push-package.cs

using System;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

namespace MacPushTestApp
{
    class Program
    {
        static int Main(string[] args)
        {
            if (args.Length != 2 || !Guid.TryParse(args[0], out Guid _guid) || !File.Exists(args[1]))
            {
                Console.WriteLine("Usage: push-package APIKEY PACKAGEFILE");
                return 1;
            }

            string source = "https://www.nuget.org/api/v2/package";
            string apiKey = args[0];
            string packagePath = args[1];

            if (PushPackage(source, apiKey, packagePath).Result)
            {
                return 0;
            }

            return 2;
        }

        static async Task<bool> PushPackage(string source, string apiKey, string packagePath)
        {
            var request = WebRequest.CreateHttp(source);
            request.Method = "PUT";
            request.SendChunked = true;

            request.Headers.Add("X-NuGet-ApiKey", apiKey);
            request.Headers.Add("X-NuGet-Client-Version", "4.3.0");

            var content = new MultipartFormDataContent();
            var fileStream = new FileStream(packagePath, FileMode.Open, FileAccess.Read, FileShare.Read);
            var packageContent = new StreamContent(fileStream);
            packageContent.Headers.ContentType = MediaTypeHeaderValue.Parse("application/octet-stream");

            //"package" and "package.nupkg" are random names for content deserializing
            //not tied to actual package name.
            content.Add(packageContent, "package", "package.nupkg");

            request.ContentType = content.Headers.ContentType.ToString();
            request.ContentLength = content.Headers.ContentLength.Value;

            Stream requestStream = request.GetRequestStream();
            var data = await content.ReadAsByteArrayAsync();
            await requestStream.WriteAsync(data, 0, data.Length);

            var response = (HttpWebResponse)await request.GetResponseAsync();

            if (response.StatusCode != HttpStatusCode.OK)
            {
                Console.WriteLine($"Failed with status code {response.StatusCode}");
                return false;
            }

            return true;
        }
    }
}