Add user-mode networking feature to Windows/WSL

[n1hility]

Certain VPN setups or other specialized networking configs will block traffic from the virtual WSL networking device, resulting in the podman WSL backend from being unable to contact systems on the VPN, and potentially losing internet access altogether. While some VPN providers provide configuration options to allow traffic from VMs, users may be prevented by policy from changing these options, or they may require networking infrastructure changes that require time to implement.

This PR adds a user-mode networking capability to podman machine on Windows, that works around this issue by rerouting all traffic over a user-space process running on the host, similar to the setup in use on Linux and Mac.

It adds a --user-mode-networking flag to podman machine init and podman machine set to configure the specified machine instance for user-mode networking.

When specified, init will provision an additional WSL distribution for dynamically configuring and running the user-mode networking environment. The user-mode network dist replaces the WSL network configuration with a tap device that is tunneled to a gvproxy.exe process running on the host (using the stdio transport, which was recently contributed to gvisor-tap-vsock by the wsl-vpnkit author). All traffic from all running WSL distributions (including DNS) is rerouted over this process. podman machine start launches this special dist along with any machine instance configured to require it. The usage of the user-mode env dist is reference counted with cooperative file-locking: subsequent machine starts will share the same instance, and the last user-mode-net requiring machine will stop the networking dist, restoring the standard WSL network as part of its shutdown.

Machine instances that do not require user-mode networking will still participate in the user-mode network when running (required since the kernel is shared across all WSL dists), but they will not prevent the user-mode network from closing. Instead, traffic will begin to flow over the standard WSL network setup.

Since the qemu backend on Linux and Mac are designed around user-mode networking, this option is restricted to always be true on those platforms.

This PR also includes a commit to address an unrelated win installer CI failure that was showing up in the verification of this PR (an environment-varying go build issue can be triggered where it over-eagerly builds unnessecary transitive deps, including gpgme that won't normally build cleanly on Windows)

A follow-up PR will add a section to the Windows tutorial.

Windows: Add a user-mode networking option to improve interop with VPN configs that drop traffic from WSL networking

[NO NEW TESTS NEEDED]

[openshift-ci]

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[n1hility]

PTAL @containers/podman-maintainers

(Also FYI @baude this updates the installer/zip bundled gvproxy version to the same version (0.6.1) that we have been testing with hyper-v)

[Luap99]

just some drive by comments, I have no way of actually reviewing/testing this.

[n1hility]

@Luap99 thanks for the feedback. I updated the PR to address your notes.

Ill keep an eye on the next test run, but shouldn't have an impact

[n1hility]

Looks like tests came back green on the updates to Paul's notes

PTAL @containers/podman-maintainers when you get a chance.

[baude]

LGTM

[rhatdan]

/lgtm

[Bharath-vi]

I getting this error after restarting my sysytem, do we need to add these file everytime ?

cp: cannot stat '/mnt/wsl/resolv.conf': No such file or directory
Error: error setting up user-mode networking: exit status 1

I have enabled user mode networking, got this error

PS C:\Users> podman machine start
Starting machine "podman-machine-default"
Starting user-mode networking...
cp: cannot stat '/mnt/wsl/resolv.conf': No such file or directory
Error: error setting up user-mode networking: exit status 1

then, i have added resolv.conf and wsl.conf
resolv.conf
nameserver 1.1.1.1
nameserver 8.8.8.8
wsl.conf
[network]
generateResolvConf = false