Forward WSL2 ports to host

forward_wsl2_ports.ps1

# Forward WSL2 ports to host machine/platform (handles Windows Firewall)
#
# NOTE: 'iex' is a shortform for 'Invoke-Expression'

# Ports that should be forwarded to WSL2 and allowed through firewall (comma-separated)
$ports = @(8081);

# WSL IP address changes whenever WSL restarts
$wsl_ip = $(wsl hostname -I).Trim();

# Incoming requests from any IP should be matched
$listen_all_ips = '0.0.0.0';

if ( -Not $wsl_ip ) {
  Write-Output "IP address for WSL 2 cannot be found";
  exit;
}

Write-Output "WSL IP: '$wsl_ip'";

### Windows Firewall #####

$firewall_rule = "WSL2 Forwarded Ports";
$firewall_ports = $ports -join ",";

# Remove existing firewal rule (will error if not already present; can ignore)
iex "Remove-NetFireWallRule -DisplayName '$firewall_rule' ";

# Allow Expo ports through Windows Firewall
iex "New-NetFireWallRule -DisplayName '$firewall_rule' -Direction Inbound -LocalPort $firewall_ports -Action Allow -Protocol TCP;"
iex "New-NetFireWallRule -DisplayName '$firewall_rule' -Direction Outbound -LocalPort $firewall_ports -Action Allow -Protocol TCP;"

### WSL Port Proxy #####

# Show all previously proxied ports
iex "netsh interface portproxy show v4tov4"

# Configure port forwarding (via remove/add)
for ( $i = 0; $i -lt $ports.length; $i++ ) {
  $port = $ports[$i];
  # Remove previously proxied port
  iex "netsh interface portproxy delete v4tov4 listenport=$port listenaddress=$listen_all_ips"
  iex "netsh interface portproxy add v4tov4 listenport=$port listenaddress=$listen_all_ips connectport=$port connectaddress=$wsl_ip"
}

# Show all newly proxied ports
iex "netsh interface portproxy show v4tov4"

cmd /c pause

An more thorough explanation can be found at GitHub - kendallroth/payme. One thing to note is that this is a powershell script intended to be run with administrator/elevated permissions 🤷. I'm not sure if the $windows_ip variable might need to be changed, but 0.0.0.0 allows all IP addresses instead of locking to a specific one 🤷. This script also works solely for Expo ports (would need to be changed otherwise), and should be complemented with a run script in the package.json.

Script has been updated to handle forwarding any WSL2 ports to the host/local (such as Expo, etc), with a bit more documentation and less hardcoded-variables.

Posting this to save someone, somewhere a little time....
If you're using nativewind 4.0.X you'll want to update the ports to something like$ports = @(8081,8089); . Basically anything else that has its own build server and needs fast-refresh you'll add those ports as well. Some tools are like this.

@kendallroth great powershell script btw. Thank you.

@the-simian Can you please post your edited script I am using nativewind 4.0.X too.

can we make the $post any port?

thanks in anticipation

@chrisgate just change line 6 in the original script to include more ports. You can include as many as you'd like, any port number. In the default case I changed
$ports = @(8081);
to
$ports = @(8081,8089);