Add support for copying existing files via WithContainerFiles API

src/Aspire.Hosting.Keycloak/KeycloakResourceBuilderExtensions.cs

@@ -18,7 +18,8 @@ public static class KeycloakResourceBuilderExtensions
     private const int DefaultContainerPort = 8080;
     private const int ManagementInterfaceContainerPort = 9000; // As per https://www.keycloak.org/server/management-interface
     private const string ManagementEndpointName = "management";
-    private const string RealmImportDirectory = "/opt/keycloak/data/import";
+
+    private const string KeycloakDataDirectory = "/opt/keycloak/data";
 
     /// <summary>
     /// Adds a Keycloak container to the application model.
@@ -161,18 +162,16 @@ public static IResourceBuilder<KeycloakResource> WithRealmImport(
 
         var importFullPath = Path.GetFullPath(import, builder.ApplicationBuilder.AppHostDirectory);
 
-        if (Directory.Exists(importFullPath))
-        {
-            return builder.WithBindMount(importFullPath, RealmImportDirectory, isReadOnly);
-        }
-
-        if (File.Exists(importFullPath))
-        {
-            var fileName = Path.GetFileName(import);
-
-            return builder.WithBindMount(importFullPath, $"{RealmImportDirectory}/{fileName}", isReadOnly);
-        }
-
-        throw new InvalidOperationException($"The realm import file or directory '{importFullPath}' does not exist.");
+        return builder.WithContainerFiles(
+            KeycloakDataDirectory,
+            [
+                // The import directory may not exist by default, so we need to ensure it is created.
+                new ContainerDirectory
+                {
+                    Name = "import",
+                    // Import the file (or children if a directory) into the container.
+                    Entries = ContainerDirectory.GetFileSystemItemsFromPath(importFullPath),
+                },
+            ]);
     }
 }

src/Aspire.Hosting.PostgreSQL/PostgresBuilderExtensions.cs

@@ -400,7 +400,13 @@ public static IResourceBuilder<PostgresServerResource> WithInitBindMount(this IR
         ArgumentNullException.ThrowIfNull(builder);
         ArgumentException.ThrowIfNullOrEmpty(source);
 
-        return builder.WithBindMount(source, "/docker-entrypoint-initdb.d", isReadOnly);
+        const string initPath = "/docker-entrypoint-initdb.d";
+
+        var importFullPath = Path.GetFullPath(source, builder.ApplicationBuilder.AppHostDirectory);
+
+        return builder.WithContainerFiles(
+            initPath,
+            ContainerDirectory.GetFileSystemItemsFromPath(importFullPath));
     }
 
     /// <summary>

src/Aspire.Hosting/ApplicationModel/ContainerFileSystemCallbackAnnotation.cs

@@ -24,7 +24,7 @@ public string Name
 
             if (Path.GetDirectoryName(value) != string.Empty)
             {
-                throw new ArgumentException("Name must be a simple file or folder name and not include any path separators (eg, / or \\). To specify parent folders, use one or more ContainerDirectory entries.", nameof(value));
+                throw new ArgumentException($"Name '{value}' must be a simple file or folder name and not include any path separators (eg, / or \\). To specify parent folders, use one or more ContainerDirectory entries.", nameof(value));
             }
 
             _name = value;
@@ -52,10 +52,17 @@ public string Name
 /// </summary>
 public sealed class ContainerFile : ContainerFileSystemItem
 {
+
     /// <summary>
-    /// The contents of the file. If null, the file will be created as an empty file.
+    /// The contents of the file. Setting Contents is mutually exclusive with <see cref="SourcePath"/>. If both are set, an exception will be thrown.
     /// </summary>
     public string? Contents { get; set; }
+
+    /// <summary>
+    /// The path to a file on the host system to copy into the container. This path must be absolute and point to a file on the host system.
+    /// Setting SourcePath is mutually exclusive with <see cref="Contents"/>. If both are set, an exception will be thrown.
+    /// </summary>
+    public string? SourcePath { get; set; }
 }
 
 /// <summary>
@@ -67,6 +74,110 @@ public sealed class ContainerDirectory : ContainerFileSystemItem
     /// The contents of the directory to create in the container. Will create specified <see cref="ContainerFile"/> and <see cref="ContainerDirectory"/> entries in the directory.
     /// </summary>
     public IEnumerable<ContainerFileSystemItem> Entries { get; set; } = [];
+
+    private class FileTree : Dictionary<string, FileTree>
+    {
+        public required ContainerFileSystemItem Value { get; set; }
+
+        public static IEnumerable<ContainerFileSystemItem> GetItems(KeyValuePair<string, FileTree> node)
+        {
+            return node.Value.Value switch
+            {
+                ContainerDirectory dir => [
+                    new ContainerDirectory
+                    {
+                        Name = dir.Name,
+                        Entries = node.Value.SelectMany(GetItems),
+                    },
+                ],
+                ContainerFile file => [file],
+                _ => throw new InvalidOperationException($"Unknown file system item type: {node.Value.GetType().Name}"),
+            };
+        }
+    }
+
+    /// <summary>
+    /// Enumerates files from a specified directory and converts them to <see cref="ContainerFile"/> objects.
+    /// </summary>
+    /// <param name="path">The directory path to enumerate files from.</param>
+    /// <param name="searchPattern"></param>
+    /// <param name="searchOptions"></param>
+    /// <returns>
+    /// An enumerable collection of <see cref="ContainerFileSystemItem"/> objects.
+    /// </returns>
+    /// <exception cref="DirectoryNotFoundException">Thrown when the specified path does not exist.</exception>
+    public static IEnumerable<ContainerFileSystemItem> GetFileSystemItemsFromPath(string path, string searchPattern = "*", SearchOption searchOptions = SearchOption.TopDirectoryOnly)
+    {
+        var fullPath = Path.GetFullPath(path);
+
+        if (Directory.Exists(fullPath))
+        {
+            // Build a tree of the directories and files found
+            FileTree root = new FileTree
+            {
+                Value = new ContainerDirectory
+                {
+                    Name = "root",
+                }
+            };
+
+            foreach (var file in Directory.GetFiles(path, searchPattern, searchOptions).Order(StringComparer.Ordinal))
+            {
+                var relativePath = file.Substring(fullPath.Length + 1);
+                var fileName = Path.GetFileName(relativePath);
+                var parts = relativePath.Split([Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar], StringSplitOptions.RemoveEmptyEntries);
+                var node = root;
+                foreach (var part in parts.SkipLast(1))
+                {
+                    if (node.TryGetValue(part, out var childNode))
+                    {
+                        node = childNode;
+                    }
+                    else
+                    {
+                        var newNode = new FileTree
+                        {
+                            Value = new ContainerDirectory
+                            {
+                                Name = part,
+                            }
+                        };
+                        node.Add(part, newNode);
+                        node = newNode;
+                    }
+                }
+
+                node.Add(fileName, new FileTree
+                {
+                    Value = new ContainerFile
+                    {
+                        Name = fileName,
+                        SourcePath = file,
+                    }
+                });
+            }
+
+            return root.SelectMany(FileTree.GetItems);
+        }
+
+        if (File.Exists(fullPath))
+        {
+            if (searchPattern != "*")
+            {
+                throw new ArgumentException($"A search pattern was specified, but the given path '{fullPath}' is a file. Search patterns are only valid for directories.", nameof(searchPattern));
+            }
+
+            return [
+                new ContainerFile
+                {
+                    Name = Path.GetFileName(fullPath),
+                    SourcePath = fullPath,
+                }
+            ];
+        }
+
+        throw new InvalidOperationException($"The specified path '{fullPath}' does not exist.");
+    }
 }
 
 /// <summary>

src/Aspire.Hosting/Dcp/Model/Container.cs

@@ -348,7 +348,13 @@ public static ContainerFileSystemEntry ToContainerFileSystemEntry(this Container
 
         if (item is ContainerFile file)
         {
+            entry.Source = file.SourcePath;
             entry.Contents = file.Contents;
+
+            if (file.Contents is not null && file.SourcePath is not null)
+            {
+                throw new ArgumentException("Both SourcePath and Contents are set for a file entry");
+            }
         }
         else if (item is ContainerDirectory directory)
         {
@@ -381,7 +387,11 @@ internal sealed class ContainerFileSystemEntry : IEquatable<ContainerFileSystemE
     [JsonPropertyName("mode")]
     public int Mode { get; set; }
 
-    // If the file system entry is a file, this is the contents of that file. Setting Contents for a directory is an error.
+    // If the file system entry is a file, this is the optional path to a file on the host to use as the contents of that file.
+    [JsonPropertyName("source")]
+    public string? Source { get; set; }
+
+    // If the file system entry is a file, this is the contents of that file. Setting Contents for a directory is an error. Contents and Source are mutually exclusive.
     [JsonPropertyName("contents")]
     public string? Contents { get; set; }
 
@@ -401,6 +411,7 @@ public bool Equals(ContainerFileSystemEntry? other)
             && Owner == other.Owner
             && Group == other.Group
             && Mode == other.Mode
+            && Source == other.Source
             && Contents == other.Contents
             && (Entries ?? Enumerable.Empty<ContainerFileSystemEntry>()).SequenceEqual(other.Entries ?? Enumerable.Empty<ContainerFileSystemEntry>());
     }

tests/Aspire.Hosting.Keycloak.Tests/KeycloakPublicApiTests.cs

@@ -151,7 +151,7 @@ public void WithRealmImportShouldThrowWhenImportDoesNotExist()
     [InlineData(null)]
     [InlineData(true)]
     [InlineData(false)]
-    public void WithRealmImportDirectoryAddsBindMountAnnotation(bool? isReadOnly)
+    public async Task WithRealmImportDirectoryAddsContainerFilesAnnotation(bool? isReadOnly)
     {
         using var builder = TestDistributedApplicationBuilder.Create();
 
@@ -170,19 +170,24 @@ public void WithRealmImportDirectoryAddsBindMountAnnotation(bool? isReadOnly)
             keycloak.WithRealmImport(tempDirectory);
         }
 
-        var containerAnnotation = keycloak.Resource.Annotations.OfType<ContainerMountAnnotation>().Single();
+        using var app = builder.Build();
+        var keycloakResource = builder.Resources.Single(r => r.Name.Equals(resourceName, StringComparison.Ordinal));
 
-        Assert.Equal(tempDirectory, containerAnnotation.Source);
-        Assert.Equal("/opt/keycloak/data/import", containerAnnotation.Target);
-        Assert.Equal(ContainerMountType.BindMount, containerAnnotation.Type);
-        Assert.Equal(isReadOnly ?? false, containerAnnotation.IsReadOnly);
+        var containerAnnotation = keycloak.Resource.Annotations.OfType<ContainerFileSystemCallbackAnnotation>().Single();
+
+        var entries = await containerAnnotation.Callback(new() { Model = keycloakResource, ServiceProvider = app.Services }, CancellationToken.None);
+
+        Assert.Equal("/opt/keycloak/data", containerAnnotation.DestinationPath);
+        var importDirectory = Assert.IsType<ContainerDirectory>(entries.First());
+        Assert.Equal("import", importDirectory.Name);
+        Assert.Empty(importDirectory.Entries);
     }
 
     [Theory]
     [InlineData(null)]
     [InlineData(true)]
     [InlineData(false)]
-    public void WithRealmImportFileAddsBindMountAnnotation(bool? isReadOnly)
+    public async Task WithRealmImportFileAddsContainerFilesAnnotation(bool? isReadOnly)
     {
         using var builder = TestDistributedApplicationBuilder.Create();
 
@@ -205,11 +210,18 @@ public void WithRealmImportFileAddsBindMountAnnotation(bool? isReadOnly)
             keycloak.WithRealmImport(filePath);
         }
 
-        var containerAnnotation = keycloak.Resource.Annotations.OfType<ContainerMountAnnotation>().Single();
+        using var app = builder.Build();
+        var keycloakResource = builder.Resources.Single(r => r.Name.Equals(resourceName, StringComparison.Ordinal));
+
+        var containerAnnotation = keycloak.Resource.Annotations.OfType<ContainerFileSystemCallbackAnnotation>().Single();
+
+        var entries = await containerAnnotation.Callback(new() { Model = keycloakResource, ServiceProvider = app.Services }, CancellationToken.None);
 
-        Assert.Equal(filePath, containerAnnotation.Source);
-        Assert.Equal($"/opt/keycloak/data/import/{file}", containerAnnotation.Target);
-        Assert.Equal(ContainerMountType.BindMount, containerAnnotation.Type);
-        Assert.Equal(isReadOnly ?? false, containerAnnotation.IsReadOnly);
+        Assert.Equal("/opt/keycloak/data", containerAnnotation.DestinationPath);
+        var importDirectory = Assert.IsType<ContainerDirectory>(entries.First());
+        Assert.Equal("import", importDirectory.Name);
+        var realmFile = Assert.IsType<ContainerFile>(Assert.Single(importDirectory.Entries));
+        Assert.Equal(file, realmFile.Name);
+        Assert.Equal(filePath, realmFile.SourcePath);
     }
 }

tests/Aspire.Hosting.PostgreSQL.Tests/PostgresFunctionalTests.cs

@@ -376,7 +376,8 @@ public async Task VerifyWithInitBindMount()
                 INSERT INTO "Cars" (brand) VALUES ('BatMobile');
                 """);
 
-            using var builder = TestDistributedApplicationBuilder.CreateWithTestContainerRegistry(testOutputHelper);
+            using var builder = TestDistributedApplicationBuilder
+                .CreateWithTestContainerRegistry(testOutputHelper);
 
             var postgresDbName = "db1";
             var postgres = builder.AddPostgres("pg").WithEnvironment("POSTGRES_DB", postgresDbName);

tests/Aspire.Hosting.Tests/DistributedApplicationTests.cs

@@ -449,6 +449,12 @@ public async Task VerifyContainerCreateFile()
                         Contents = "Hello World!",
                         Mode = UnixFileMode.UserRead | UnixFileMode.UserWrite,
                     },
+                    new ContainerFile
+                    {
+                        Name = "test2.sh",
+                        SourcePath = "/tmp/test2.sh",
+                        Mode = UnixFileMode.UserExecute | UnixFileMode.UserWrite | UnixFileMode.UserRead,
+                    },
                 ],
             },
         };