.net core - How to properly kill started process?

Question

I have a dotnet core 2.0 console app that starts up another dotnet core WebAPI. The problem is, how do I cleanly kill the WebAPI process when the console app is closed? Because as of now, I can't start the process twice since it gives an error the address is in use, and I can still see the process in the task manager.

Here is how I tried to do that but seems like it's missing something to completely kill all the processes:

class Program
{
    static Process cmd;

    static async Task Main(string[] args)
    {
        AppDomain.CurrentDomain.ProcessExit += CurrentDomain_ProcessExit;

        var startInfo = new ProcessStartInfo("cmd.exe")
        {
            UseShellExecute = false,
            RedirectStandardInput = true,
            CreateNoWindow = true,
        };

        cmd = new Process { StartInfo = startInfo };

        cmd.Start();

        using (cmd)
        {
            cmd.StandardInput.WriteLine($"cd C:/Project/publish");
            cmd.StandardInput.WriteLine($"dotnet WebAPI.dll");
            cmd.WaitForExit();
        }
    }

    static void CurrentDomain_ProcessExit(object sender, EventArgs e)
    {
        Process.GetProcessById(cmd.Id).Kill();
        Environment.Exit(0);
    }
}

Answer 1

As suggested by @mjwills I've updated the process as follows:

class Program
{
    static Process webAPI;

    static async Task Main(string[] args)
    {
        AppDomain.CurrentDomain.ProcessExit += CurrentDomain_ProcessExit;

        webAPI = new Process
        {
            StartInfo = new ProcessStartInfo("dotnet")
            {
                UseShellExecute = false,
                WorkingDirectory = "C:/Project/publish",
                Arguments = "WebAPI.dll",
                CreateNoWindow = true
            }
        };
        using (webAPI)
        {
            webAPI.Start();
            webAPI.WaitForExit();
        }
    }

    static void CurrentDomain_ProcessExit(object sender, EventArgs e)
    {
        webAPI.Close();
    }
}