Fixed packaging

* tart run: introduce --net-bridged

* tart.entitlements: add com.apple.vm.networking

.ci/create-pkg.sh

@@ -2,8 +2,10 @@
 
 set -e
 
+export VERSION="${CIRRUS_TAG:-0}"
+
 mkdir -p .ci/pkg/
 cp .build/arm64-apple-macosx/debug/tart .ci/pkg/
-pkgbuild --root .ci/pkg --version "${CIRRUS_TAG:-0}" --install-location /usr/local/bin/ --identifier com.github.cirruslabs.tart --sign "Developer ID Installer: Fedor Korotkov (9M2P8L4D89)" ./dist/Tart.pkg
-xcrun notarytool submit ./dist/Tart.pkg --keychain-profile "notarytool" --wait
-xcrun stapler staple ./dist/Tart.pkg
+pkgbuild --root .ci/pkg --version $VERSION --install-location /usr/local/bin/ --identifier com.github.cirruslabs.tart --sign "Developer ID Installer: Cirrus Labs, Inc. (9M2P8L4D89)" "./dist/Tart-$VERSION.pkg"
+xcrun notarytool submit "./dist/Tart-$VERSION.pkg" --keychain-profile "notarytool" --wait
+xcrun stapler staple "./dist/Tart-$VERSION.pkg"

.cirrus.yml

@@ -22,7 +22,7 @@ task:
   macos_instance:
     image: ghcr.io/cirruslabs/macos-ventura-xcode:latest
   env:
-    MACOS_CERTIFICATE: ENCRYPTED[8a6930a8c1286e7e536ea41b7647ea40e99174ad15e9cfcc753754fea55a619b355415629dff515b54a8921643e314e5]
+    MACOS_CERTIFICATE: ENCRYPTED[552b9d275d1c2bdbc1bff778b104a8f9a53cbd0d59344d4b7f6d0ca3c811a5cefb97bef9ba0ef31c219cb07bdacdd2c2]
     AC_PASSWORD: ENCRYPTED[4a761023e7e06fe2eb350c8b6e8e7ca961af193cb9ba47605f25f1d353abc3142606f412e405be48fd897a78787ea8c2]
     GITHUB_TOKEN: ENCRYPTED[!98ace8259c6024da912c14d5a3c5c6aac186890a8d4819fad78f3e0c41a4e0cd3a2537dd6e91493952fb056fa434be7c!]
     GORELEASER_KEY: ENCRYPTED[!9b80b6ef684ceaf40edd4c7af93014ee156c8aba7e6e5795f41c482729887b5c31f36b651491d790f1f668670888d9fd!]

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: [cirruslabs]

.goreleaser.yml

@@ -28,7 +28,7 @@ archives:
 release:
   prerelease: auto
   extra_files:
-    - glob: ./dist/Tart.pkg
+    - glob: ./dist/Tart-{{ .Tag }}.pkg
 
 brews:
   - name: tart

README.md

@@ -8,6 +8,22 @@ Built by CI engineers for your automation needs. Here are some highlights of Tar
 * Use Tart Packer Plugin to automate VM creation.
 * Built-in CI integration.
 
+*Tart* is already adopted by several automation services:
+
+<p align="center">
+  <a href="https://cirrus-ci.org/guide/macOS/" target=_blank>
+    <img src="https://github.com/cirruslabs/tart/raw/main/Resources/Users/CirrusCI.png" height="65"/>
+  </a>
+  <a href="https://codemagic.io/" target=_blank>
+    <img src="https://github.com/cirruslabs/tart/raw/main/Resources/Users/Codemagic.png" height="65"/>
+  </a>
+  <a href="https://testingbot.com/" target=_blank>
+    <img src="https://github.com/cirruslabs/tart/raw/main/Resources/Users/TestingBot.png" height="65"/>
+  </a>
+</p>
+
+## Usage
+
 Try running a Tart VM on your Apple Silicon device running macOS Monterey or later (will download a 25 GB image):
 
 ```shell
@@ -222,8 +238,8 @@ This invocation calls the `tart pull` implicitly (if the image is not being pres
 <details>
   <summary>Why Tart is free and open sourced?</summary>
 
-  Tart is a relatively small project, and it didn't feel right to try to monetize it.
-  Apple did all the heavy lifting with their `Virtualization.Framework`.
+  Apple did all the heavy lifting with their `Virtualization.Framework` and it just felt right to develop Tart in the open.
+  Please consider [becoming a sponsor](https://github.com/sponsors/cirruslabs) if you find Tart saving a substantial amount of money on licensing and engineering hours for your company.
 </details>
 
 <details>
@@ -252,3 +268,21 @@ This invocation calls the `tart pull` implicitly (if the image is not being pres
   Tart is limited by functionality of Apple's `Virtualization.Framework`. At the moment `Virtualization.Framework`
   doesn't support nested virtualization.
 </details>
+
+<details>
+  <summary>Changing the default NAT subnet</summary>
+
+  To change the default network to `192.168.77.1`:
+
+  ```
+  sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.vmnet.plist Shared_Net_Address -string 192.168.77.1
+  ```
+
+  Note that even through a network would normally be specified as `192.168.77.0`, the [vmnet framework](https://developer.apple.com/documentation/vmnet) seems to treat this as a starting address too and refuses to pick up such network-like values.
+
+  The default subnet mask `255.255.255.0` should suffice for most use-cases, however, you can also change it to `255.255.0.0`, for example:
+
+  ```
+  sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.vmnet.plist Shared_Net_Mask -string 255.255.0.0
+  ```
+</details>

Resources/Users/CirrusCI.png

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:dbcf6f65f26c0e17b2fe55a9712fc783315cd64905a0febce758b31d7e4e923b
+size 6787

Resources/Users/Codemagic.png

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4239996f30145992936cfc8faa0232fa8904aedf4de61e30ef4c4fc86cad587f
+size 14588

Resources/Users/TestingBot.png

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:227192fcd215c9cc05b1ebcd2616bd1f8c95be184726f64d91fc4507a88c66e1
+size 18393

Resources/tart.entitlements

@@ -4,5 +4,7 @@
 <dict>
 	<key>com.apple.security.virtualization</key>
 	<true/>
+	<key>com.apple.vm.networking</key>
+	<true/>
 </dict>
-</plist>
+</plist>

Sources/tart/Commands/Clone.swift

@@ -32,12 +32,22 @@ struct Clone: AsyncParsableCommand {
       }
 
       let sourceVM = try VMStorageHelper.open(sourceName)
-      let generateMAC = try localStorage.hasVMsWithMACAddress(macAddress: sourceVM.macAddress())
 
       let tmpVMDir = try VMDirectory.temporary()
+
+      // Lock the temporary VM directory to prevent it's garbage collection
+      let tmpVMDirLock = try FileLock(lockURL: tmpVMDir.baseURL)
+      try tmpVMDirLock.lock()
+
       try await withTaskCancellationHandler(operation: {
+        let lock = try FileLock(lockURL: Config().tartHomeDir)
+        try lock.lock()
+
+        let generateMAC = try localStorage.hasVMsWithMACAddress(macAddress: sourceVM.macAddress())
         try sourceVM.clone(to: tmpVMDir, generateMAC: generateMAC)
         try localStorage.move(newName, from: tmpVMDir)
+
+        try lock.unlock()
       }, onCancel: {
         try? FileManager.default.removeItem(at: tmpVMDir.baseURL)
       })

Sources/tart/Commands/Create.swift

@@ -27,6 +27,11 @@ struct Create: AsyncParsableCommand {
   func run() async throws {
     do {
       let tmpVMDir = try VMDirectory.temporary()
+
+      // Lock the temporary VM directory to prevent it's garbage collection
+      let tmpVMDirLock = try FileLock(lockURL: tmpVMDir.baseURL)
+      try tmpVMDirLock.lock()
+
       try await withTaskCancellationHandler(operation: {
         if let fromIPSW = fromIPSW {
           if fromIPSW == "latest" {

Sources/tart/Commands/Prune.swift

@@ -101,7 +101,7 @@ struct Prune: AsyncParsableCommand {
         break
       }
 
-      cacheReclaimedBytes -= try prunable.sizeBytes()
+      cacheReclaimedBytes += try prunable.sizeBytes()
       try prunable.delete()
     }
   }

Sources/tart/Commands/Rename.swift

@@ -0,0 +1,40 @@
+import ArgumentParser
+import Foundation
+
+struct Rename: AsyncParsableCommand {
+    static var configuration = CommandConfiguration(abstract: "Rename a VM")
+
+    @Argument(help: "VM name")
+    var name: String
+
+    @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 {
+            let localStorage = VMStorageLocal()
+
+            if !localStorage.exists(name) {
+                throw ValidationError("failed to rename a non-existent VM: \(name)")
+            }
+
+            if localStorage.exists(newName) {
+                throw ValidationError("failed to rename VM \(name), target VM \(name) already exists, delete it first!")
+            }
+
+            try localStorage.rename(name, newName)
+
+            Foundation.exit(0)
+        } catch {
+            print(error)
+
+            Foundation.exit(1)
+        }
+    }
+}

Sources/tart/Commands/Run.swift

@@ -47,15 +47,28 @@ struct Run: AsyncParsableCommand {
   @Option(help: ArgumentHelp("""
                              Additional directory shares with an optional read-only specifier\n(e.g. --dir=\"build:~/src/build\" --dir=\"sources:~/src/sources:ro\")
                              """, discussion: """
+                                              Requires host to be macOS 13.0 (Ventura) or newer.
                                               All shared directories are automatically mounted to "/Volumes/My Shared Files" directory on macOS,
                                               while on Linux you have to do it manually: "mount -t virtiofs com.apple.virtio-fs.automount /mount/point".
+                                              For macOS guests, they must be running macOS 13.0 (Ventura) or newer.
                                               """, valueName: "name:path[:ro]"))
   var dir: [String] = []
 
+  @Option(help: ArgumentHelp("""
+                             Use bridged networking instead of the default shared (NAT) networking \n(e.g. --net-bridged=en0 or --net-bridged=\"Wi-Fi\")
+                             """, discussion: """
+                                              Specify "list" as an interface name (--net-bridged=list) to list the available bridged interfaces.
+                                              """, valueName: "interface name"))
+  var netBridged: String?
+
   func validate() throws {
     if vnc && vncExperimental {
       throw ValidationError("--vnc and --vnc-experimental are mutually exclusive")
     }
+
+    if withSoftnet && netBridged != nil {
+      throw ValidationError("--with-softnet and --net-bridged are mutually exclusive")
+    }
   }
 
   @MainActor
@@ -63,7 +76,7 @@ struct Run: AsyncParsableCommand {
     let vmDir = try VMStorageLocal().open(name)
     vm = try VM(
       vmDir: vmDir,
-      withSoftnet: withSoftnet,
+      network: userSpecifiedNetwork(vmDir: vmDir) ?? NetworkShared(),
       additionalDiskAttachments: additionalDiskAttachments(),
       directoryShares: directoryShares()
     )
@@ -123,11 +136,53 @@ struct Run: AsyncParsableCommand {
     }
   }
 
+  func userSpecifiedNetwork(vmDir: VMDirectory) throws -> Network? {
+    if withSoftnet {
+      let config = try VMConfig.init(fromURL: vmDir.configURL)
+
+      return try Softnet(vmMACAddress: config.macAddress.string)
+    }
+
+    if let netBridged = netBridged {
+      let matchingInterfaces = VZBridgedNetworkInterface.networkInterfaces.filter { interface in
+        interface.identifier == netBridged || interface.localizedDisplayName == netBridged
+      }
+
+      if matchingInterfaces.isEmpty {
+        let available = bridgeInterfaces().joined(separator: ", ")
+        throw ValidationError("no bridge interfaces matched \"\(netBridged)\", "
+          + "available interfaces: \(available)")
+      }
+
+      if matchingInterfaces.count > 1 {
+        throw ValidationError("more than one bridge interface matched \"\(netBridged)\", "
+          + "consider refining the search criteria")
+      }
+
+      return NetworkBridged(interface: matchingInterfaces.first!)
+    }
+
+    return nil
+  }
+
+  func bridgeInterfaces() -> [String] {
+    VZBridgedNetworkInterface.networkInterfaces.map { interface in
+      var bridgeDescription = interface.identifier
+
+      if let localizedDisplayName = interface.localizedDisplayName {
+        bridgeDescription += " (or \"\(localizedDisplayName)\")"
+      }
+
+      return bridgeDescription
+    }
+  }
+
   func additionalDiskAttachments() throws -> [VZDiskImageStorageDeviceAttachment] {
     var result: [VZDiskImageStorageDeviceAttachment] = []
     let readOnlySuffix = ":ro"
+    let expandedDiskPaths = disk.map { NSString(string:$0).expandingTildeInPath }
 
-    for rawDisk in disk {
+    for rawDisk in expandedDiskPaths {
       if rawDisk.hasSuffix(readOnlySuffix) {
         result.append(try VZDiskImageStorageDeviceAttachment(
           url: URL(fileURLWithPath: String(rawDisk.prefix(rawDisk.count - readOnlySuffix.count))),
@@ -166,7 +221,7 @@ struct Run: AsyncParsableCommand {
 
       let (name, path) = (String(splits[0]), String(splits[1]))
 
-      result.append(DirectoryShare(name: name, path: URL(fileURLWithPath: path), readOnly: readOnly))
+      result.append(DirectoryShare(name: name, path: URL(fileURLWithPath: NSString(string: path).expandingTildeInPath), readOnly: readOnly))
     }
 
     return result

Sources/tart/Config.swift

@@ -3,8 +3,9 @@ import Foundation
 struct Config {
   let tartHomeDir: URL
   let tartCacheDir: URL
+  let tartTmpDir: URL
 
-  init() {
+  init() throws {
     var tartHomeDir: URL
 
     if let customTartHome = ProcessInfo.processInfo.environment["TART_HOME"] {
@@ -14,9 +15,27 @@ struct Config {
               .homeDirectoryForCurrentUser
               .appendingPathComponent(".tart", isDirectory: true)
     }
-
     self.tartHomeDir = tartHomeDir
+
     tartCacheDir = tartHomeDir.appendingPathComponent("cache", isDirectory: true)
+    try FileManager.default.createDirectory(at: tartCacheDir, withIntermediateDirectories: true)
+
+    tartTmpDir = tartHomeDir.appendingPathComponent("tmp", isDirectory: true)
+    try FileManager.default.createDirectory(at: tartTmpDir, withIntermediateDirectories: true)
+  }
+
+  func gc() throws {
+    for entry in try FileManager.default.contentsOfDirectory(at: tartTmpDir,
+        includingPropertiesForKeys: [], options: []) {
+      let lock = try FileLock(lockURL: entry)
+      if try !lock.trylock() {
+        continue
+      }
+
+      try FileManager.default.removeItem(at: entry)
+
+      try lock.unlock()
+    }
   }
 
   static func jsonEncoder() -> JSONEncoder {

Sources/tart/Credentials/DockerConfigCredentialsProvider.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-class HelperProgramCredentialsProvider: CredentialsProvider {
+class DockerConfigCredentialsProvider: CredentialsProvider {
   func retrieve(host: String) throws -> (String, String)? {
     let dockerConfigURL = FileManager.default.homeDirectoryForCurrentUser.appendingPathComponent(".docker").appendingPathComponent("config.json")
     if !FileManager.default.fileExists(atPath: dockerConfigURL.path) {
@@ -8,6 +8,9 @@ class HelperProgramCredentialsProvider: CredentialsProvider {
     }
     let config = try JSONDecoder().decode(DockerConfig.self, from: Data(contentsOf: dockerConfigURL))
 
+    if let credentialsFromAuth = config.auths?[host]?.decodeCredentials() {
+      return credentialsFromAuth
+    }
     if let helperProgram = config.credHelpers?[host] {
       return try executeHelper(binaryName: "docker-credential-\(helperProgram)", host: host)
     }
@@ -54,9 +57,31 @@ class HelperProgramCredentialsProvider: CredentialsProvider {
 }
 
 struct DockerConfig: Codable {
+  var auths: Dictionary<String, DockerAuthConfig>? = Dictionary()
   var credHelpers: Dictionary<String, String>? = Dictionary()
 }
 
+struct DockerAuthConfig: Codable {
+  var auth: String? = nil
+
+  func decodeCredentials() -> (String, String)? {
+    // auth is a base64("username:password")
+    guard let authBase64 = auth else {
+      return nil
+    }
+    guard let data = Data(base64Encoded: authBase64) else {
+      return nil
+    }
+    guard let components = String(data: data, encoding: .utf8)?.components(separatedBy: ":") else {
+      return nil
+    }
+    if components.count != 2 {
+      return nil
+    }
+    return (components[0], components[1])
+  }
+}
+
 struct DockerGetOutput: Codable {
   var Username: String
   var Secret: String

Sources/tart/FileLock.swift

@@ -0,0 +1,48 @@
+import Foundation
+import System
+
+enum FileLockError: Error, Equatable {
+    case Failed(_ message: String)
+    case AlreadyLocked
+}
+
+class FileLock {
+    let url: URL
+    let fd: Int32
+
+    init(lockURL: URL) throws {
+        url = lockURL
+        fd = open(lockURL.path, 0)
+    }
+
+    deinit {
+        close(fd)
+    }
+
+    func trylock() throws -> Bool {
+        try flockWrapper(LOCK_EX | LOCK_NB)
+    }
+
+    func lock() throws {
+        _ = try flockWrapper(LOCK_EX)
+    }
+
+    func unlock() throws {
+        _ = try flockWrapper(LOCK_UN)
+    }
+
+    func flockWrapper(_ operation: Int32) throws -> Bool {
+        let ret = flock(fd, operation)
+        if ret != 0 {
+            let details = Errno(rawValue: CInt(errno))
+
+            if (operation & LOCK_NB) != 0 && details == .wouldBlock {
+                return false
+            }
+
+            throw FileLockError.Failed("failed to lock \(url): \(details)")
+        }
+
+        return true
+    }
+}

Sources/tart/IPSWCache.swift

@@ -5,7 +5,7 @@ class IPSWCache: PrunableStorage {
   let baseURL: URL
 
   init() throws {
-    baseURL = Config().tartCacheDir.appendingPathComponent("IPSWs", isDirectory: true)
+    baseURL = try Config().tartCacheDir.appendingPathComponent("IPSWs", isDirectory: true)
     try FileManager.default.createDirectory(at: baseURL, withIntermediateDirectories: true)
   }
 

Sources/tart/Network/Network.swift

@@ -0,0 +1,7 @@
+import Virtualization
+
+protocol Network {
+  func attachment() -> VZNetworkDeviceAttachment
+  func run() throws
+  func stop() throws
+}

Sources/tart/Network/NetworkBridged.swift

@@ -0,0 +1,22 @@
+import Foundation
+import Virtualization
+
+class NetworkBridged: Network {
+    let interface: VZBridgedNetworkInterface
+
+    init(interface: VZBridgedNetworkInterface) {
+        self.interface = interface
+    }
+
+    func attachment() -> VZNetworkDeviceAttachment {
+        VZBridgedNetworkDeviceAttachment(interface: interface)
+    }
+
+    func run() throws {
+        // no-op, only used for Softnet
+    }
+
+    func stop() throws {
+        // no-op, only used for Softnet
+    }
+}

Sources/tart/Network/NetworkShared.swift

@@ -0,0 +1,16 @@
+import Foundation
+import Virtualization
+
+class NetworkShared: Network {
+    func attachment() -> VZNetworkDeviceAttachment {
+        VZNATNetworkDeviceAttachment()
+    }
+
+    func run() throws {
+        // no-op, only used for Softnet
+    }
+
+    func stop() throws {
+        // no-op, only used for Softnet
+    }
+}

Sources/tart/Network/Softnet.swift

@@ -1,10 +1,11 @@
 import Foundation
+import Virtualization
 
 enum SoftnetError: Error {
   case InitializationFailed(why: String)
 }
 
-class Softnet {
+class Softnet: Network {
   private let process = Process()
 
   let vmFD: Int32
@@ -57,4 +58,9 @@ class Softnet {
       throw SoftnetError.InitializationFailed(why: "setsockopt(SO_SNDBUF) returned \(ret)")
     }
   }
+
+  func attachment() -> VZNetworkDeviceAttachment {
+    let fh = FileHandle.init(fileDescriptor: vmFD)
+    return VZFileHandleNetworkDeviceAttachment(fileHandle: fh)
+  }
 }

Sources/tart/OCI/Registry.swift

@@ -94,7 +94,7 @@ class Registry {
 
   init(urlComponents: URLComponents,
        namespace: String,
-       credentialsProviders: [CredentialsProvider] = [HelperProgramCredentialsProvider(), KeychainCredentialsProvider()]
+       credentialsProviders: [CredentialsProvider] = [DockerConfigCredentialsProvider(), KeychainCredentialsProvider()]
   ) throws {
     baseURL = urlComponents.url!
     self.namespace = namespace
@@ -105,7 +105,7 @@ class Registry {
     host: String,
     namespace: String,
     insecure: Bool = false,
-    credentialsProviders: [CredentialsProvider] = [HelperProgramCredentialsProvider(), KeychainCredentialsProvider()]
+    credentialsProviders: [CredentialsProvider] = [DockerConfigCredentialsProvider(), KeychainCredentialsProvider()]
   ) throws {
     let proto = insecure ? "http" : "https"
     let baseURLComponents = URLComponents(string: proto + "://" + host + "/v2/")!

Sources/tart/Root.swift

@@ -17,6 +17,7 @@ struct Root: AsyncParsableCommand {
       Pull.self,
       Push.self,
       Prune.self,
+      Rename.self,
       Delete.self,
     ])
 
@@ -36,6 +37,9 @@ struct Root: AsyncParsableCommand {
     do {
       var command = try parseAsRoot()
 
+      // Run garbage-collection before each command (shouldn't take too long)
+      try Config().gc()
+
       if var asyncCommand = command as? AsyncParsableCommand {
         try await asyncCommand.run()
       } else {

Sources/tart/VM.swift

@@ -14,7 +14,7 @@ struct UnsupportedOSError: Error, CustomStringConvertible {
   let description: String
 
   init(_ what: String, _ plural: String) {
-    description = "error: \(what) \(plural) only supported on macOS 13.0 (Ventura) or newer"
+    description = "error: \(what) \(plural) only supported on hosts running macOS 13.0 (Ventura) or newer"
   }
 }
 
@@ -34,10 +34,10 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
   // VM's config
   var config: VMConfig
 
-  var softnet: Softnet? = nil
+  var network: Network
 
   init(vmDir: VMDirectory,
-       withSoftnet: Bool = false,
+       network: Network = NetworkShared(),
        additionalDiskAttachments: [VZDiskImageStorageDeviceAttachment] = [],
        directoryShares: [DirectoryShare] = []
   ) throws {
@@ -49,13 +49,10 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
     }
 
     // Initialize the virtual machine and its configuration
-    if withSoftnet {
-      softnet = try Softnet(vmMACAddress: config.macAddress.string)
-    }
-
+    self.network = network
     let configuration = try Self.craftConfiguration(diskURL: vmDir.diskURL,
       nvramURL: vmDir.nvramURL, vmConfig: config,
-      softnet: softnet, additionalDiskAttachments: additionalDiskAttachments,
+      network: network, additionalDiskAttachments: additionalDiskAttachments,
             directoryShares: directoryShares)
     virtualMachine = VZVirtualMachine(configuration: configuration)
 
@@ -114,7 +111,7 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
     vmDir: VMDirectory,
     ipswURL: URL?,
     diskSizeGB: UInt16,
-    withSoftnet: Bool = false,
+    network: Network = NetworkShared(),
     additionalDiskAttachments: [VZDiskImageStorageDeviceAttachment] = []
   ) async throws {
     let ipswURL = ipswURL != nil ? ipswURL! : try await VM.retrieveLatestIPSW();
@@ -149,12 +146,9 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
     try config.save(toURL: vmDir.configURL)
 
     // Initialize the virtual machine and its configuration
-    if withSoftnet {
-      softnet = try Softnet(vmMACAddress: config.macAddress.string)
-    }
-
+    self.network = network
     let configuration = try Self.craftConfiguration(diskURL: vmDir.diskURL, nvramURL: vmDir.nvramURL,
-      vmConfig: config, softnet: softnet,
+      vmConfig: config, network: network,
       additionalDiskAttachments: additionalDiskAttachments,
       directoryShares: [])
     virtualMachine = VZVirtualMachine(configuration: configuration)
@@ -193,9 +187,7 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
   }
 
   func run(_ recovery: Bool) async throws {
-    if let softnet = softnet {
-      try softnet.run()
-    }
+    try network.run()
 
     DispatchQueue.main.sync {
       Task {
@@ -225,16 +217,14 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
       }
     }
 
-    if let softnet = softnet {
-      try softnet.stop();
-    }
+    try network.stop()
   }
 
   static func craftConfiguration(
     diskURL: URL,
     nvramURL: URL,
     vmConfig: VMConfig,
-    softnet: Softnet? = nil,
+    network: Network = NetworkShared(),
     additionalDiskAttachments: [VZDiskImageStorageDeviceAttachment],
     directoryShares: [DirectoryShare]
   ) throws -> VZVirtualMachineConfiguration {
@@ -268,13 +258,7 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
 
     // Networking
     let vio = VZVirtioNetworkDeviceConfiguration()
-
-    if let softnet = softnet {
-      let fh = FileHandle.init(fileDescriptor: softnet.vmFD)
-      vio.attachment = VZFileHandleNetworkDeviceAttachment(fileHandle: fh)
-    } else {
-      vio.attachment = VZNATNetworkDeviceAttachment()
-    }
+    vio.attachment = network.attachment()
     vio.macAddress = vmConfig.macAddress
     configuration.networkDevices = [vio]
 

Sources/tart/VMDirectory.swift

@@ -29,7 +29,7 @@ struct VMDirectory: Prunable {
   }
 
   static func temporary() throws -> VMDirectory {
-    let tmpDir = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+    let tmpDir = try Config().tartTmpDir.appendingPathComponent(UUID().uuidString)
     try FileManager.default.createDirectory(at: tmpDir, withIntermediateDirectories: false)
 
     return VMDirectory(baseURL: tmpDir)

Sources/tart/VMStorageLocal.swift

@@ -1,7 +1,7 @@
 import Foundation
 
 class VMStorageLocal {
-  let baseURL: URL = Config().tartHomeDir.appendingPathComponent("vms", isDirectory: true)
+  let baseURL: URL = try! Config().tartHomeDir.appendingPathComponent("vms", isDirectory: true)
 
   private func vmURL(_ name: String) -> URL {
     baseURL.appendingPathComponent(name, isDirectory: true)
@@ -32,6 +32,10 @@ class VMStorageLocal {
     _ = try FileManager.default.replaceItemAt(vmURL(name), withItemAt: from.baseURL)
   }
 
+  func rename(_ name: String, _ newName: String) throws {
+    _ = try FileManager.default.replaceItemAt(vmURL(newName), withItemAt: vmURL(name))
+  }
+
   func delete(_ name: String) throws {
     try FileManager.default.removeItem(at: vmURL(name))
   }

Sources/tart/VMStorageOCI.swift

@@ -1,12 +1,16 @@
 import Foundation
 
 class VMStorageOCI: PrunableStorage {
-  let baseURL = Config().tartCacheDir.appendingPathComponent("OCIs", isDirectory: true)
+  let baseURL = try! Config().tartCacheDir.appendingPathComponent("OCIs", isDirectory: true)
 
   private func vmURL(_ name: RemoteName) -> URL {
     baseURL.appendingRemoteName(name)
   }
 
+  private func hostDirectoryURL(_ name: RemoteName) -> URL {
+    baseURL.appendingHost(name)
+  }
+
   func exists(_ name: RemoteName) -> Bool {
     VMDirectory(baseURL: vmURL(name)).initialized
   }
@@ -125,17 +129,41 @@ class VMStorageOCI: PrunableStorage {
     let digestName = RemoteName(host: name.host, namespace: name.namespace,
             reference: Reference(digest: Digest.hash(manifestData)))
 
+    // Ensure that host directory for given RemoteName exists in OCI storage
+    let hostDirectoryURL = hostDirectoryURL(digestName)
+    try FileManager.default.createDirectory(at: hostDirectoryURL, withIntermediateDirectories: true)
+
+    // Acquire a lock on it to prevent concurrent pulls for a single host
+    let lock = try FileLock(lockURL: hostDirectoryURL)
+
+    let sucessfullyLocked = try lock.trylock()
+    if !sucessfullyLocked {
+      print("waiting for lock...")
+      try lock.lock()
+    }
+    defer { try! lock.unlock() }
+
+    if Task.isCancelled {
+      throw CancellationError()
+    }
+
     if !exists(digestName) {
       let tmpVMDir = try VMDirectory.temporary()
 
+      // Lock the temporary VM directory to prevent it's garbage collection
+      let tmpVMDirLock = try FileLock(lockURL: tmpVMDir.baseURL)
+      try tmpVMDirLock.lock()
+
       // Try to reclaim some cache space if we know the VM size in advance
       if let uncompressedDiskSize = manifest.uncompressedDiskSize() {
         let requiredCapacityBytes = UInt64(uncompressedDiskSize + 128 * 1024 * 1024)
 
-        let attrs = try tmpVMDir.baseURL.resourceValues(forKeys: [.volumeAvailableCapacityForImportantUsageKey])
-        let availableCapacityBytes = UInt64(attrs.volumeAvailableCapacityForImportantUsage!)
+        let attrs = try Config().tartCacheDir.resourceValues(forKeys: [.volumeAvailableCapacityForImportantUsageKey, .volumeAvailableCapacityKey])
+        let availableCapacityBytes = max(UInt64(attrs.volumeAvailableCapacityForImportantUsage!), UInt64(attrs.volumeAvailableCapacity!))
 
-        if availableCapacityBytes < requiredCapacityBytes {
+        // There is a suspicious that occasionally capacity is returned as zero which can't be true.
+        // Let's validate to avoid unnecessary pruning.
+        if 0 < availableCapacityBytes && availableCapacityBytes < requiredCapacityBytes {
           try Prune.pruneReclaim(reclaimBytes: requiredCapacityBytes - availableCapacityBytes)
         }
       }
@@ -181,4 +209,8 @@ extension URL {
 
     return result
   }
+
+  func appendingHost(_ name: RemoteName) -> URL {
+    self.appendingPathComponent(name.host, isDirectory: true)
+  }
 }

Tests/TartTests/FileLockTests.swift

@@ -0,0 +1,34 @@
+import XCTest
+@testable import tart
+
+final class FileLockTests: XCTestCase {
+    func testSimple() throws {
+        // Create a temporary file that will be used as a lock
+        let url = temporaryFile()
+
+        // Make sure this file can be locked and unlocked
+        let lock = try FileLock(lockURL: url)
+        try lock.lock()
+        try lock.unlock()
+    }
+
+    func testDoubleLockResultsInError() throws {
+        // Create a temporary file that will be used as a lock
+        let url = temporaryFile()
+
+        // Create two locks on a same file and ensure one of them fails
+        let firstLock = try FileLock(lockURL: url)
+        try firstLock.lock()
+
+        let secondLock = try! FileLock(lockURL: url)
+        XCTAssertFalse(try secondLock.trylock())
+    }
+
+    private func temporaryFile() -> URL {
+        let url = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(UUID().uuidString)
+
+        FileManager.default.createFile(atPath: url.path, contents: nil)
+
+        return url
+    }
+}

gon.hcl

@@ -7,6 +7,6 @@ apple_id {
 }
 
 sign {
-  application_identity = "Developer ID Application: Fedor Korotkov"
+  application_identity = "Developer ID Application: Cirrus Labs, Inc."
   entitlements_file = "Resources/tart.entitlements"
 }