Add SignImagesCommand to ImageBuilder (#1957)

Related:
- dotnet/dotnet-docker#4589
- #1376

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: lbussell

src/Dockerfile.linux

@@ -16,11 +16,13 @@ RUN dotnet restore -r linux-$TARGETARCH ./ImageBuilder/Microsoft.DotNet.ImageBui
 
 # copy everything else and publish
 COPY . ./
-RUN dotnet publish -r linux-$TARGETARCH ./ImageBuilder/Microsoft.DotNet.ImageBuilder.csproj --self-contained=true --no-restore -o out
+# MicroBuild signing requires running a DLL directly, so it is more size-efficient for ImageBuilder
+# to use the same runtime and ship as framework-dependent instead of self-contained.
+RUN dotnet publish -r linux-$TARGETARCH ./ImageBuilder/Microsoft.DotNet.ImageBuilder.csproj --no-restore -o out
 
 
 # build runtime image
-FROM mcr.microsoft.com/dotnet/runtime-deps:9.0-azurelinux3.0
+FROM mcr.microsoft.com/dotnet/runtime:9.0-azurelinux3.0
 
 # install tooling
 RUN tdnf install -y \

src/ImageBuilder.Tests/BuildCommandTests.cs

@@ -3533,8 +3533,7 @@ private static BuildCommand CreateBuildCommand(
             IManifestServiceFactory? manifestServiceFactory = null,
             IRegistryCredentialsProvider? registryCredentialsProvider = null,
             IAzureTokenCredentialProvider? azureTokenCredentialProvider = null,
-            IImageCacheService? imageCacheService = null,
-            IOptions<PublishConfiguration>? publishOptions = null)
+            IImageCacheService? imageCacheService = null)
         {
             BuildCommand command = new(
                 dockerService ?? Mock.Of<IDockerService>(),
@@ -3545,8 +3544,7 @@ private static BuildCommand CreateBuildCommand(
                 manifestServiceFactory ?? Mock.Of<IManifestServiceFactory>(),
                 registryCredentialsProvider ?? Mock.Of<IRegistryCredentialsProvider>(),
                 azureTokenCredentialProvider ?? Mock.Of<IAzureTokenCredentialProvider>(),
-                imageCacheService ?? Mock.Of<IImageCacheService>(),
-                publishOptions ?? CreateOptionsMock<PublishConfiguration>());
+                imageCacheService ?? Mock.Of<IImageCacheService>());
 
             return command;
         }

src/ImageBuilder.Tests/GenerateSigningPayloadsCommandTests.cs

@@ -0,0 +1,106 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.DotNet.ImageBuilder.Tests.Helpers;
+
+/// <summary>
+/// In-memory <see cref="IFileSystem"/> implementation for unit tests.
+/// Stores file contents in a dictionary and tracks all operations for assertions.
+/// </summary>
+internal sealed class InMemoryFileSystem : IFileSystem
+{
+    private readonly Dictionary<string, byte[]> _files = [];
+    private readonly HashSet<string> _directories = [];
+
+    /// <summary>
+    /// Paths written via <see cref="WriteAllText"/> or <see cref="WriteAllTextAsync"/>.
+    /// </summary>
+    public List<string> FilesWritten { get; } = [];
+
+    /// <summary>
+    /// Paths read via <see cref="ReadAllBytes"/>, <see cref="ReadAllBytesAsync"/>, or <see cref="ReadAllTextAsync"/>.
+    /// </summary>
+    public List<string> FilesRead { get; } = [];
+
+    /// <summary>
+    /// Paths deleted via <see cref="DeleteFile"/>.
+    /// </summary>
+    public List<string> FilesDeleted { get; } = [];
+
+    /// <summary>
+    /// Paths created via <see cref="CreateDirectory"/>.
+    /// </summary>
+    public List<string> DirectoriesCreated { get; } = [];
+
+    /// <summary>
+    /// Seeds a file with text content before a test runs.
+    /// </summary>
+    public void AddFile(string path, string contents) =>
+        _files[path] = Encoding.UTF8.GetBytes(contents);
+
+    /// <summary>
+    /// Seeds a file with binary content before a test runs.
+    /// </summary>
+    public void AddFile(string path, byte[] contents) =>
+        _files[path] = contents;
+
+    public void WriteAllText(string path, string contents)
+    {
+        _files[path] = Encoding.UTF8.GetBytes(contents);
+        FilesWritten.Add(path);
+    }
+
+    public Task WriteAllTextAsync(string path, string? contents, CancellationToken cancellationToken = default)
+    {
+        _files[path] = Encoding.UTF8.GetBytes(contents ?? string.Empty);
+        FilesWritten.Add(path);
+        return Task.CompletedTask;
+    }
+
+    public byte[] ReadAllBytes(string path)
+    {
+        FilesRead.Add(path);
+        return _files.TryGetValue(path, out var bytes)
+            ? bytes
+            : throw new FileNotFoundException("File not found", path);
+    }
+
+    public Task<byte[]> ReadAllBytesAsync(string path, CancellationToken cancellationToken = default) =>
+        Task.FromResult(ReadAllBytes(path));
+
+    public Task<string> ReadAllTextAsync(string path, CancellationToken cancellationToken = default)
+    {
+        FilesRead.Add(path);
+        return _files.TryGetValue(path, out var bytes)
+            ? Task.FromResult(Encoding.UTF8.GetString(bytes))
+            : throw new FileNotFoundException("File not found", path);
+    }
+
+    public bool FileExists(string path) => _files.ContainsKey(path);
+
+    public void DeleteFile(string path)
+    {
+        _files.Remove(path);
+        FilesDeleted.Add(path);
+    }
+
+    public DirectoryInfo CreateDirectory(string path)
+    {
+        _directories.Add(path);
+        DirectoriesCreated.Add(path);
+        return new DirectoryInfo(path);
+    }
+
+    /// <summary>
+    /// Gets the text content of a file, for test assertions.
+    /// </summary>
+    public string GetFileText(string path) =>
+        Encoding.UTF8.GetString(_files[path]);
+}