Fix docker ignore

Sources/ContainerBuild/Builder.swift

@@ -241,6 +241,7 @@ public struct Builder: Sendable {
         public let buildArgs: [String]
         public let contextDir: String
         public let dockerfile: Data
+        public let hiddenDockerDir: String?
         public let labels: [String]
         public let noCache: Bool
         public let platforms: [Platform]
@@ -259,6 +260,7 @@ public struct Builder: Sendable {
             buildArgs: [String],
             contextDir: String,
             dockerfile: Data,
+            hiddenDockerDir: String?,
             labels: [String],
             noCache: Bool,
             platforms: [Platform],
@@ -276,6 +278,7 @@ public struct Builder: Sendable {
             self.buildArgs = buildArgs
             self.contextDir = contextDir
             self.dockerfile = dockerfile
+            self.hiddenDockerDir = hiddenDockerDir
             self.labels = labels
             self.noCache = noCache
             self.platforms = platforms
@@ -319,6 +322,9 @@ extension CallOptions {
             ("progress", config.terminal != nil ? "tty" : "plain"),
             ("target", config.target),
         ]
+        if let hiddenDockerDir = config.hiddenDockerDir {
+            headers.append(("hidden-docker-dir", hiddenDockerDir))
+        }
         for tag in config.tags {
             headers.append(("tag", tag))
         }

Sources/ContainerCommands/BuildCommand.swift

@@ -28,6 +28,8 @@ import TerminalProgress
 
 extension Application {
     public struct BuildCommand: AsyncLoggableCommand {
+        private static let hiddenDockerDir = ".com.apple.container.dockerfiles"
+
         public init() {}
         public static var configuration: CommandConfiguration {
             var config = CommandConfiguration()
@@ -72,6 +74,8 @@ extension Application {
         @Option(name: .shortAndLong, help: ArgumentHelp("Path to Dockerfile", valueName: "path"))
         var file: String?
 
+        var dockerfile: String = "-"
+
         @Option(name: .shortAndLong, help: ArgumentHelp("Set a label", valueName: "key=val"))
         var label: [String] = []
 
@@ -204,24 +208,11 @@ extension Application {
                     throw ValidationError("builder is not running")
                 }
 
-                let buildFilePath: String
-                if let file = self.file {
-                    buildFilePath = file
-                } else {
-                    guard
-                        let resolvedPath = try BuildFile.resolvePath(
-                            contextDir: self.contextDir,
-                            log: log
-                        )
-                    else {
-                        throw ValidationError("failed to find Dockerfile or Containerfile in the context directory \(self.contextDir)")
-                    }
-                    buildFilePath = resolvedPath
-                }
-
                 let buildFileData: Data
+                var ignoreFileData: Data? = nil
+                var hiddenDockerDir: String? = nil
                 // Dockerfile should be read from stdin
-                if file == "-" {
+                if dockerfile == "-" {
                     let tempFile = FileManager.default.temporaryDirectory.appendingPathComponent("Dockerfile-\(UUID().uuidString)")
                     defer {
                         try? FileManager.default.removeItem(at: tempFile)
@@ -244,7 +235,27 @@ extension Application {
                     try fileHandle.close()
                     buildFileData = try Data(contentsOf: URL(filePath: tempFile.path()))
                 } else {
-                    buildFileData = try Data(contentsOf: URL(filePath: buildFilePath))
+                    let ignoreFileURL = URL(filePath: dockerfile + ".dockerignore")
+                    buildFileData = try Data(contentsOf: URL(filePath: dockerfile))
+                    ignoreFileData = try? Data(contentsOf: ignoreFileURL)
+
+                    if var ignoreFileData {
+                        hiddenDockerDir = Self.hiddenDockerDir
+                        let hiddenDirInContext = URL(fileURLWithPath: contextDir).appendingPathComponent(Self.hiddenDockerDir)
+
+                        try FileManager.default.createDirectory(at: hiddenDirInContext, withIntermediateDirectories: true)
+                        try buildFileData.write(to: hiddenDirInContext.appendingPathComponent("Dockerfile"))
+
+                        ignoreFileData.append("\n\(Self.hiddenDockerDir)".data(using: .utf8) ?? Data())
+                        try ignoreFileData.write(to: hiddenDirInContext.appendingPathComponent("Dockerfile.dockerignore"))
+                    }
+                }
+
+                defer {
+                    if let hiddenDockerDir {
+                        let hiddenDirInContext = URL(fileURLWithPath: contextDir).appendingPathComponent(hiddenDockerDir)
+                        try? FileManager.default.removeItem(at: hiddenDirInContext)
+                    }
                 }
 
                 let systemHealth = try await ClientHealthCheck.ping(timeout: .seconds(10))
@@ -316,13 +327,14 @@ extension Application {
                         }
                         return results
                     }()
-                    group.addTask { [terminal, buildArg, contextDir, label, noCache, target, quiet, cacheIn, cacheOut, pull] in
+                    group.addTask { [terminal, buildArg, contextDir, hiddenDockerDir, label, noCache, target, quiet, cacheIn, cacheOut, pull] in
                         let config = Builder.BuildConfig(
                             buildID: buildID,
                             contentStore: RemoteContentStoreClient(),
                             buildArgs: buildArg,
                             contextDir: contextDir,
                             dockerfile: buildFileData,
+                            hiddenDockerDir: hiddenDockerDir,
                             labels: label,
                             noCache: noCache,
                             platforms: [Platform](platforms),
@@ -412,8 +424,8 @@ extension Application {
             }
         }
 
-        public func validate() throws {
-            // NOTE: We'll "validate" the Dockerfile later.
+        public mutating func validate() throws {
+            // NOTE: Here we check the Dockerfile exists, and set `dockerfile` to point the valid Dockerfile path or stdin
             guard FileManager.default.fileExists(atPath: contextDir) else {
                 throw ValidationError("context dir does not exist \(contextDir)")
             }
@@ -422,6 +434,31 @@ extension Application {
                     throw ValidationError("invalid reference \(name)")
                 }
             }
+
+            switch file {
+            case "-":
+                dockerfile = "-"
+                break
+            case .some(let filepath):
+                let fileURL = URL(fileURLWithPath: filepath, relativeTo: .currentDirectory())
+                guard FileManager.default.fileExists(atPath: fileURL.path) else {
+                    throw ValidationError("dockerfile does not exist \(filepath)")
+                }
+
+                dockerfile = fileURL.path
+                break
+            case .none:
+                guard let defaultDockerfile = try BuildFile.resolvePath(contextDir: contextDir) else {
+                    throw ValidationError("dockerfile not found in context dir")
+                }
+
+                guard FileManager.default.fileExists(atPath: defaultDockerfile) else {
+                    throw ValidationError("dockerfile does not exist \(defaultDockerfile)")
+                }
+
+                dockerfile = defaultDockerfile
+                break
+            }
         }
     }
 }