Add host.docker.internal and gateway.docker.internal to hostentries using Entrypoint in Containers in Sitecore

hostentry.ps1

# Path to the system hosts file
$hostsFile = "C:\Windows\System32\drivers\etc\hosts"

try {
    # List of Docker special DNS names used to refer to the host
    $DnsEntries = @("host.docker.internal", "gateway.docker.internal")

    # Attempt to resolve each DNS entry
    foreach ($Entry in $DnsEntries) {
        Resolve-DnsName -Name $Entry -ErrorAction Stop  # Throws error if resolution fails
    }

    # If no exception was thrown, DNS is properly configured
    Write-Host("DNS settings are already configured.")
}
catch {
    # If DNS resolution fails, retrieve the host (gateway) IP from ipconfig output
    $ip = (ipconfig | where-object {$_ -match "Default Gateway"} | foreach-object{$_.Split(":")[1]}).Trim()

    # Read current lines from the hosts file
    $src = [System.IO.File]::ReadAllLines($hostsFile)

    # Create a modifiable copy of the lines with an extra line at the end
    $lines = $src += ""

    # Check if the hosts file already contains both entries
    if ((cat $hostsFile | Select-String -Pattern "host.docker.internal") -And (cat $hostsFile | Select-String -Pattern "gateway.docker.internal")) {
        # Update existing entries with the current host IP
        For ($i = 0; $i -le $lines.length; $i++) {
            if ($lines[$i].Contains("host.docker.internal")) {
                $lines[$i] = ("{0} host.docker.internal" -f $ip)
                $lines[$i+1] = ("{0} gateway.docker.internal" -f $ip)
                break
            }
        }
    } else {
        # Append new entries if not already present
        $lines = $lines += "# Added by Docker for Windows"
        $lines = $lines += ("{0} host.docker.internal" -f $ip)
        $lines = $lines += ("{0} gateway.docker.internal" -f $ip)
        $lines = $lines += "# End of section"
    }

    # Write the updated hosts file content back to disk
    [System.IO.File]::WriteAllLines($hostsFile, [string[]]$lines)

    Write-Host("New DNS settings written successfully.")
}

# Launch LogMonitor (required by Sitecore container) and start IIS service inside the container
& "C:\LogMonitor\LogMonitor.exe" "powershell" "C:\Run-W3SVCService.ps1"