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

Leaving this here to save someone...

As I had docker configured on my wsl I got 2 ip addresses (check them by running ip addr in your wsl terminal)
found after line 9 run $wsl_ip = $(wsl hostname -I).Trim();.

After command execution log from line 19 looked like this: WSL IP: '172.19.222.216 172.17.0.1' , which prevented script from working properly and my phone connecting successfully to my windows ip.

After running ip addr and checking that my wsl ip is in fact 172.19.222.216,
fix was to simply change line 9 from $wsl_ip = $(wsl hostname -I).Trim(); to $wsl_ip = $(wsl hostname -I).Trim().Split(' ')[0];.