Allow WSL2 to connect to SQL Server on Windows

sql_server_proxy.sh

#!/usr/bin/env bash

#
# This script proxies connections from localhost:1433 to
#  the dynamic WSL2 host IP
#
# Requirement:
#       Run sqlServerListenOnWSL2IP.ps1 to allow WSL2 to connect to SQL Server
#

uniqname="/tmp/sqlproxy-$(date +%s)"

# From Philipp Scheit (https://pscheit.medium.com/get-the-ip-address-of-the-desktop-windows-host-in-wsl2-7dc61653ad51)
wslhostip=$(ipconfig.exe | grep 'vEthernet (WSL)' -A4 | cut -d":" -f 2 | tail -n1 | sed -e 's/\s*//g')
echo "Windows host is at: $wslhostip..."

echo "
load_module /usr/lib/nginx/modules/ngx_stream_module.so;
daemon off;

events { }

stream {
        server {
                listen 1433;
                proxy_pass $wslhostip:1433;
        }
}
" > $uniqname

function cleanup() {
        rm $uniqname
        exit
}

trap cleanup INT

sudo nginx -c $uniqname

sqlServerListenOnWSL2IP.ps1

#
# This script configures SQL Server on Windows to listen for connections
#	from the network adapter connected to WSL2
#
# Assumptions:
#	1) There is only a single SQL Server instance
#	2) SQL Server should only listen for local and WSL2 connections
#	3) The network adapter connected to WSL2 has the phrase "(WSL)" in the name
#
# Requirement:
# 	1) Run the script as admin
#	2) Configure firewall to allow WSL2 to connect to Windows
#

##
# Imports
##

Import-Module sqlps

##
# Variables
##

# Fetch the ip address of the network adapter connected to WSL2
$wslNetIp = Get-NetIPAddress -AddressFamily IPv4 | Where-Object {$_.InterfaceAlias -like "*(WSL)*"} | Select -First 1

$smo = 'Microsoft.SqlServer.Management.Smo.'
$wmi = new-object ($smo + 'Wmi.ManagedComputer').

##
# Main
##

if ($wmi.ServerInstances.Count -eq 0) {
	Write-Output "No SQL Server instances found"
	exit
}

# Assumption: local machine only has a single SQL Server instance
$instance = $wmi.ServerInstances[0]
$tcp = $instance.ServerProtocols['Tcp']

# Enable Tcp/Ip protocol
if ($tcp.IsEnabled -ne $true) {
	$tcp.IsEnabled = $true
	$tcp.Alter()
}

$ipAddresses = $tcp.IPAddresses

Foreach ($ip in $ipAddresses) {
	$addr = $ip.IPAddress.IPAddressToString
	$props = $ip.IPAddressProperties

	if (
		$addr -eq "127.0.0.1" -or
		$addr -eq "::1"
	) {
		# Listen on localhost
		if ($props['Enabled'].Value -ne $true) {
			$props['Enabled'].Value = $true
			$tcp.Alter()
		}
	} else {
		# Disable on other IPs
		if ($props['Enabled'].Value -eq $true) {
			$props['Enabled'].Value = $false
			$tcp.Alter()
		}
	}
}

$wslIP = $ipAddresses | Where-Object {$_.IPAddress.IPAddressToString -eq $wslNetIp.IPAddress}
if ($wslIP -eq $null) {
	# Did not find an existing IP configuration, using the first non-local IP config
	$wslIP = $ipAddresses | 
		Where-Object {
			$_.IPAddress.IPAddressToString -ne "127.0.0.1" -and
			$_.IPAddress.IPAddressToString -ne "::1"
		} |
		Select -First 1

	$wslIP.IPAddressProperties['IpAddress'].Value = $wslNetIp.IPAddress
	$tcp.Alter()
}

# Listen for connections from WSL2
$wslIPStat = $wslIP.IPAddressProperties["Enabled"]
if ($wslIPStat.Value -ne $true) {
	$wslIPStat.Value = $true
	$tcp.Alter()
}

Write-Output "Restarting SQL Server..."
Restart-Service -Force MSSQLSERVER