- Hypervisor (Vagrant Provider): Virtualbox
- Vagrant on Windows
The default networking mode of Vagrant is host-only network.
Network services (e.g, SSH's 22, HTTP's 80) can be accessed from WSL directly.
No need for port forwarding.
The command vagrant ssh-config shows misleading messages.
It shows the port as 2200 by default, but it means the 22 guest port is forwarded to the 2200 host port.
It also shows that password authentication is not allowed, but in fact I tried login in from WSL with password and it works.
Instead, /etc/ssh/sshd_config in the Vagrant machine shows that the default config is port 22 and allows password authentication.
The correct guest SSH port can be seen in the vagrant up messages.
==> default: Forwarding ports...
default: 22 (guest) => 2200 (host) (adapter 1)
The private key is not needed.
ssh 192.168.33.10 -l vagrant
The password is also vagrant.
Sometimes Vagrant gets stuck in the vagrant up or vagrant reload process.
The solution is to send an ACPI shutdown signal from Virtualbox GUI, though I don't know the reason.
ExpressVPN disrupts an already-running VM's networking. vagrant reload doesn't fixes it. The VM must be recreated to work under ExpressVPN.
It'd better to create the Vagrant VM after ExpressVPN.
Hyper-V's networking is not configurable by Vagrant, and its default network switch does not allow connection from WSL in the WSL Hyper-V switch.
Reference: https://www.vagrantup.com/docs/providers/hyperv/limitations
Vagrant in WSL still uses the hypervisor on the Windows host, so there is no practical advantage.
One nuisance is that Vagrant in WSL can only use Vagrantfile on the Windows host file system.
I haven't tried nested virtualization inside WSL yet, maybe I should give KVM a shot someday.