Credentials: update Keychain entry if it already exists (#149)

* OCI: support Basic authentication scheme

* .isValid → .isValid()

* tart login: make --username optional

.cirrus.yml

@@ -1,14 +1,16 @@
-persistent_worker:
-  labels:
-    name: Mac-Mini-M1
-
 task:
-  name: Test
+  name: Test on Ventura
+  persistent_worker:
+    labels:
+      name: Mac-Mini-M1
+  build_script: swift test
   test_script: swift test
 
 task:
   name: Build
   only_if: $CIRRUS_TAG == ''
+  macos_instance:
+    image: ghcr.io/cirruslabs/macos-monterey-xcode:14
   build_script: swift build --product tart
   sign_script: codesign --sign - --entitlements Resources/tart.entitlements --force .build/debug/tart
   binary_artifacts:
@@ -17,7 +19,13 @@ task:
 task:
   name: Release
   only_if: $CIRRUS_TAG != ''
+  macos_instance:
+    image: ghcr.io/cirruslabs/macos-monterey-xcode:14
   env:
     GITHUB_TOKEN: ENCRYPTED[!98ace8259c6024da912c14d5a3c5c6aac186890a8d4819fad78f3e0c41a4e0cd3a2537dd6e91493952fb056fa434be7c!]
     GORELEASER_KEY: ENCRYPTED[!9b80b6ef684ceaf40edd4c7af93014ee156c8aba7e6e5795f41c482729887b5c31f36b651491d790f1f668670888d9fd!]
+  install_script: brew install go goreleaser/tap/goreleaser-pro
+  info_script:
+    - xcodebuild -version
+    - swift -version
   release_script: goreleaser

.goreleaser.yml

@@ -7,13 +7,13 @@ builds:
     goarch:
       - arm64
     prebuilt:
-      path: .build/{{ .Arch }}-apple-macosx/release/tart
+      path: .build/{{ .Arch }}-apple-macosx/debug/tart
 
 before:
   hooks:
     - .ci/set-version.sh
-    - swift build -c release --product tart
-    - codesign --sign - --entitlements Resources/tart.entitlements --force .build/arm64-apple-macosx/release/tart
+    - swift build -c debug --product tart
+    - codesign --sign - --entitlements Resources/tart.entitlements --force .build/arm64-apple-macosx/debug/tart
 
 archives:
   - id: binary
@@ -36,5 +36,7 @@ brews:
     homepage: https://github.com/cirruslabs/tart
     description: Run macOS VMs on Apple Silicon
     skip_upload: auto
+    dependencies:
+      - "cirruslabs/cli/softnet"
     custom_block: |
       depends_on :macos => :monterey

README.md

@@ -55,6 +55,31 @@ config from above will just work in Cirrus CI and your tasks will be executed in
 
 **Note:** Cirrus CI only allows [images managed and regularly updated by us](https://github.com/orgs/cirruslabs/packages?tab=packages&q=macos).
 
+### Retrieving artifacts from within Tart VMs
+
+In many cases there is a need to retrieve particular files or a folder from within a Tart virtual machine.
+For example, the below `.cirrus.yml` configuration defines a single task that builds a `tart` binary and
+exposes it via [`artifacts` instruction](https://cirrus-ci.org/guide/writing-tasks/#artifacts-instruction):
+
+```yaml
+task:
+  name: Build
+  macos_instance:
+    image: ghcr.io/cirruslabs/macos-monterey-xcode:latest
+  build_script: swift build --product tart
+  binary_artifacts:
+    path: .build/debug/tart
+```
+
+Running Cirrus CLI with `--artifacts-dir` will write defined `artifacts` to the provided local directory on the host:
+
+```bash
+cirrus run --artifacts-dir artifacts
+```
+
+Note that all retrieved artifacts will be prefixed with the associated task name and `artifacts` instruction name.
+For the example above, `tart` binary will be saved to `$PWD/artifacts/Build/binary/.build/debug/tart`.
+
 ## Virtual Machine Management
 
 ### Creating from scratch

Resources/AppIcon.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:8dd6af1a08bbcdc4faf0ff53601b38136c90231e11bd81bc8cd477d6f1c7d3f2
-size 209404
+oid sha256:1fe96aed7a965b075300f092a3ca76e09053eb7cf2f3125c3a819098a8bc4b31
+size 123360

Sources/tart/ARP/ARPCache.swift

@@ -1,119 +0,0 @@
-import Foundation
-import Network
-import Virtualization
-
-struct ARPCommandFailedError: Error, CustomStringConvertible {
-  var terminationReason: Process.TerminationReason
-  var terminationStatus: Int32
-
-  var description: String {
-    var reason: String
-
-    switch terminationReason {
-    case .exit:
-      reason = "exit code \(terminationStatus)"
-    case .uncaughtSignal:
-      reason = "uncaught signal"
-    default:
-      reason = "unknown reason"
-    }
-
-    return "arp command failed: \(reason)"
-  }
-}
-
-struct ARPCommandYieldedInvalidOutputError: Error, CustomStringConvertible {
-  var explanation: String
-
-  var description: String {
-    "arp command yielded invalid output: \(explanation)"
-  }
-}
-
-struct ARPCacheInternalError: Error, CustomStringConvertible {
-  var explanation: String
-
-  var description: String {
-    "ARPCache internal error: \(explanation)"
-  }
-}
-
-struct ARPCache {
-  static func ResolveMACAddress(macAddress: MACAddress, bridgeOnly: Bool = true) throws -> IPv4Address? {
-    let process = Process.init()
-    process.executableURL = URL.init(fileURLWithPath: "/usr/sbin/arp")
-    process.arguments = ["-an"]
-
-    let pipe = Pipe()
-    process.standardOutput = pipe
-    process.standardError = pipe
-    process.standardInput = FileHandle.nullDevice
-
-    try process.run()
-    process.waitUntilExit()
-
-    if !(process.terminationReason == .exit && process.terminationStatus == 0) {
-      throw ARPCommandFailedError(
-        terminationReason: process.terminationReason,
-        terminationStatus: process.terminationStatus)
-    }
-
-    guard let rawLines = try pipe.fileHandleForReading.readToEnd() else {
-      throw ARPCommandYieldedInvalidOutputError(explanation: "empty output")
-    }
-    let lines = String(decoding: rawLines, as: UTF8.self)
-            .trimmingCharacters(in: .whitespacesAndNewlines)
-            .components(separatedBy: "\n")
-
-    // Based on https://opensource.apple.com/source/network_cmds/network_cmds-606.40.2/arp.tproj/arp.c.auto.html
-    let regex = try NSRegularExpression(pattern: #"^.* \((?<ip>.*)\) at (?<mac>.*) on (?<interface>.*) .*$"#)
-
-    for line in lines {
-      let nsLineRange = NSRange(line.startIndex..<line.endIndex, in: line)
-
-      guard let match = regex.firstMatch(in: line, range: nsLineRange) else {
-        throw ARPCommandYieldedInvalidOutputError(explanation: "unparseable entry \"\(line)\"")
-      }
-
-      let rawIP = try match.getCaptureGroup(name: "ip", for: line)
-      guard let ip = IPv4Address(rawIP) else {
-        throw ARPCommandYieldedInvalidOutputError(explanation: "failed to parse IPv4 address \(rawIP)")
-      }
-
-      let rawMAC = try match.getCaptureGroup(name: "mac", for: line)
-      if rawMAC == "(incomplete)" {
-        continue
-      }
-      guard let mac = MACAddress(fromString: rawMAC) else {
-        throw ARPCommandYieldedInvalidOutputError(explanation: "failed to parse MAC address \(rawMAC)")
-      }
-
-      let interface = try match.getCaptureGroup(name: "interface", for: line)
-      if bridgeOnly && !interface.starts(with: "bridge") {
-        continue
-      }
-
-      if macAddress == mac {
-        return ip
-      }
-    }
-
-    return nil
-  }
-}
-
-extension NSTextCheckingResult {
-  func getCaptureGroup(name: String, for string: String) throws -> String {
-    let nsRange = self.range(withName: name)
-
-    if nsRange.location == NSNotFound {
-      throw ARPCacheInternalError(explanation: "attempted to retrieve non-existent named capture group \(name)")
-    }
-
-    guard let range = Range.init(nsRange, in: string) else {
-      throw ARPCacheInternalError(explanation: "failed to convert NSRange to Range")
-    }
-
-    return String(string[range])
-  }
-}

Sources/tart/Commands/Clone.swift

@@ -11,24 +11,34 @@ struct Clone: AsyncParsableCommand {
   @Argument(help: "new VM name")
   var newName: String
 
+  func validate() throws {
+    if newName.contains("/") {
+      throw ValidationError("<new-name> should be a local name")
+    }
+  }
+
   func run() async throws {
     do {
-      if let remoteName = try? RemoteName(sourceName) {
-        if !VMStorageOCI().exists(remoteName) {
-          // Pull the VM in case it's OCI-based and doesn't exist locally yet
-          let registry = try Registry(host: remoteName.host, namespace: remoteName.namespace)
-          try await VMStorageOCI().pull(remoteName, registry: registry)
-        }
-        let remoteVM = try VMStorageHelper.open(sourceName)
+      let ociStorage = VMStorageOCI()
+      let localStorage = VMStorageLocal()
 
-        let remoteConfig = try VMConfig.init(fromURL: remoteVM.configURL)
-        let needToGenerateNewMAC = try localVMExistsWith(macAddress: remoteConfig.macAddress.string)
-
-        try remoteVM.clone(to: VMStorageLocal().create(newName), generateMAC: needToGenerateNewMAC)
-      } else {
-        try VMStorageHelper.open(sourceName).clone(to: VMStorageLocal().create(newName), generateMAC: true)
+      if let remoteName = try? RemoteName(sourceName), !ociStorage.exists(remoteName) {
+        // Pull the VM in case it's OCI-based and doesn't exist locally yet
+        let registry = try Registry(host: remoteName.host, namespace: remoteName.namespace)
+        try await ociStorage.pull(remoteName, registry: registry)
       }
 
+      let sourceVM = try VMStorageHelper.open(sourceName)
+      let generateMAC = try localStorage.hasVMsWithMACAddress(macAddress: sourceVM.macAddress())
+
+      let tmpVMDir = try VMDirectory.temporary()
+      try await withTaskCancellationHandler(operation: {
+        try sourceVM.clone(to: tmpVMDir, generateMAC: generateMAC)
+        try localStorage.move(newName, from: tmpVMDir)
+      }, onCancel: {
+        try? FileManager.default.removeItem(at: tmpVMDir.baseURL)
+      })
+
       Foundation.exit(0)
     } catch {
       print(error)
@@ -36,15 +46,16 @@ struct Clone: AsyncParsableCommand {
       Foundation.exit(1)
     }
   }
+}
 
-  private func localVMExistsWith(macAddress: String) throws -> Bool {
-    var needToGenerateNewMAC = false
-    for (_, localDir) in try VMStorageLocal().list() {
-      let localConfig = try VMConfig.init(fromURL: localDir.configURL)
-      if localConfig.macAddress.string == macAddress {
-        needToGenerateNewMAC = true
-      }
-    }
-    return needToGenerateNewMAC
+fileprivate extension VMDirectory {
+  func macAddress() throws -> String {
+    try VMConfig(fromURL: configURL).macAddress.string
+  }
+}
+
+fileprivate extension VMStorageLocal {
+  func hasVMsWithMACAddress(macAddress: String) throws -> Bool {
+    try list().contains { try $1.macAddress() == macAddress }
   }
 }

Sources/tart/Commands/Create.swift

@@ -13,7 +13,7 @@ struct Create: AsyncParsableCommand {
   var fromIPSW: String?
 
   @Option(help: ArgumentHelp("Disk size in Gb")) 
-  var diskSize: UInt8 = 50
+  var diskSize: UInt16 = 50
 
   func validate() throws {
     if fromIPSW == nil {
@@ -23,13 +23,18 @@ struct Create: AsyncParsableCommand {
 
   func run() async throws {
     do {
-      let vmDir = try VMStorageLocal().create(name)
+      let tmpVMDir = try VMDirectory.temporary()
+      try await withTaskCancellationHandler(operation: {
+        if fromIPSW! == "latest" {
+          _ = try await VM(vmDir: tmpVMDir, ipswURL: nil, diskSizeGB: diskSize)
+        } else {
+          _ = try await VM(vmDir: tmpVMDir, ipswURL: URL(fileURLWithPath: fromIPSW!), diskSizeGB: diskSize)
+        }
 
-      if fromIPSW! == "latest" {
-        _ = try await VM(vmDir: vmDir, ipswURL: nil, diskSizeGB: diskSize)
-      } else {
-        _ = try await VM(vmDir: vmDir, ipswURL: URL(fileURLWithPath: fromIPSW!), diskSizeGB: diskSize)
-      }
+        try VMStorageLocal().move(name, from: tmpVMDir)
+      }, onCancel: {
+        try? FileManager.default.removeItem(at: tmpVMDir.baseURL)
+      })
 
       Foundation.exit(0)
     } catch {

Sources/tart/Commands/IP.swift

@@ -38,7 +38,7 @@ struct IP: AsyncParsableCommand {
     let vmMacAddress = MACAddress(fromString: config.macAddress.string)!
 
     repeat {
-      if let ip = try ARPCache.ResolveMACAddress(macAddress: vmMacAddress) {
+      if let ip = try Leases().resolveMACAddress(macAddress: vmMacAddress) {
         return ip
       }
 

Sources/tart/Commands/Login.swift

@@ -8,11 +8,46 @@ struct Login: AsyncParsableCommand {
   @Argument(help: "host")
   var host: String
 
+  @Option(help: "username")
+  var username: String?
+
+  @Flag(help: "password-stdin")
+  var passwordStdin: Bool = false
+
+  func validate() throws {
+    let usernameProvided = username != nil
+    let passwordProvided = passwordStdin
+
+    if usernameProvided != passwordProvided {
+      throw ValidationError("both --username and --password-stdin are required")
+    }
+  }
+
   func run() async throws {
     do {
-      let (user, password) = try Credentials.retrieveStdin()
+      var user: String
+      var password: String
 
-      try Credentials.store(host: host, user: user, password: password)
+      if let username = username {
+        user = username
+        password = readLine()!
+      } else {
+        (user, password) = try StdinCredentials.retrieve()
+      }
+      let credentialsProvider = DictionaryCredentialsProvider([
+        host: (user, password)
+      ])
+
+      do {
+        let registry = try Registry(host: host, namespace: "", credentialsProvider: credentialsProvider)
+        try await registry.ping()
+      } catch {
+        print("invalid credentials: \(error)")
+
+        Foundation.exit(1)
+      }
+
+      try KeychainCredentialsProvider().store(host: host, user: user, password: password)
 
       Foundation.exit(0)
     } catch {
@@ -22,3 +57,19 @@ struct Login: AsyncParsableCommand {
     }
   }
 }
+
+fileprivate class DictionaryCredentialsProvider: CredentialsProvider {
+  var credentials: Dictionary<String, (String, String)>
+
+  init(_ credentials: Dictionary<String, (String, String)>) {
+    self.credentials = credentials
+  }
+
+  func retrieve(host: String) throws -> (String, String)? {
+    credentials[host]
+  }
+
+  func store(host: String, user: String, password: String) throws {
+    credentials[host] = (user, password)
+  }
+}

Sources/tart/Commands/Push.swift

@@ -12,6 +12,10 @@ struct Push: AsyncParsableCommand {
   @Argument(help: "remote VM name(s)")
   var remoteNames: [String]
 
+  @Flag(help: ArgumentHelp("cache pushed images locally",
+          discussion: "Increases disk usage, but saves time if you're going to pull the pushed images later."))
+  var populateCache: Bool = false
+
   func run() async throws {
     do {
       let localVMDir = try VMStorageLocal().open(localName)
@@ -35,12 +39,20 @@ struct Push: AsyncParsableCommand {
       for (registryIdentifier, remoteNamesForRegistry) in registryGroups {
         let registry = try Registry(host: registryIdentifier.host, namespace: registryIdentifier.namespace)
 
-        let listOfTagsAndDigests = "{" + remoteNamesForRegistry.map{$0.fullyQualifiedReference }
-                .joined(separator: ",") + "}"
         defaultLogger.appendNewLine("pushing \(localName) to "
-          + "\(registryIdentifier.host)/\(registryIdentifier.namespace)\(listOfTagsAndDigests)...")
+          + "\(registryIdentifier.host)/\(registryIdentifier.namespace)\(remoteNamesForRegistry.referenceNames())...")
 
-        try await localVMDir.pushToRegistry(registry: registry, references: remoteNamesForRegistry.map{ $0.reference })
+        let pushedRemoteName = try await localVMDir.pushToRegistry(registry: registry, references: remoteNamesForRegistry.map{ $0.reference.value })
+
+        // Populate the local cache (if requested)
+        if populateCache {
+          let ociStorage = VMStorageOCI()
+          let expectedPushedVMDir = try ociStorage.create(pushedRemoteName)
+          try localVMDir.clone(to: expectedPushedVMDir, generateMAC: false)
+          for remoteName in remoteNamesForRegistry {
+            try ociStorage.link(from: remoteName, to: pushedRemoteName)
+          }
+        }
       }
 
       Foundation.exit(0)
@@ -51,3 +63,15 @@ struct Push: AsyncParsableCommand {
     }
   }
 }
+
+extension Collection where Element == RemoteName {
+  func referenceNames() -> String {
+    let references = self.map{ $0.reference.fullyQualified }
+
+    switch count {
+    case 0: return "∅"
+    case 1: return references.first!
+    default: return "{" + references.joined(separator: ",") + "}"
+    }
+  }
+}

Sources/tart/Commands/Run.swift

@@ -27,51 +27,63 @@ struct Run: AsyncParsableCommand {
           discussion: "Useful since VNC supports copy/paste, drag and drop, etc.\nNote that Remote Login option should be enabled inside the VM.")) 
   var vnc: Bool = false
 
+  @Flag var withSoftnet: Bool = false
+
   @MainActor
-  func run() async throws {
-    if recovery && vnc {
-      print("You can't run in recovery and use VNC!")
-      Foundation.exit(1)      
-    }
-    
+  func run() async throws {    
     let vmDir = try VMStorageLocal().open(name)
-    vm = try VM(vmDir: vmDir)
+    vm = try VM(vmDir: vmDir, withSoftnet: withSoftnet)
 
-    await withThrowingTaskGroup(of: Void.self) { group in
-      if vnc {
-        group.addTask(operation: {
-          do {
-            print("Waiting for the VM to boot...")
-            let resolvedIP = try await IP.resolveIP(vm!.config, secondsToWait: 60)
-            guard let ip = resolvedIP else {
-              throw IPNotFound()
-            }
-            let url = URL(string: "vnc://\(ip)")!
-            print("Opening \(url)")
+    var vncWrapper: VNCWrapper?
+
+    if vnc {
+        vncWrapper = VNCWrapper(virtualMachine: vm!.virtualMachine)
+    }
+
+    let task = Task {
+      do {
+        if let vncWrapper = vncWrapper {
+          let port = try await vncWrapper.waitForPort()
+
+          let url = URL(string: "vnc://:\(vncWrapper.password)@127.0.0.1:\(port)")!
+
+          if noGraphics || ProcessInfo.processInfo.environment["CI"] != nil {
+            print("VNC server is running at \(url)")
+          } else {
+            print("Opening \(url)...")
             NSWorkspace.shared.open(url)
-          } catch {
-            print("Failed to get an IP for screen sharing: \(error)")
           }
-        })
-      }
-      group.addTask {
-        do {
-          try await vm!.run(recovery)
-
-          Foundation.exit(0)
-        } catch {
-          print(error)
-
-          Foundation.exit(1)
         }
-      }
 
-      if noGraphics || vnc {
-        dispatchMain()
-      } else {
-        runUI()
+        try await vm!.run(recovery)
+
+        if let vncWrapper = vncWrapper {
+          try vncWrapper.stop()
+        }
+
+        Foundation.exit(0)
+      } catch {
+        if error.localizedDescription.contains("Failed to lock auxiliary storage.") {
+          print("Virtual machine \"\(name)\" is already running!")
+        } else {
+          print(error)
+        }
+
+        Foundation.exit(1)
       }
     }
+
+    let sigintSrc = DispatchSource.makeSignalSource(signal: SIGINT)
+    sigintSrc.setEventHandler {
+      task.cancel()
+    }
+    sigintSrc.activate()
+
+    if noGraphics || vnc {
+      dispatchMain()
+    } else {
+      runUI()
+    }
   }
 
   private func runUI() {

Sources/tart/Commands/Set.swift

@@ -2,7 +2,7 @@ import ArgumentParser
 import Foundation
 
 struct Set: AsyncParsableCommand {
-  static var configuration = CommandConfiguration(abstract: "Modify VM's configuration")
+  static var configuration = CommandConfiguration(commandName: "set", abstract: "Modify VM's configuration")
 
   @Argument(help: "VM name")
   var name: String
@@ -13,11 +13,11 @@ struct Set: AsyncParsableCommand {
   @Option(help: "VM memory size in megabytes")
   var memory: UInt16?
 
-  @Option(help: "VM display settings in a format of <width>x<height>(x<dpi>)?. For example, 1200x800 or 1200x800x72")
+  @Option(help: "VM display resolution in a format of <width>x<height>. For example, 1200x800")
   var display: VMDisplayConfig?
 
   @Option(help: .hidden)
-  var diskSize: UInt8?
+  var diskSize: UInt16?
 
   func run() async throws {
     do {
@@ -39,9 +39,6 @@ struct Set: AsyncParsableCommand {
         if (display.height > 0) {
           vmConfig.display.height = display.height
         }
-        if (display.dpi > 0) {
-          vmConfig.display.dpi = display.dpi
-        }
       }
 
       try vmConfig.save(toURL: vmDir.configURL)
@@ -66,8 +63,7 @@ extension VMDisplayConfig: ExpressibleByArgument {
     }
     self = VMDisplayConfig(
       width: parts[safe: 0] ?? 0,
-      height: parts[safe: 1] ?? 0,
-      dpi: parts[safe: 2] ?? 0
+      height: parts[safe: 1] ?? 0
     )
   }
 }

Sources/tart/Config.swift

@@ -6,4 +6,16 @@ struct Config {
           .appendingPathComponent(".tart", isDirectory: true)
 
   public static let tartCacheDir: URL = tartHomeDir.appendingPathComponent("cache", isDirectory: true)
+
+  static func jsonEncoder() -> JSONEncoder {
+    let encoder = JSONEncoder()
+
+    encoder.outputFormatting = [.sortedKeys]
+
+    return encoder
+  }
+
+  static func jsonDecoder() -> JSONDecoder {
+    JSONDecoder()
+  }
 }

Sources/tart/Credentials.swift

@@ -1,82 +0,0 @@
-import Foundation
-
-enum CredentialsError: Error {
-  case CredentialRequired(which: String)
-  case CredentialTooLong(message: String)
-}
-
-class Credentials {
-  static func retrieveKeychain(host: String) throws -> (String, String)? {
-    let query: [String: Any] = [kSecClass as String: kSecClassInternetPassword,
-                                kSecAttrProtocol as String: kSecAttrProtocolHTTPS,
-                                kSecAttrServer as String: host,
-                                kSecMatchLimit as String: kSecMatchLimitOne,
-                                kSecReturnAttributes as String: true,
-                                kSecReturnData as String: true,
-                                kSecAttrLabel as String: "Tart Credentials",
-    ]
-
-    var item: CFTypeRef?
-    let status = SecItemCopyMatching(query as CFDictionary, &item)
-
-    if status != errSecSuccess {
-      if status == errSecItemNotFound {
-        return nil
-      }
-
-      throw RegistryError.AuthFailed(why: "Keychain returned unsuccessful status \(status)")
-    }
-
-    guard let item = item as? [String: Any],
-          let user = item[kSecAttrAccount as String] as? String,
-          let passwordData = item[kSecValueData as String] as? Data,
-          let password = String(data: passwordData, encoding: .utf8)
-      else {
-      throw RegistryError.AuthFailed(why: "Keychain item has unexpected format")
-    }
-
-    return (user, password)
-  }
-
-  static func retrieveStdin() throws -> (String, String) {
-    let user = try readStdinCredential(name: "username", prompt: "User: ", isSensitive: false)
-    let password = try readStdinCredential(name: "password", prompt: "Password: ", isSensitive: true)
-
-    return (user, password)
-  }
-
-  private static func readStdinCredential(name: String, prompt: String, maxCharacters: Int = 255, isSensitive: Bool) throws -> String {
-    var buf = [CChar](repeating: 0, count: maxCharacters + 1 /* sentinel */ + 1 /* NUL */)
-    guard let rawCredential = readpassphrase(prompt, &buf, buf.count, isSensitive ? RPP_ECHO_OFF : RPP_ECHO_ON) else {
-      throw CredentialsError.CredentialRequired(which: name)
-    }
-
-    let credential = String(cString: rawCredential).trimmingCharacters(in: .newlines)
-
-    if credential.count > maxCharacters {
-      throw CredentialsError.CredentialTooLong(
-        message: "\(name) should contain no more than \(maxCharacters) characters")
-    }
-
-    return credential
-  }
-
-  static func store(host: String, user: String, password: String) throws {
-    let attributes: [String: Any] = [kSecClass as String: kSecClassInternetPassword,
-                                     kSecAttrAccount as String: user,
-                                     kSecAttrProtocol as String: kSecAttrProtocolHTTPS,
-                                     kSecAttrServer as String: host,
-                                     kSecValueData as String: password,
-                                     kSecAttrLabel as String: "Tart Credentials",
-    ]
-
-    let status = SecItemAdd(attributes as CFDictionary, nil)
-
-    switch status {
-    case errSecSuccess, errSecDuplicateItem:
-      return
-    default:
-      throw RegistryError.AuthFailed(why: "Keychain returned unsuccessful status \(status)")
-    }
-  }
-}

Sources/tart/Credentials/CredentialsProvider.swift

@@ -0,0 +1,10 @@
+import Foundation
+
+enum CredentialsProviderError: Error {
+    case Failed(message: String)
+}
+
+protocol CredentialsProvider {
+    func retrieve(host: String) throws -> (String, String)?
+    func store(host: String, user: String, password: String) throws
+}

Sources/tart/Credentials/KeychainCredentialsProvider.swift

@@ -0,0 +1,67 @@
+import Foundation
+
+class KeychainCredentialsProvider: CredentialsProvider {
+    func retrieve(host: String) throws -> (String, String)? {
+        let query: [String: Any] = [kSecClass as String: kSecClassInternetPassword,
+                                    kSecAttrProtocol as String: kSecAttrProtocolHTTPS,
+                                    kSecAttrServer as String: host,
+                                    kSecMatchLimit as String: kSecMatchLimitOne,
+                                    kSecReturnAttributes as String: true,
+                                    kSecReturnData as String: true,
+                                    kSecAttrLabel as String: "Tart Credentials",
+        ]
+
+        var item: CFTypeRef?
+        let status = SecItemCopyMatching(query as CFDictionary, &item)
+
+        if status != errSecSuccess {
+            if status == errSecItemNotFound {
+                return nil
+            }
+
+            throw CredentialsProviderError.Failed(message: "Keychain returned unsuccessful status \(status)")
+        }
+
+        guard let item = item as? [String: Any],
+              let user = item[kSecAttrAccount as String] as? String,
+              let passwordData = item[kSecValueData as String] as? Data,
+              let password = String(data: passwordData, encoding: .utf8)
+        else {
+            throw CredentialsProviderError.Failed(message: "Keychain item has unexpected format")
+        }
+
+        return (user, password)
+    }
+
+    func store(host: String, user: String, password: String) throws {
+        let passwordData = password.data(using: .utf8)
+        let attributes: [String: Any] = [kSecClass as String: kSecClassInternetPassword,
+                                         kSecAttrAccount as String: user,
+                                         kSecAttrProtocol as String: kSecAttrProtocolHTTPS,
+                                         kSecAttrServer as String: host,
+                                         kSecValueData as String: passwordData,
+                                         kSecAttrLabel as String: "Tart Credentials",
+        ]
+
+        let status = SecItemAdd(attributes as CFDictionary, nil)
+
+        switch status {
+        case errSecSuccess:
+            return
+        case errSecDuplicateItem:
+            let status = SecItemUpdate(attributes as CFDictionary,
+                [kSecValueData as String : passwordData] as CFDictionary)
+            if status != errSecSuccess {
+              throw CredentialsProviderError.Failed(message: "Keychain failed to update item: \(status.explanation())")
+            }
+        default:
+            throw CredentialsProviderError.Failed(message: "Keychain failed to add item: \(status.explanation())")
+        }
+    }
+}
+
+extension OSStatus {
+  func explanation() -> CFString {
+    SecCopyErrorMessageString(self, nil) ?? "Unknown status code \(self)." as CFString
+  }
+}

Sources/tart/Credentials/StdinCredentials.swift

@@ -0,0 +1,31 @@
+import Foundation
+
+enum StdinCredentialsError: Error {
+  case CredentialRequired(which: String)
+  case CredentialTooLong(message: String)
+}
+
+class StdinCredentials {
+  static func retrieve() throws -> (String, String) {
+    let user = try readStdinCredential(name: "username", prompt: "User: ", isSensitive: false)
+    let password = try readStdinCredential(name: "password", prompt: "Password: ", isSensitive: true)
+
+    return (user, password)
+  }
+
+  private static func readStdinCredential(name: String, prompt: String, maxCharacters: Int = 255, isSensitive: Bool) throws -> String {
+    var buf = [CChar](repeating: 0, count: maxCharacters + 1 /* sentinel */ + 1 /* NUL */)
+    guard let rawCredential = readpassphrase(prompt, &buf, buf.count, isSensitive ? RPP_ECHO_OFF : RPP_ECHO_ON) else {
+      throw StdinCredentialsError.CredentialRequired(which: name)
+    }
+
+    let credential = String(cString: rawCredential).trimmingCharacters(in: .newlines)
+
+    if credential.count > maxCharacters {
+      throw StdinCredentialsError.CredentialTooLong(
+        message: "\(name) should contain no more than \(maxCharacters) characters")
+    }
+
+    return credential
+  }
+}

Sources/tart/MACAddressResolver/Lease.swift

@@ -0,0 +1,32 @@
+import Network
+
+struct Lease {
+  var mac: MACAddress
+  var ip: IPv4Address
+
+  init?(fromRawLease: [String : String]) {
+    // Retrieve the required fields
+    guard let hwAddress = fromRawLease["hw_address"] else { return nil }
+    guard let ipAddress = fromRawLease["ip_address"] else { return nil }
+
+    // Parse MAC address
+    let hwAddressSplits = hwAddress.split(separator: ",")
+    if hwAddressSplits.count != 2 {
+      return nil
+    }
+    if let hwAddressProto = Int(hwAddressSplits[0]), hwAddressProto != ARPHRD_ETHER {
+      return nil
+    }
+    guard let mac = MACAddress(fromString: String(hwAddressSplits[1])) else {
+      return nil
+    }
+
+    // Parse IP address
+    guard let ip = IPv4Address(ipAddress) else {
+      return nil
+    }
+
+    self.ip = ip
+    self.mac = mac
+  }
+}

Sources/tart/MACAddressResolver/Leases.swift

@@ -0,0 +1,106 @@
+import Foundation
+import Network
+
+enum LeasesError: Error {
+  case UnexpectedFormat(name: String = "unexpected DHCPD leases file format", message: String, line: Int)
+  case Truncated(name: String = "truncated DHCPD leases file")
+
+  var description: String {
+    switch self {
+
+    case .UnexpectedFormat(name: let name, message: let message, line: let line):
+      return "\(name) on line \(line): \(message)"
+    case .Truncated(name: let name):
+      return "\(name)"
+    }
+  }
+}
+
+class Leases {
+  private let leases: [MACAddress : Lease]
+
+  convenience init() throws {
+    try self.init(URL(fileURLWithPath: "/var/db/dhcpd_leases"))
+  }
+
+  convenience init(_ fromURL: URL) throws {
+    let fileContents = try String(contentsOf: fromURL, encoding: .utf8)
+
+    try self.init(fileContents)
+  }
+
+  init(_ fromString: String) throws {
+    var leases: [MACAddress : Lease] = Dictionary()
+
+    for lease in try Self.retrieveRawLeases(fromString).compactMap({ Lease(fromRawLease: $0) }) {
+      leases[lease.mac] = lease
+    }
+
+    self.leases = leases
+  }
+
+  /// Parse leases from the host cache similarly to the PLCache_read() function found in Apple's Open Source releases.
+  ///
+  /// [1]: https://github.com/apple-opensource/bootp/blob/master/bootplib/NICache.c#L285-L391
+  private static func retrieveRawLeases(_ dhcpdLeasesContents: String) throws -> [[String : String]] {
+    var rawLeases: [[String : String]] = Array()
+
+    enum State {
+      case Nowhere
+      case Start
+      case Body
+      case End
+    }
+    var state = State.Nowhere
+
+    var currentRawLease: [String : String] = Dictionary()
+
+    for (lineNumber, line) in dhcpdLeasesContents.split(separator: "\n").enumerated().map({ ($0 + 1, $1) }) {
+      if line == "{" {
+        // Handle lease block start
+        if state != .Nowhere && state != .End {
+          throw LeasesError.UnexpectedFormat(message: "unexpected lease block start ({)", line: lineNumber)
+        }
+
+        state = .Start
+      } else if line == "}" {
+        // Handle lease block end
+        if state != .Body {
+          throw LeasesError.UnexpectedFormat(message: "unexpected lease block end (})", line: lineNumber)
+        }
+
+        rawLeases.append(currentRawLease)
+        currentRawLease = Dictionary()
+
+        state = .End
+      } else {
+        // Handle lease block contents
+        let lineWithoutTabs = String(line.drop { $0 == " " || $0 == "\t"})
+
+        if lineWithoutTabs.isEmpty {
+          continue
+        }
+
+        let splits = lineWithoutTabs.split(separator: "=", maxSplits: 1)
+        if splits.count != 2 {
+          throw LeasesError.UnexpectedFormat(message: "key-value pair with only a key", line: lineNumber)
+        }
+        let (key, value) = (String(splits[0]), String(splits[1]))
+
+        currentRawLease[key] = value
+
+        state = .Body
+      }
+    }
+
+    if state == .Start || state == .Body {
+      throw LeasesError.Truncated()
+    }
+
+    return rawLeases
+  }
+
+  func resolveMACAddress(macAddress: MACAddress) throws -> IPv4Address? {
+    leases[macAddress]?.ip
+  }
+}

Sources/tart/MACAddressResolver/MACAddress.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-struct MACAddress: Equatable, CustomStringConvertible {
+struct MACAddress: Equatable, Hashable, CustomStringConvertible {
   var mac: [UInt8] = Array(repeating: 0, count: 6)
 
   init?(fromString: String) {

Sources/tart/OCI/Authentication.swift

@@ -0,0 +1,21 @@
+import Foundation
+
+protocol Authentication {
+  func header() -> (String, String)
+  func isValid() -> Bool
+}
+
+struct BasicAuthentication: Authentication {
+  let user: String
+  let password: String
+
+  func header() -> (String, String) {
+    let creds = Data("\(user):\(password)".utf8).base64EncodedString()
+
+    return ("Authorization", "Basic \(creds)")
+  }
+
+  func isValid() -> Bool {
+    true
+  }
+}

Sources/tart/OCI/Manifest.swift

@@ -3,11 +3,55 @@ import Foundation
 let ociManifestMediaType = "application/vnd.oci.image.manifest.v1+json"
 let ociConfigMediaType = "application/vnd.oci.image.config.v1+json"
 
+// Annotations
+let uncompressedDiskSizeAnnotation = "org.cirruslabs.tart.uncompressed-disk-size"
+
 struct OCIManifest: Codable, Equatable {
   var schemaVersion: Int = 2
   var mediaType: String = ociManifestMediaType
   var config: OCIManifestConfig
   var layers: [OCIManifestLayer] = Array()
+  var annotations: Dictionary<String, String>?
+
+  init(config: OCIManifestConfig, layers: [OCIManifestLayer], uncompressedDiskSize: UInt64? = nil) {
+    self.config = config
+    self.layers = layers
+
+    if let uncompressedDiskSize = uncompressedDiskSize {
+      annotations = [
+        uncompressedDiskSizeAnnotation: String(uncompressedDiskSize)
+      ]
+    }
+  }
+
+  init(fromJSON: Data) throws {
+    self = try Config.jsonDecoder().decode(Self.self, from: fromJSON)
+  }
+
+  func toJSON() throws -> Data {
+    try Config.jsonEncoder().encode(self)
+  }
+
+  func digest() throws -> String {
+    try Digest.hash(toJSON())
+  }
+
+  func uncompressedDiskSize() -> UInt64? {
+    guard let value = annotations?[uncompressedDiskSizeAnnotation] else {
+      return nil
+    }
+
+    return UInt64(value)
+  }
+}
+
+struct OCIConfig: Codable {
+  var architecture: String = "arm64"
+  var os: String = "darwin"
+
+  func toJSON() throws -> Data {
+    try Config.jsonEncoder().encode(self)
+  }
 }
 
 struct OCIManifestConfig: Codable, Equatable {

Sources/tart/OCI/Registry.swift

@@ -25,7 +25,7 @@ extension HTTPClientResponse.Body {
   }
 }
 
-struct TokenResponse: Decodable {
+struct TokenResponse: Decodable, Authentication {
   let defaultIssuedAt = Date()
   let defaultExpiresIn = 60
 
@@ -34,7 +34,7 @@ struct TokenResponse: Decodable {
   var issuedAt: Date?
 
   static func parse(fromData: Data) throws -> Self {
-    let decoder = JSONDecoder()
+    let decoder = Config.jsonDecoder()
 
     decoder.keyDecodingStrategy = .convertFromSnakeCase
 
@@ -65,10 +65,12 @@ struct TokenResponse: Decodable {
     }
   }
 
-  var isValid: Bool {
-    get {
-      Date() < tokenExpiresAt
-    }
+  func header() -> (String, String) {
+    ("Authorization", "Bearer \(token)")
+  }
+
+  func isValid() -> Bool {
+    Date() < tokenExpiresAt
   }
 }
 
@@ -79,24 +81,33 @@ class Registry {
     try! httpClient.syncShutdown()
   }
   
-  var baseURL: URL
-  var namespace: String
+  let baseURL: URL
+  let namespace: String
+  let credentialsProvider: CredentialsProvider
 
-  var currentAuthToken: TokenResponse? = nil
+  var currentAuthToken: Authentication? = nil
 
-  init(urlComponents: URLComponents, namespace: String) throws {
+  init(urlComponents: URLComponents,
+       namespace: String,
+       credentialsProvider: CredentialsProvider = KeychainCredentialsProvider()
+  ) throws {
     baseURL = urlComponents.url!
     self.namespace = namespace
+    self.credentialsProvider = credentialsProvider
   }
 
-  convenience init(host: String, namespace: String) throws {
+  convenience init(
+          host: String,
+          namespace: String,
+          credentialsProvider: CredentialsProvider = KeychainCredentialsProvider()
+  ) throws {
     var baseURLComponents = URLComponents()
 
     baseURLComponents.scheme = "https"
     baseURLComponents.host = host
     baseURLComponents.path = "/v2/"
 
-    try self.init(urlComponents: baseURLComponents, namespace: namespace)
+    try self.init(urlComponents: baseURLComponents, namespace: namespace, credentialsProvider: credentialsProvider)
   }
 
   func ping() async throws {
@@ -107,7 +118,7 @@ class Registry {
   }
 
   func pushManifest(reference: String, manifest: OCIManifest) async throws -> String {
-    let manifestJSON = try JSONEncoder().encode(manifest)
+    let manifestJSON = try manifest.toJSON()
 
     let response = try await endpointRequest(.PUT, "\(namespace)/manifests/\(reference)",
       headers: ["Content-Type": manifest.mediaType],
@@ -130,7 +141,7 @@ class Registry {
     }
 
     let manifestData = try await response.body.readResponse()
-    let manifest = try JSONDecoder().decode(OCIManifest.self, from: manifestData)
+    let manifest = try OCIManifest(fromJSON: manifestData)
 
     return (manifest, manifestData)
   }
@@ -175,8 +186,8 @@ class Registry {
       body: fromData)
     if putResponse.status != .created {
       let body = try await postResponse.body.readTextResponse()
-      throw RegistryError.UnexpectedHTTPStatusCode(when: "pushing blob (PUT)", code: putResponse.status.code,
-        details: body ?? "")
+      throw RegistryError.UnexpectedHTTPStatusCode(when: "pushing blob (PUT) to \(uploadLocation)",
+              code: putResponse.status.code, details: body ?? "")
     }
 
     return digest
@@ -191,6 +202,8 @@ class Registry {
     }
 
     for try await part in response.body {
+      try Task.checkCancellation()
+
       try handler(part)
     }
   }
@@ -234,7 +247,7 @@ class Registry {
     }
 
     // Invalidate token if it has expired
-    if currentAuthToken?.isValid == false {
+    if currentAuthToken?.isValid() == false {
       currentAuthToken = nil
     }
 
@@ -255,6 +268,15 @@ class Registry {
     }
 
     let wwwAuthenticate = try WWWAuthenticate(rawHeaderValue: wwwAuthenticateRaw)
+
+    if wwwAuthenticate.scheme == "Basic" {
+      if let (user, password) = try credentialsProvider.retrieve(host: baseURL.host!) {
+        currentAuthToken = BasicAuthentication(user: user, password: password)
+      }
+
+      return
+    }
+
     if wwwAuthenticate.scheme != "Bearer" {
       throw RegistryError.AuthFailed(why: "WWW-Authenticate header's authentication scheme "
         + "\"\(wwwAuthenticate.scheme)\" is unsupported, expected \"Bearer\" scheme")
@@ -285,7 +307,7 @@ class Registry {
 
     var headers: Dictionary<String, String> = Dictionary()
 
-    if let (user, password) = try Credentials.retrieveKeychain(host: baseURL.host!) {
+    if let (user, password) = try credentialsProvider.retrieve(host: baseURL.host!) {
       let encodedCredentials = "\(user):\(password)".data(using: .utf8)?.base64EncodedString()
       headers["Authorization"] = "Basic \(encodedCredentials!)"
     }
@@ -305,7 +327,8 @@ class Registry {
     var request = request
 
     if let token = currentAuthToken {
-      request.headers.add(name: "Authorization", value: "Bearer \(token.token)")
+      let (name, value) = token.header()
+      request.headers.add(name: name, value: value)
     }
 
     return try await httpClient.execute(request, deadline: .distantFuture)

Sources/tart/OCI/RemoteName.swift

@@ -1,31 +1,57 @@
 import Foundation
 import Parsing
 
-struct Tail {
-  enum TailType {
+struct Reference: Comparable, Hashable, CustomStringConvertible {
+  enum ReferenceType: Comparable {
     case Tag
     case Digest
   }
 
-  var type: TailType
-  var value: String
-}
+  let type: ReferenceType
+  let value: String
 
-struct RemoteName: Comparable, CustomStringConvertible {
-  var host: String
-  var namespace: String
-  var reference: String = "latest"
-  var fullyQualifiedReference: String {
+  var fullyQualified: String {
     get {
-      if reference.starts(with: "sha256:") {
-        return "@" + reference
+      switch type {
+      case .Tag:
+        return ":" + value
+      case .Digest:
+        return "@" + value
       }
-
-      return ":" + reference
     }
   }
 
-  init(host: String, namespace: String, reference: String) {
+  init(tag: String) {
+    type = .Tag
+    value = tag
+  }
+
+  init(digest: String) {
+    type = .Digest
+    value = digest
+  }
+
+  static func <(lhs: Reference, rhs: Reference) -> Bool {
+    if lhs.type != rhs.type {
+      return lhs.type < rhs.type
+    } else {
+      return lhs.value < rhs.value
+    }
+  }
+
+  var description: String {
+    get {
+      fullyQualified
+    }
+  }
+}
+
+struct RemoteName: Comparable, Hashable, CustomStringConvertible {
+  var host: String
+  var namespace: String
+  var reference: Reference
+
+  init(host: String, namespace: String, reference: Reference) {
     self.host = host
     self.namespace = namespace
     self.reference = reference
@@ -58,13 +84,13 @@ struct RemoteName: Comparable, CustomStringConvertible {
           Parse {
             ":"
             csNormal.map {
-              Tail(type: .Tag, value: String($0))
+              Reference(tag: String($0))
             }
           }
           Parse {
             "@sha256:"
             csHex.map {
-              Tail(type: .Digest, value: "sha256:" + String($0))
+              Reference(digest: "sha256:" + String($0))
             }
           }
         }
@@ -76,9 +102,7 @@ struct RemoteName: Comparable, CustomStringConvertible {
 
     host = String(result.0)
     namespace = String(result.1)
-    if let tail = result.2 {
-      reference = tail.value
-    }
+    reference = result.2 ?? Reference(tag: "latest")
   }
 
   static func <(lhs: RemoteName, rhs: RemoteName) -> Bool {
@@ -92,7 +116,7 @@ struct RemoteName: Comparable, CustomStringConvertible {
   }
 
   var description: String {
-    "\(host)/\(namespace)\(fullyQualifiedReference)"
+    "\(host)/\(namespace)\(reference.fullyQualified)"
   }
 }
 

Sources/tart/Passphrase/PassphraseGenerator.swift

@@ -0,0 +1,13 @@
+import Foundation
+
+struct PassphraseGenerator: Sequence {
+    func makeIterator() -> PassphraseIterator {
+        PassphraseIterator()
+    }
+}
+
+struct PassphraseIterator: IteratorProtocol {
+    mutating func next() -> String? {
+        passphrases[Int(arc4random_uniform(UInt32(passphrases.count)))]
+    }
+}

Sources/tart/Root.swift

@@ -20,7 +20,10 @@ struct Root: AsyncParsableCommand {
     ])
 
   public static func main() async throws {
-    // Handle cancellation by Ctrl+C
+    // Ensure the default SIGINT handled is disabled,
+    // otherwise there's a race between two handlers
+    signal(SIGINT, SIG_IGN);
+    // Handle cancellation by Ctrl+C ourselves
     let task = withUnsafeCurrentTask { $0 }!
     let sigintSrc = DispatchSource.makeSignalSource(signal: SIGINT)
     sigintSrc.setEventHandler {

Sources/tart/Softnet.swift

@@ -0,0 +1,77 @@
+import Foundation
+
+enum SoftnetError: Error {
+  case InitializationFailed(why: String)
+}
+
+class Softnet {
+  private let process = Process()
+
+  let vmFD: Int32
+
+  init(vmMACAddress: String) throws {
+    let binaryName = "softnet"
+
+    guard let executableURL = Self.resolveBinaryPath(binaryName) else {
+      throw SoftnetError.InitializationFailed(why: "\(binaryName) not found in PATH")
+    }
+
+    let fds = UnsafeMutablePointer<Int32>.allocate(capacity: MemoryLayout<Int>.stride * 2)
+
+    let ret = socketpair(AF_UNIX, SOCK_DGRAM, 0, fds)
+    if ret != 0 {
+      throw SoftnetError.InitializationFailed(why: "socketpair() failed with exit code \(ret)")
+    }
+
+    vmFD = fds[0]
+    let softnetFD = fds[1]
+
+    try setSocketBuffers(vmFD, 1 * 1024 * 1024);
+    try setSocketBuffers(softnetFD, 1 * 1024 * 1024);
+
+    process.executableURL = executableURL
+    process.arguments = ["--vm-fd", String(STDIN_FILENO), "--vm-mac-address", vmMACAddress]
+    process.standardInput = FileHandle(fileDescriptor: softnetFD, closeOnDealloc: false)
+  }
+
+  func run() throws {
+    try process.run()
+  }
+
+  func stop() throws {
+    process.interrupt()
+    process.waitUntilExit()
+  }
+
+  private static func resolveBinaryPath(_ name: String) -> URL? {
+    guard let path = ProcessInfo.processInfo.environment["PATH"] else {
+      return nil
+    }
+
+    for pathComponent in path.split(separator: ":") {
+      let url = URL(fileURLWithPath: String(pathComponent))
+              .appendingPathComponent(name, isDirectory: false)
+
+      if FileManager.default.fileExists(atPath: url.path) {
+        return url
+      }
+    }
+
+    return nil
+  }
+
+  private func setSocketBuffers(_ fd: Int32, _ sizeBytes: Int) throws {
+    var option_value = sizeBytes
+    let option_len = socklen_t(MemoryLayout<Int>.size)
+
+    var ret = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &option_value, option_len)
+    if ret != 0 {
+      throw SoftnetError.InitializationFailed(why: "setsockopt(SO_RCVBUF) returned \(ret)")
+    }
+
+    ret = setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &option_value, option_len)
+    if ret != 0 {
+      throw SoftnetError.InitializationFailed(why: "setsockopt(SO_SNDBUF) returned \(ret)")
+    }
+  }
+}

Sources/tart/VM.swift

@@ -23,17 +23,24 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
   // VM's config
   var config: VMConfig
 
-  init(vmDir: VMDirectory) throws {
+  var softnet: Softnet? = nil
+
+  init(vmDir: VMDirectory, withSoftnet: Bool = false) throws {
     let auxStorage = VZMacAuxiliaryStorage(contentsOf: vmDir.nvramURL)
 
     name = vmDir.name
     config = try VMConfig.init(fromURL: vmDir.configURL)
 
-    let configuration = try VM.craftConfiguration(diskURL: vmDir.diskURL, auxStorage: auxStorage, vmConfig: config)
+    // Initialize the virtual machine and its configuration
+    if withSoftnet {
+      softnet = try Softnet(vmMACAddress: config.macAddress.string)
+    }
+
+    let configuration = try Self.craftConfiguration(diskURL: vmDir.diskURL, auxStorage: auxStorage, vmConfig: config,
+      softnet: softnet)
     virtualMachine = VZVirtualMachine(configuration: configuration)
 
     super.init()
-
     virtualMachine.delegate = self
   }
 
@@ -77,8 +84,17 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
     try data.write(to: expectedIPSWLocation, options: [.atomic])
     return expectedIPSWLocation
   }
+  
+  var inFinalState: Bool {
+    get {
+      virtualMachine.state == VZVirtualMachine.State.stopped ||
+        virtualMachine.state == VZVirtualMachine.State.paused ||
+        virtualMachine.state == VZVirtualMachine.State.error
+      
+    }
+  }
 
-  init(vmDir: VMDirectory, ipswURL: URL?, diskSizeGB: UInt8) async throws {
+  init(vmDir: VMDirectory, ipswURL: URL?, diskSizeGB: UInt16, withSoftnet: Bool = false) async throws {
     let ipswURL = ipswURL != nil ? ipswURL! : try await VM.retrieveLatestIPSW();
 
     // Load the restore image and try to get the requirements
@@ -111,11 +127,15 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
     try config.save(toURL: vmDir.configURL)
 
     // Initialize the virtual machine and its configuration
-    let configuration = try VM.craftConfiguration(diskURL: vmDir.diskURL, auxStorage: auxStorage, vmConfig: config)
+    if withSoftnet {
+      softnet = try Softnet(vmMACAddress: config.macAddress.string)
+    }
+
+    let configuration = try Self.craftConfiguration(diskURL: vmDir.diskURL, auxStorage: auxStorage, vmConfig: config,
+      softnet: softnet)
     virtualMachine = VZVirtualMachine(configuration: configuration)
 
     super.init()
-
     virtualMachine.delegate = self
 
     // Run automated installation
@@ -134,6 +154,10 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
   }
 
   func run(_ recovery: Bool) async throws {
+    if let softnet = softnet {
+      try softnet.run()
+    }
+
     try await virtualMachine.start(recovery)
 
     await withTaskCancellationHandler(operation: {
@@ -149,9 +173,18 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
         }
       }
     }
+
+    if let softnet = softnet {
+      try softnet.stop();
+    }
   }
 
-  static func craftConfiguration(diskURL: URL, auxStorage: VZMacAuxiliaryStorage, vmConfig: VMConfig) throws -> VZVirtualMachineConfiguration {
+  static func craftConfiguration(
+    diskURL: URL,
+    auxStorage: VZMacAuxiliaryStorage,
+    vmConfig: VMConfig,
+    softnet: Softnet? = nil
+  ) throws -> VZVirtualMachineConfiguration {
     let configuration = VZVirtualMachineConfiguration()
 
     // Boot loader
@@ -172,13 +205,24 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
 
     // Display
     let graphicsDeviceConfiguration = VZMacGraphicsDeviceConfiguration()
-    graphicsDeviceConfiguration.displays = [
-      VZMacGraphicsDisplayConfiguration(
-        widthInPixels: vmConfig.display.width,
-        heightInPixels: vmConfig.display.height,
-        pixelsPerInch: vmConfig.display.dpi
+    if let hostMainScreen = NSScreen.main {
+      let vmScreenSize = NSSize(
+        width: vmConfig.display.width,
+        height: vmConfig.display.height
       )
-    ]
+      graphicsDeviceConfiguration.displays = [
+        VZMacGraphicsDisplayConfiguration(for: hostMainScreen, sizeInPoints: vmScreenSize)
+      ]
+    } else {
+      graphicsDeviceConfiguration.displays = [
+        VZMacGraphicsDisplayConfiguration(
+          widthInPixels: vmConfig.display.width,
+          heightInPixels: vmConfig.display.height,
+          // Reasonable guess like https://developer.apple.com/documentation/coregraphics/1456599-cgdisplayscreensize    
+          pixelsPerInch: 72
+        )
+      ]
+    }
     configuration.graphicsDevices = [graphicsDeviceConfiguration]
 
     // Audio
@@ -192,7 +236,13 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
 
     // Networking
     let vio = VZVirtioNetworkDeviceConfiguration()
-    vio.attachment = VZNATNetworkDeviceAttachment()
+
+    if let softnet = softnet {
+      let fh = FileHandle.init(fileDescriptor: softnet.vmFD)
+      vio.attachment = VZFileHandleNetworkDeviceAttachment(fileHandle: fh)
+    } else {
+      vio.attachment = VZNATNetworkDeviceAttachment()
+    }
     vio.macAddress = vmConfig.macAddress
     configuration.networkDevices = [vio]
 

Sources/tart/VMConfig.swift

@@ -29,7 +29,6 @@ enum CodingKeys: String, CodingKey {
 struct VMDisplayConfig: Codable {
   var width: Int = 1024
   var height: Int = 768
-  var dpi: Int = 72
 }
 
 struct VMConfig: Codable {
@@ -60,12 +59,16 @@ struct VMConfig: Codable {
     memorySize = memorySizeMin
   }
 
-  init(fromData: Data) throws {
-    self = try JSONDecoder().decode(VMConfig.self, from: fromData)
+  init(fromJSON: Data) throws {
+    self = try Config.jsonDecoder().decode(Self.self, from: fromJSON)
   }
 
   init(fromURL: URL) throws {
-    self = try Self(fromData: try Data(contentsOf: fromURL))
+    self = try Self(fromJSON: try Data(contentsOf: fromURL))
+  }
+
+  func toJSON() throws -> Data {
+    try Config.jsonEncoder().encode(self)
   }
 
   func save(toURL: URL) throws {

Sources/tart/VMDirectory+OCI.swift

@@ -98,7 +98,7 @@ extension VMDirectory {
     try nvram.close()
   }
 
-  func pushToRegistry(registry: Registry, references: [String]) async throws {
+  func pushToRegistry(registry: Registry, references: [String]) async throws -> RemoteName {
     var layers = Array<OCIManifestLayer>()
 
     // Read VM's config and push it as blob
@@ -117,8 +117,10 @@ extension VMDirectory {
     // Read VM's compressed disk as chunks
     // and sequentially upload them as blobs
     let disk = try FileHandle(forReadingFrom: diskURL)
+    var diskReadBytes: UInt64 = 0
     let compressingFilter = try InputFilter<Data>(.compress, using: .lz4, bufferCapacity: Self.bufferSizeBytes) { _ in
       let data = try disk.read(upToCount: Self.bufferSizeBytes)
+      diskReadBytes += UInt64(data?.count ?? 0)
 
       progress.completedUnitCount += Int64(data?.count ?? 0)
 
@@ -137,16 +139,12 @@ extension VMDirectory {
     layers.append(OCIManifestLayer(mediaType: Self.nvramMediaType, size: nvram.count, digest: nvramDigest))
 
     // Craft a stub OCI config for Docker Hub compatibility
-    struct OCIConfig: Codable {
-      var architecture: String = "arm64"
-      var os: String = "darwin"
-    }
-
-    let ociConfigJSON = try JSONEncoder().encode(OCIConfig())
+    let ociConfigJSON = try OCIConfig().toJSON()
     let ociConfigDigest = try await registry.pushBlob(fromData: ociConfigJSON)
     let manifest = OCIManifest(
             config: OCIManifestConfig(size: ociConfigJSON.count, digest: ociConfigDigest),
-            layers: layers
+            layers: layers,
+            uncompressedDiskSize: diskReadBytes
     )
 
     // Manifest
@@ -155,6 +153,9 @@ extension VMDirectory {
 
       _ = try await registry.pushManifest(reference: reference, manifest: manifest)
     }
+
+    let pushedReference = Reference(digest: try manifest.digest())
+    return RemoteName(host: registry.baseURL.host!, namespace: registry.namespace, reference: pushedReference)
   }
 }
 

Sources/tart/VMDirectory.swift

@@ -24,6 +24,13 @@ struct VMDirectory {
     baseURL.lastPathComponent
   }
 
+  static func temporary() throws -> VMDirectory {
+    let tmpDir = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+    try FileManager.default.createDirectory(at: tmpDir, withIntermediateDirectories: false)
+
+    return VMDirectory(baseURL: tmpDir)
+  }
+
   var initialized: Bool {
     FileManager.default.fileExists(atPath: configURL.path) &&
       FileManager.default.fileExists(atPath: diskURL.path) &&
@@ -61,7 +68,7 @@ struct VMDirectory {
     try newVMConfig.save(toURL: to.configURL)
   }
 
-  func resizeDisk(_ sizeGB: UInt8) throws {
+  func resizeDisk(_ sizeGB: UInt16) throws {
     if !FileManager.default.fileExists(atPath: diskURL.path) {
       FileManager.default.createFile(atPath: diskURL.path, contents: nil, attributes: nil)
     }

Sources/tart/VMStorageLocal.swift

@@ -27,6 +27,11 @@ class VMStorageLocal {
     return vmDir
   }
 
+  func move(_ name: String, from: VMDirectory) throws {
+    _ = try FileManager.default.createDirectory(at: baseURL, withIntermediateDirectories: true)
+    _ = try FileManager.default.replaceItemAt(vmURL(name), withItemAt: from.baseURL)
+  }
+
   func delete(_ name: String) throws {
     try FileManager.default.removeItem(at: vmURL(name))
   }

Sources/tart/VMStorageOCI.swift

@@ -27,6 +27,17 @@ class VMStorageOCI {
     return vmDir
   }
 
+  func move(_ name: RemoteName, from: VMDirectory) throws{
+    let targetURL = vmURL(name)
+
+    // Pre-create intermediate directories (e.g. creates ~/.tart/cache/OCIs/github.com/org/repo/
+    // for github.com/org/repo:latest)
+    try FileManager.default.createDirectory(at: targetURL.deletingLastPathComponent(),
+            withIntermediateDirectories: true)
+
+    _ = try FileManager.default.replaceItemAt(targetURL, withItemAt: from.baseURL)
+  }
+
   func delete(_ name: RemoteName) throws {
     try FileManager.default.removeItem(at: vmURL(name))
   }
@@ -64,35 +75,43 @@ class VMStorageOCI {
   func pull(_ name: RemoteName, registry: Registry) async throws {
     defaultLogger.appendNewLine("pulling manifest...")
 
-    let (manifest, manifestData) = try await registry.pullManifest(reference: name.reference)
+    let (manifest, _) = try await registry.pullManifest(reference: name.reference.value)
+
+    var digestName = RemoteName(host: name.host, namespace: name.namespace,
+            reference: Reference(digest: try manifest.digest()))
 
-    // Create directory for manifest's digest
-    var digestName = name
-    digestName.reference = Digest.hash(manifestData)
     if !exists(digestName) {
-      let vmDir = try create(digestName)
-      try await vmDir.pullFromRegistry(registry: registry, manifest: manifest)
+      let tmpVMDir = try VMDirectory.temporary()
+      try await withTaskCancellationHandler(operation: {
+        try await tmpVMDir.pullFromRegistry(registry: registry, manifest: manifest)
+        try move(digestName, from: tmpVMDir)
+      }, onCancel: {
+        try? FileManager.default.removeItem(at: tmpVMDir.baseURL)
+      })
     } else {
-      defaultLogger.appendNewLine("\(digestName.reference) image is already cached! creating a symlink...")   
+      defaultLogger.appendNewLine("\(digestName) image is already cached! creating a symlink...")
     }
 
-    // Create directory for reference if it's different
-    if digestName != name {
+    if name != digestName {
       // Overwrite the old symbolic link
-      if FileManager.default.fileExists(atPath: vmURL(name).path) {
-        try FileManager.default.removeItem(at: vmURL(name))
-      }
-
-      try FileManager.default.createSymbolicLink(at: vmURL(name), withDestinationURL: vmURL(digestName))
+      try link(from: digestName, to: name)
     }
   }
+
+  func link(from: RemoteName, to: RemoteName) throws {
+    if FileManager.default.fileExists(atPath: vmURL(to).path) {
+      try FileManager.default.removeItem(at: vmURL(to))
+    }
+
+    try FileManager.default.createSymbolicLink(at: vmURL(to), withDestinationURL: vmURL(from))
+  }
 }
 
 extension URL {
   func appendingRemoteName(_ name: RemoteName) -> URL {
     var result: URL = self
 
-    for pathComponent in (name.host + "/" + name.namespace + "/" + name.reference).split(separator: "/") {
+    for pathComponent in (name.host + "/" + name.namespace + "/" + name.reference.value).split(separator: "/") {
       result = result.appendingPathComponent(String(pathComponent))
     }
 

Sources/tart/VNCWrapper.swift

@@ -0,0 +1,38 @@
+import Foundation
+import Dynamic
+import Virtualization
+
+class VNCWrapper {
+    let password: String
+    private let vnc: Dynamic
+
+    init(virtualMachine: VZVirtualMachine) {
+        password = Array(PassphraseGenerator().prefix(4)).joined(separator: "-")
+        let securityConfiguration = Dynamic._VZVNCAuthenticationSecurityConfiguration(password: password)
+        vnc = Dynamic._VZVNCServer(port: 0, queue: DispatchQueue.global(),
+                securityConfiguration: securityConfiguration)
+        vnc.virtualMachine = virtualMachine
+        vnc.start()
+    }
+
+    func stop() throws {
+        vnc.stop()
+    }
+
+    deinit {
+        try? stop()
+    }
+
+    func waitForPort() async throws -> UInt16 {
+        while true {
+            // Port is 0 shortly after start(),
+            // but will be initialized later
+            if let port = vnc.port.asUInt16, port != 0 {
+                return port
+            }
+
+            // Wait 50 ms.
+            try await Task.sleep(nanoseconds: 50_000_000)
+        }
+    }
+}

Tests/TartTests/MACAddressResolverTests.swift

@@ -0,0 +1,35 @@
+import XCTest
+import Network
+@testable import tart
+
+final class MACAddressResolverTests: XCTestCase {
+  func testSingleEntry() throws {
+    let leases = try Leases("""
+                            {
+                              ip_address=1.2.3.4
+                              hw_address=1,00:11:22:33:44:55
+                            }
+                            """)
+
+    XCTAssertEqual(IPv4Address("1.2.3.4"),
+      try leases.resolveMACAddress(macAddress: MACAddress(fromString: "00:11:22:33:44:55")!))
+  }
+
+  func testMultipleEntries() throws {
+    let leases = try Leases("""
+                            {
+                              ip_address=1.2.3.4
+                              hw_address=1,00:11:22:33:44:55
+                            }
+                            {
+                              ip_address=5.6.7.8
+                              hw_address=1,AA:BB:CC:DD:EE:FF
+                            }
+                            """)
+
+    XCTAssertEqual(IPv4Address("1.2.3.4"),
+      try leases.resolveMACAddress(macAddress: MACAddress(fromString: "00:11:22:33:44:55")!))
+    XCTAssertEqual(IPv4Address("5.6.7.8"),
+      try leases.resolveMACAddress(macAddress: MACAddress(fromString: "AA:BB:CC:DD:EE:FF")!))
+  }
+}

Tests/TartTests/RegistryTests.swift

@@ -62,11 +62,7 @@ final class RegistryTests: XCTestCase {
 
     func testPushPullManifest() async throws {
         // Craft a basic config
-        struct OCIConfig: Codable {
-            var architecture: String = "arm64"
-            var os: String = "darwin"
-        }
-        let configData = try JSONEncoder().encode(OCIConfig())
+        let configData = try OCIConfig().toJSON()
         let configDigest = try await registry.pushBlob(fromData: configData)
 
         // Craft a basic layer

Tests/TartTests/RemoteNameTests.swift

@@ -3,13 +3,13 @@ import XCTest
 
 final class RemoteNameTests: XCTestCase {
   func testTag() throws {
-    let expectedRemoteName = RemoteName(host: "ghcr.io", namespace: "a/b", reference: "latest")
+    let expectedRemoteName = RemoteName(host: "ghcr.io", namespace: "a/b", reference: Reference(tag: "latest"))
 
     XCTAssertEqual(expectedRemoteName, try RemoteName("ghcr.io/a/b:latest"))
   }
   
   func testComplexTag() throws {
-    let expectedRemoteName = RemoteName(host: "ghcr.io", namespace: "a/b", reference: "1.2.3-RC-1")
+    let expectedRemoteName = RemoteName(host: "ghcr.io", namespace: "a/b", reference: Reference(tag: "1.2.3-RC-1"))
 
     XCTAssertEqual(expectedRemoteName, try RemoteName("ghcr.io/a/b:1.2.3-RC-1"))
   }
@@ -18,7 +18,7 @@ final class RemoteNameTests: XCTestCase {
     let expectedRemoteName = RemoteName(
       host: "ghcr.io",
       namespace: "a/b",
-      reference: "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+      reference: Reference(digest: "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
     )
 
     XCTAssertEqual(expectedRemoteName,

Tests/TartTests/TokenResponseTests.swift

@@ -11,7 +11,7 @@ final class TokenResponseTests: XCTestCase {
     let expectedTokenExpiresAtRange = Date()...Date().addingTimeInterval(60)
     XCTAssertTrue(expectedTokenExpiresAtRange.contains(tokenResponse.tokenExpiresAt))
 
-    XCTAssertTrue(tokenResponse.isValid)
+    XCTAssertTrue(tokenResponse.isValid())
   }
 
   func testExpirationBasic() throws {
@@ -23,9 +23,9 @@ final class TokenResponseTests: XCTestCase {
     let expectedTokenExpiresAtRange = Date()...Date().addingTimeInterval(2)
     XCTAssertTrue(expectedTokenExpiresAtRange.contains(tokenResponse.tokenExpiresAt))
 
-    XCTAssertTrue(tokenResponse.isValid)
+    XCTAssertTrue(tokenResponse.isValid())
     _ = XCTWaiter.wait(for: [expectation(description: "Wait 3 seconds for the token to become invalid")], timeout: 2)
-    XCTAssertFalse(tokenResponse.isValid)
+    XCTAssertFalse(tokenResponse.isValid())
   }
 
   func testExpirationWithIssuedAt() throws {
@@ -33,6 +33,6 @@ final class TokenResponseTests: XCTestCase {
     let tokenResponse = try TokenResponse.parse(fromData: tokenResponseRaw)
 
     XCTAssertEqual(Date(timeIntervalSince1970: 3600), tokenResponse.tokenExpiresAt)
-    XCTAssertFalse(tokenResponse.isValid)
+    XCTAssertFalse(tokenResponse.isValid())
   }
 }