Add alpine source build CI leg

src/SourceBuild/content/test/Microsoft.DotNet.SourceBuild.SmokeTests/DotNetHelper.cs

@@ -36,7 +36,7 @@ public DotNetHelper(ITestOutputHelper outputHelper)
                 }
 
                 Directory.CreateDirectory(Config.DotNetDirectory);
-                ExecuteHelper.ExecuteProcessValidateExitCode("tar", $"xzf {Config.SdkTarballPath} -C {Config.DotNetDirectory}", outputHelper);
+                Utilities.ExtractTarball(Config.SdkTarballPath, Config.DotNetDirectory);
             }
             IsMonoRuntime = DetermineIsMonoRuntime(Config.DotNetDirectory);
 

src/SourceBuild/content/test/Microsoft.DotNet.SourceBuild.SmokeTests/OmniSharpTests.cs

@@ -65,7 +65,7 @@ private async Task InitializeOmniSharp()
             await client.DownloadFileAsync(omniSharpTarballUrl, omniSharpTarballFile, OutputHelper);
 
             Directory.CreateDirectory(OmniSharpDirectory);
-            ExecuteHelper.ExecuteProcessValidateExitCode("tar", $"xzf {omniSharpTarballFile} -C {OmniSharpDirectory}", OutputHelper);
+            Utilities.ExtractTarball(omniSharpTarballFile, OmniSharpDirectory);
         }
     }
 }

src/SourceBuild/content/test/Microsoft.DotNet.SourceBuild.SmokeTests/SdkContentTests.cs

@@ -43,7 +43,7 @@ private void WriteTarballFileList(string? tarballPath, string outputFileName, bo
             throw new InvalidOperationException($"Tarball path '{tarballPath}' does not exist.");
         }
 
-        string fileListing = ExecuteHelper.ExecuteProcessValidateExitCode("tar", $"tf {tarballPath}", OutputHelper);
+        string fileListing = Utilities.GetTarballContentNames(tarballPath).Aggregate((a, b) => $"{a}{Environment.NewLine}{b}");
         fileListing = BaselineHelper.RemoveRids(fileListing, isPortable);
         fileListing = BaselineHelper.RemoveVersions(fileListing);
         IEnumerable<string> files = fileListing.Split(Environment.NewLine).OrderBy(path => path);

src/SourceBuild/content/test/Microsoft.DotNet.SourceBuild.SmokeTests/SourceBuiltArtifactsTests.cs

@@ -26,7 +26,7 @@ public void VerifyVersionFile()
         try
         {
             // Extract the .version file
-            Utilities.ExtractFileFromTarball(Config.SourceBuiltArtifactsPath, ".version", outputDir);
+            Utilities.ExtractTarball(Config.SourceBuiltArtifactsPath, outputDir, ".version");
 
             string[] versionLines = File.ReadAllLines(Path.Combine(outputDir, ".version"));
             Assert.Equal(2, versionLines.Length);
@@ -52,7 +52,7 @@ public void VerifyVersionFile()
             string sdkVersion = versionLines[1];
 
             // Find the expected SDK version by getting it from the SDK tarball
-            Utilities.ExtractFileFromTarball(Config.SdkTarballPath ?? string.Empty, "./sdk/*/.version", outputDir);
+            Utilities.ExtractTarball(Config.SdkTarballPath ?? string.Empty, outputDir, "./sdk/*/.version");
             DirectoryInfo sdkDir = new DirectoryInfo(Path.Combine(outputDir, "sdk"));
             string sdkVersionPath = sdkDir.GetFiles(".version", SearchOption.AllDirectories).Single().FullName;
             string[] sdkVersionLines = File.ReadAllLines(Path.Combine(outputDir, sdkVersionPath));

src/SourceBuild/content/test/Microsoft.DotNet.SourceBuild.SmokeTests/Utilities.cs

@@ -4,6 +4,7 @@
 
 using Microsoft.Extensions.FileSystemGlobbing;
 using System;
+using System.Collections.Generic;
 using System.Formats.Tar;
 using System.IO;
 using System.IO.Compression;
@@ -15,7 +16,14 @@ namespace Microsoft.DotNet.SourceBuild.SmokeTests;
 
 public static class Utilities
 {
-    public static void ExtractFileFromTarball(string tarballPath, string filePath, string outputDir)
+    public static void ExtractTarball(string tarballPath, string outputDir)
+    {
+        using FileStream fileStream = File.OpenRead(tarballPath);
+        using GZipStream decompressorStream = new(fileStream, CompressionMode.Decompress);
+        TarFile.ExtractToDirectory(decompressorStream, outputDir, true);
+    }
+
+    public static void ExtractTarball(string tarballPath, string outputDir, string filePath)
     {
         Matcher matcher = new();
         matcher.AddInclude(filePath);
@@ -39,6 +47,19 @@ public static void ExtractFileFromTarball(string tarballPath, string filePath, s
         }
     }
 
+    public static IEnumerable<string> GetTarballContentNames(string tarballPath)
+    {
+        using FileStream fileStream = File.OpenRead(tarballPath);
+        using GZipStream decompressorStream = new(fileStream, CompressionMode.Decompress);
+        using TarReader reader = new(decompressorStream);
+
+        TarEntry entry;
+        while ((entry = reader.GetNextEntry()) is not null)
+        {
+            yield return entry.Name;
+        }
+    }
+
     public static async Task RetryAsync(Func<Task> executor, ITestOutputHelper outputHelper)
     {
         await Utilities.RetryAsync(