.

[nc-niva]

I (obviously) don't know how you guys are working, but do you have some sort of ETA on it?
We are a lot of people (~50) who doesn't update docker due to this

[karman-docker]

Hi @nc-niva
We understand your concern and are prioritizing this issue. While we don’t have an ETA yet as the investigation is still ongoing, we will share any updates as soon as they become available.

[karman-docker]

Hi @nc-niva,
An update on this issue. A fix has been merged into our codebase and will be included in the upcoming release.