Copy local file to pod using tar (#962)

* Copy local file to pod using tar

* Update examples/cp/Cp.cs

Co-authored-by: Boshi Lian <farmer1992@gmail.com>

* File names as command line args, default encoding

* command line args

Co-authored-by: Boshi Lian <farmer1992@gmail.com>

examples/cp/Cp.cs

@@ -0,0 +1,126 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using k8s;
+using ICSharpCode.SharpZipLib.Tar;
+using System.Threading;
+using System.Linq;
+using System.Text;
+
+namespace cp
+{
+    internal class Cp
+    {
+        private static IKubernetes client;
+
+        private static async Task Main(string[] args)
+        {
+            var config = KubernetesClientConfiguration.BuildConfigFromConfigFile();
+            client = new Kubernetes(config);
+
+
+            var pods = client.CoreV1.ListNamespacedPod("default", null, null, null, $"job-name=upload-demo");
+            var pod = pods.Items.First();
+
+            await CopyFileToPodAsync(pod.Metadata.Name, "default", "upload-demo", args[0], $"home/{args[1]}");
+
+        }
+
+
+
+
+        private static void ValidatePathParameters(string sourcePath, string destinationPath)
+        {
+            if (string.IsNullOrWhiteSpace(sourcePath))
+            {
+                throw new ArgumentException($"{nameof(sourcePath)} cannot be null or whitespace");
+            }
+
+            if (string.IsNullOrWhiteSpace(destinationPath))
+            {
+                throw new ArgumentException($"{nameof(destinationPath)} cannot be null or whitespace");
+            }
+
+        }
+
+        public static async Task<int> CopyFileToPodAsync(string name, string @namespace, string container, string sourceFilePath, string destinationFilePath, CancellationToken cancellationToken = default(CancellationToken))
+        {
+            // All other parameters are being validated by MuxedStreamNamespacedPodExecAsync called by NamespacedPodExecAsync
+            ValidatePathParameters(sourceFilePath, destinationFilePath);
+
+            // The callback which processes the standard input, standard output and standard error of exec method
+            var handler = new ExecAsyncCallback(async (stdIn, stdOut, stdError) =>
+            {
+                var fileInfo = new FileInfo(destinationFilePath);
+                try
+                {
+                    using (var memoryStream = new MemoryStream())
+                    {
+                        using (var inputFileStream = File.OpenRead(sourceFilePath))
+                        using (var tarOutputStream = new TarOutputStream(memoryStream, Encoding.Default)) 
+                        {
+                            tarOutputStream.IsStreamOwner = false;
+
+                            var fileSize = inputFileStream.Length;
+                            var entry = TarEntry.CreateTarEntry(fileInfo.Name);
+
+                            entry.Size = fileSize;
+
+                            tarOutputStream.PutNextEntry(entry);
+                            await inputFileStream.CopyToAsync(tarOutputStream);
+                            tarOutputStream.CloseEntry();
+                        }
+
+                        memoryStream.Position = 0;
+
+                        const int bufferSize = 31 * 1024 * 1024; // must be lower than 32 * 1024 * 1024
+                        byte[] localBuffer = new byte[bufferSize];
+                        while (true)
+                        {
+                            int numRead = await memoryStream.ReadAsync(localBuffer, 0, localBuffer.Length);
+                            if (numRead <= 0)
+                            {
+                                break;
+                            }
+                            await stdIn.WriteAsync(localBuffer, 0, numRead);
+                        }
+                        await stdIn.FlushAsync();
+                    }
+
+                }
+                catch (Exception ex)
+                {
+                    throw new IOException($"Copy command failed: {ex.Message}");
+                }
+
+                using StreamReader streamReader = new StreamReader(stdError);
+                while (streamReader.EndOfStream == false)
+                {
+                    string error = await streamReader.ReadToEndAsync();
+                    throw new IOException($"Copy command failed: {error}");
+                }
+            });
+
+            string destinationFolder = GetFolderName(destinationFilePath);
+
+            return await client.NamespacedPodExecAsync(
+                name,
+                @namespace,
+                container,
+                new string[] { "sh", "-c", $"tar xmf - -C {destinationFolder}" },
+                false,
+                handler,
+                cancellationToken);
+        }
+
+
+        private static string GetFolderName(string filePath)
+        {
+            var folderName = Path.GetDirectoryName(filePath);
+
+            return string.IsNullOrEmpty(folderName) ? "." : folderName;
+        }
+
+
+    }
+}