tart clone: make pruning limit configurable (#1126)

* tart clone: make pruning limit configurable

* Fixed compilation

CONTRIBUTING.md

@@ -29,6 +29,7 @@ Table of Contents
 
 1. Code should follow camel case
 2. Code should follow [SwiftFormat](https://github.com/nicklockwood/SwiftFormat#swift-package-manager-plugin) guidelines. You can auto-format the code by running the following command:
+
 ```bash
 swift package plugin --allow-writing-to-package-directory swiftformat --cache ignore .
 ```

Package.resolved

@@ -1,5 +1,5 @@
 {
-  "originHash" : "c5371137580239f6928cf64425e754e77680bf24430b50f02dad5558c23f68b0",
+  "originHash" : "668bad809d4882f75f097e66a12a6dbc8e61ec998f1800a7e09439c854fadda1",
   "pins" : [
     {
       "identity" : "antlr4",
@@ -78,8 +78,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-argument-parser",
       "state" : {
-        "revision" : "41982a3656a71c768319979febd796c6fd111d5c",
-        "version" : "1.5.0"
+        "revision" : "309a47b2b1d9b5e991f36961c983ecec72275be3",
+        "version" : "1.6.1"
       }
     },
     {

Package.swift

@@ -10,7 +10,7 @@ let package = Package(
     .executable(name: "tart", targets: ["tart"])
   ],
   dependencies: [
-    .package(url: "https://github.com/apple/swift-argument-parser", from: "1.3.1"),
+    .package(url: "https://github.com/apple/swift-argument-parser", from: "1.6.1"),
     .package(url: "https://github.com/mhdhejazi/Dynamic", branch: "master"),
     .package(url: "https://github.com/apple/swift-algorithms", from: "1.2.0"),
     .package(url: "https://github.com/malcommac/SwiftDate", from: "7.0.0"),

README.md

@@ -66,8 +66,8 @@ Try running a Tart VM on your Apple Silicon device running macOS 13.0 (Ventura)
 
 ```bash
 brew install cirruslabs/cli/tart
-tart clone ghcr.io/cirruslabs/macos-sequoia-base:latest sequoia-base
-tart run sequoia-base
+tart clone ghcr.io/cirruslabs/macos-tahoe-base:latest tahoe-base
+tart run tahoe-base
 ```
 
 Please check the [official documentation](https://tart.run) for more information and/or feel free to use [discussions](https://github.com/cirruslabs/tart/discussions)

Sources/tart/Commands/Clone.swift

@@ -31,6 +31,9 @@ struct Clone: AsyncParsableCommand {
   @Flag(help: .hidden)
   var deduplicate: Bool = false
 
+  @Option(help: ArgumentHelp("limit automatic pruning to n gigabytes", valueName: "n"))
+  var pruneLimit: UInt = 100
+
   func validate() throws {
     if newName.contains("/") {
       throw ValidationError("<new-name> should be a local name")
@@ -76,8 +79,10 @@ struct Clone: AsyncParsableCommand {
       //
       // So, once we clone the VM let's try to claim the rest of space for the VM to run without errors.
       let unallocatedBytes = try sourceVM.sizeBytes() - sourceVM.allocatedSizeBytes()
-      if unallocatedBytes > 0 {
-        try Prune.reclaimIfNeeded(UInt64(unallocatedBytes), sourceVM)
+      // Avoid reclaiming an excessive amount of disk space.
+      let reclaimBytes = min(unallocatedBytes, Int(pruneLimit) * 1024 * 1024 * 1024)
+      if reclaimBytes > 0 {
+        try Prune.reclaimIfNeeded(UInt64(reclaimBytes), sourceVM)
       }
     }, onCancel: {
       try? FileManager.default.removeItem(at: tmpVMDir.baseURL)

Sources/tart/Commands/Exec.swift

@@ -87,11 +87,13 @@ struct Exec: AsyncParsableCommand {
         $0.args = Array(command.dropFirst(1))
         $0.interactive = interactive
         $0.tty = tty
-        $0.terminalSize = .with {
-          let (width, height) = try! Term.GetSize()
+        if tty {
+          $0.terminalSize = .with {
+            let (width, height) = try! Term.GetSize()
 
-          $0.cols = UInt32(width)
-          $0.rows = UInt32(height)
+            $0.cols = UInt32(width)
+            $0.rows = UInt32(height)
+          }
         }
       })
     })
@@ -100,28 +102,61 @@ struct Exec: AsyncParsableCommand {
     try await withThrowingTaskGroup { group in
       // Stream host's standard input if interactive mode is enabled
       if interactive {
-        let stdinStream = AsyncStream<Data> { continuation in
+        let stdinStream = AsyncThrowingStream<Data, Error> { continuation in
           let handle = FileHandle.standardInput
 
-          handle.readabilityHandler = { handle in
-            let data = handle.availableData
+          if isRegularFile(handle.fileDescriptor) {
+            // Standard input can be a regular file when input redirection (<) is used,
+            // in which case the handle won't receive any new readability events, so we
+            // just read the file normally here in chunks and consider done with it
+            //
+            // Ideally this is best handled by using non-blocking I/O, but Swift's
+            // standard library only offers inefficient bytes[1] property and SwiftNIO's
+            // NIOFileSystem doesn't seem to support opening raw file descriptors.
+            //
+            // [1]: https://developer.apple.com/documentation/foundation/filehandle/bytes
+            while true {
+              do {
+                let data = try handle.read(upToCount: 64 * 1024)
+                if let data = data {
+                  continuation.yield(data)
+                } else {
+                  continuation.finish()
+                  break
+                }
+              } catch (let error) {
+                continuation.finish(throwing: error)
+                break
+              }
+            }
+          } else {
+            handle.readabilityHandler = { handle in
+              let data = handle.availableData
 
-            continuation.yield(data)
-
-            if data.isEmpty {
-              continuation.finish()
+              if data.isEmpty {
+                continuation.finish()
+              } else {
+                continuation.yield(data)
+              }
             }
           }
         }
 
         group.addTask {
-          for await stdinData in stdinStream {
+          for try await stdinData in stdinStream {
             try await execCall.requestStream.send(.with {
               $0.type = .standardInput(.with {
                 $0.data = stdinData
               })
             })
           }
+
+          // Signal EOF as we're done reading standard input
+          try await execCall.requestStream.send(.with {
+            $0.type = .standardInput(.with {
+              $0.data = Data()
+            })
+          })
         }
       }
 
@@ -178,3 +213,13 @@ struct Exec: AsyncParsableCommand {
     }
   }
 }
+
+private func isRegularFile(_ fileDescriptor: Int32) -> Bool {
+  var stat = stat()
+
+  if fstat(fileDescriptor, &stat) != 0 {
+    return false
+  }
+
+  return (stat.st_mode & S_IFMT) == S_IFREG
+}

Sources/tart/Commands/Run.swift

@@ -116,10 +116,6 @@ struct Run: AsyncParsableCommand {
   #endif
   var vncExperimental: Bool = false
 
-  // Note that the valueName here should really be "path[:options]" instead of just "path",
-  // see ArgumentParser issue[1] for more details.
-  //
-  // [1]: https://github.com/apple/swift-argument-parser/issues/761
   @Option(help: ArgumentHelp("""
   Additional disk attachments with an optional read-only and synchronization options in the form of path[:options] (e.g. --disk="disk.bin", --disk="ubuntu.iso:ro", --disk="/dev/disk0", --disk "ghcr.io/cirruslabs/xcode:16.0:ro" or --disk="nbd://localhost:10809/myDisk:sync=none")
   """, discussion: """
@@ -143,7 +139,7 @@ struct Run: AsyncParsableCommand {
   To work around this pass TART_HOME explicitly:
 
   sudo TART_HOME="$HOME/.tart" tart run sequoia --disk=/dev/disk0
-  """, valueName: "path"), completion: .file())
+  """, valueName: "path[:options]"), completion: .file())
   var disk: [String] = []
 
   #if arch(arm64)
@@ -162,10 +158,6 @@ struct Run: AsyncParsableCommand {
   #endif
   var rosettaTag: String?
 
-  // Note that the valueName here should really be "[name:]path[:options]" instead of just "path",
-  // see ArgumentParser issue[1] for more details.
-  //
-  // [1]: https://github.com/apple/swift-argument-parser/issues/761
   @Option(help: ArgumentHelp("Additional directory shares with an optional read-only and mount tag options in the form of [name:]path[:options] (e.g. --dir=\"~/src/build\" or --dir=\"~/src/sources:ro\")", discussion: """
   Requires host to be macOS 13.0 (Ventura) or newer. macOS guests must be running macOS 13.0 (Ventura) or newer too.
 
@@ -178,7 +170,7 @@ struct Run: AsyncParsableCommand {
   Mount tag can be overridden by appending tag property to the directory share (e.g. --dir=\"~/src/build:tag=build\" or --dir=\"~/src/build:ro,tag=build\"). Then it can be mounted via "mount_virtiofs build ~/build" inside guest macOS and "mount -t virtiofs build ~/build" inside guest Linux.
 
   In case of passing multiple directories per mount tag it is required to prefix them with names e.g. --dir=\"build:~/src/build\" --dir=\"sources:~/src/sources:ro\". These names will be used as directory names under the mounting point inside guests. For the example above it will be "/Volumes/My Shared Files/build" and "/Volumes/My Shared Files/sources" respectively.
-  """, valueName: "path"), completion: .directory)
+  """, valueName: "[name:]path[:options]"), completion: .directory)
   var dir: [String] = []
 
   @Flag(help: ArgumentHelp("Enable nested virtualization if possible"))

Sources/tart/DiskImageFormat.swift

@@ -21,7 +21,7 @@ enum DiskImageFormat: String, CaseIterable, Codable {
     case .raw:
       return true
     case .asif:
-      if #available(macOS 15, *) {
+      if #available(macOS 26, *) {
         return true
       } else {
         return false

Sources/tart/ShellCompletions/ShellCompletions.swift

@@ -5,7 +5,7 @@ fileprivate func normalizeName(_ name: String) -> String {
   return name.replacingOccurrences(of: ":", with: "\\:")
 }
 
-func completeMachines(_ arguments: [String]) -> [String] {
+func completeMachines(_ arguments: [String], _ argumentIdx: Int, _ argumentPrefix: String) -> [String] {
   let localVMs = (try? VMStorageLocal().list().map { name, _ in
     normalizeName(name)
   }) ?? []
@@ -15,12 +15,12 @@ func completeMachines(_ arguments: [String]) -> [String] {
   return (localVMs + ociVMs)
 }
 
-func completeLocalMachines(_ arguments: [String]) -> [String] {
+func completeLocalMachines(_ arguments: [String], _ argumentIdx: Int, _ argumentPrefix: String) -> [String] {
   let localVMs = (try? VMStorageLocal().list()) ?? []
   return localVMs.map { name, _ in normalizeName(name) }
 }
 
-func completeRunningMachines(_ arguments: [String]) -> [String] {
+func completeRunningMachines(_ arguments: [String], _ argumentIdx: Int, _ argumentPrefix: String) -> [String] {
   let localVMs = (try? VMStorageLocal().list()) ?? []
   return localVMs
     .filter { _, vmDir in (try? vmDir.state() == .Running) ?? false}

Sources/tart/VMStorageOCI.swift

@@ -27,12 +27,12 @@ class VMStorageOCI: PrunableStorage {
     return digest
   }
 
-  func open(_ name: RemoteName) throws -> VMDirectory {
+  func open(_ name: RemoteName, _ accessDate: Date = Date()) throws -> VMDirectory {
     let vmDir = VMDirectory(baseURL: vmURL(name))
 
     try vmDir.validate(userFriendlyName: name.description)
 
-    try vmDir.baseURL.updateAccessDate()
+    try vmDir.baseURL.updateAccessDate(accessDate)
 
     return vmDir
   }
@@ -180,6 +180,10 @@ class VMStorageOCI: PrunableStorage {
       let transaction = SentrySDK.startTransaction(name: name.description, operation: "pull", bindToScope: true)
       let tmpVMDir = try VMDirectory.temporaryDeterministic(key: name.description)
 
+      // Open an existing VM directory corresponding to this name, if any,
+      // marking it as outdated to speed up the garbage collection process
+      _ = try? open(name, Date(timeIntervalSince1970: 0))
+
       // Lock the temporary VM directory to prevent it's garbage collection
       let tmpVMDirLock = try FileLock(lockURL: tmpVMDir.baseURL)
       try tmpVMDirLock.lock()

Tests/TartTests/DiskImageFormatTests.swift

@@ -2,13 +2,9 @@ import XCTest
 @testable import tart
 
 final class DiskImageFormatTests: XCTestCase {
-  func testRawFormatIsAlwaysSupported() throws {
-    XCTAssertTrue(DiskImageFormat.raw.isSupported)
-  }
-
   func testASIFFormatSupport() throws {
-    // ASIF should be supported on macOS 15+
-    if #available(macOS 15, *) {
+    // ASIF should be supported on macOS 26+
+    if #available(macOS 26, *) {
       XCTAssertTrue(DiskImageFormat.asif.isSupported)
     } else {
       XCTAssertFalse(DiskImageFormat.asif.isSupported)

docs/faq.md

@@ -166,6 +166,8 @@ Tart does have an analogue of Anka Controller for managing VMs across a cluster
 
 In case there's not enough space to fit the newly pulled or cloned VM image, Tart will remove the least recently accessed VMs from OCI cache and `.ipsw` files from IPSW cache until enough free space is available.
 
+The `tart clone` command limits this automatic pruning to 100 GB by default to avoid removing too many cached items. You can change this limit with the `--prune-limit` option (in gigabytes).
+
 To disable this functionality, set the `TART_NO_AUTO_PRUNE` environment variable either globally:
 
 ```shell

mkdocs.yml

@@ -46,6 +46,7 @@ plugins:
       match_path: blog/posts/.*
       date_from_meta:
         as_creation: date
+      abstract_chars_count: -1
   - social:
       cards_layout_dir: docs/layouts
       cards_layout: custom