Port conflict of WSL2 with CRC for SSH (usermode networking)

[gbraad]

Issue Description

With the recent introduction of usermode networking, the network stack of podman machine on Windows uses port 2222 to forward ssh. This can conflict with the default of CRC which will ALWAYS use usermode networking and the 2222 port forward for ssh.

Steps to reproduce the issue

n/a

Describe the results you received

Unable to start either depending who comes first

Describe the results you expected

We should both be checking if the port is already in use and suggest an alternative.

podman info output

n/a

Podman in a container

No

Privileged Or Rootless

None

Upstream Latest Release

Yes

Additional environment details

Windows with Podman machine on WSL2 and CRC

Additional information

Usermode networking

crc-org/crc#3855

[gbraad]

@n1hility
We should both be checking if the port is already in use and suggest an alternative. Though, we might wanna solve this in gvproxy... as multiple instances of a WLS2 machine might run into the same issue.

https://github.com/containers/gvisor-tap-vsock/blob/2a3419da952638147a42db9d49bd74bd10d2340c/pkg/types/gvproxy_command.go#L35

There is re-assignment code, but this might be used more generically: 63a8926

[github-actions]

A friendly reminder that this issue had no activity for 30 days.

[rhatdan]

@gbraad @n1hility any movement on this one?

[n1hility]

I think I should fix this / work around on the wsl side. We can pick an unused port. It’s not actually used in this particular use case.

[github-actions]

A friendly reminder that this issue had no activity for 30 days.

[Luap99]

@n1hility Was this fixed with the port re-assign logic in machine?

[cfergeau]

The generic vmconfigs code in podman 5 seems to always allocate a random port and to never use 2222 :

podman/pkg/machine/vmconfigs/machine.go

Lines 85 to 95 in bb6b2e9

	sshPort, err := ports.AllocateMachinePort()
	if err != nil {
	return nil, err
	}
	sshConfig := SSHConfig{
	IdentityPath: sshIdentityPath,
	Port: sshPort,
	RemoteUsername: opts.Username,
	}