OCI storage: unconditionally remove the old link when link()'ing (#686)

* Highlight AWS Marketplace availability

* Updated image

* Changed height

README.md

@@ -65,6 +65,12 @@ Many more companies are using Tart in their internal setups. Here are a few of t
 
 **Note:** If your company or project is using Tart please consider [adding yourself to the list above](/Resources/Users/HowToAddYourself.md).
 
+<p align="center">
+  <a href="https://aws.amazon.com/marketplace/pp/prodview-qczco34wlkdws?utm_source=github&utm_medium=referral" target=_blank>
+    <img src="https://github.com/cirruslabs/tart/raw/main/Resources/AWSMarkeplaceLogo.png" height="90"/>
+  </a>
+</p>
+
 ## Usage
 
 Try running a Tart VM on your Apple Silicon device running macOS 13.0 (Ventura) or later (will download a 25 GB image):

Sources/tart/Commands/Run.swift

@@ -140,6 +140,12 @@ struct Run: AsyncParsableCommand {
         throw ValidationError("Suspending VMs with shared directories is not supported")
       }
     }
+
+    for disk in disk {
+      if disk.hasSuffix("-amd64.iso") {
+        throw ValidationError("Seems you have a disk targeting x86 architecture (hence amd64 in the name). Please use an 'arm64' version of the disk.")
+      }
+    }
   }
 
   @MainActor
@@ -218,7 +224,7 @@ struct Run: AsyncParsableCommand {
     // configuration file, otherwise we will loose the lock.
     //
     // [1]: https://man.openbsd.org/fcntl
-    let lock = try PIDLock(lockURL: vmDir.configURL)
+    let lock = try vmDir.lock()
     if try !lock.trylock() {
       throw RuntimeError.VMAlreadyRunning("VM \"\(name)\" is already running!")
     }
@@ -653,7 +659,7 @@ struct DirectoryShare {
 
     let archiveRequest = URLRequest(url: path, cachePolicy: .returnCacheDataElseLoad)
     var response: CachedURLResponse? = urlCache.cachedResponse(for: archiveRequest)
-    if (response == nil) {
+    if (response == nil || response?.data.isEmpty == true) {
       print("Downloading \(path)...")
       // download and unarchive remote directories if needed here
       // use old school API to prevent deadlocks since we are running via MainActor
@@ -661,8 +667,12 @@ struct DirectoryShare {
       Task {
         do {
           let (archiveData, archiveResponse) = try await URLSession.shared.data(for: archiveRequest)
-          urlCache.storeCachedResponse(CachedURLResponse(response: archiveResponse, data: archiveData, storagePolicy: .allowed), for: archiveRequest)
-          print("Cached for future invocations!")
+          if archiveData.isEmpty {
+            print("Remote archive is empty!")
+          } else {
+            urlCache.storeCachedResponse(CachedURLResponse(response: archiveResponse, data: archiveData, storagePolicy: .allowed), for: archiveRequest)
+            print("Cached for future invocations!")
+          }
         } catch {
           print("Download failed: \(error)")
         }

Sources/tart/Commands/Stop.swift

@@ -29,12 +29,12 @@ struct Stop: AsyncParsableCommand {
   }
 
   func stopRunning(_ vmDir: VMDirectory) async throws {
-    let lock = try PIDLock(lockURL: vmDir.configURL)
+    let lock = try vmDir.lock()
 
     // Find the VM's PID
     var pid = try lock.pid()
     if pid == 0 {
-      throw RuntimeError.VMNotRunning("VM \"\(name)\" is not running")
+      throw RuntimeError.VMNotRunning(name)
     }
 
     // Try to gracefully terminate the VM

Sources/tart/Commands/Suspend.swift

@@ -11,7 +11,7 @@ struct Suspend: AsyncParsableCommand {
 
   func run() async throws {
     let vmDir = try VMStorageLocal().open(name)
-    let lock = try PIDLock(lockURL: vmDir.configURL)
+    let lock = try vmDir.lock()
 
     // Find the VM's PID
     var pid = try lock.pid()

Sources/tart/VM.swift

@@ -326,9 +326,18 @@ class VM: NSObject, VZVirtualMachineDelegate, ObservableObject {
     }
 
     // Storage
-    var devices: [VZStorageDeviceConfiguration] = [
-      VZVirtioBlockDeviceConfiguration(attachment: try VZDiskImageStorageDeviceAttachment(url: diskURL, readOnly: false))
-    ]
+    let attachment: VZDiskImageStorageDeviceAttachment = vmConfig.os == .linux ?
+      // Use "cached" caching mode for virtio drive to prevent fs corruption on linux
+      try VZDiskImageStorageDeviceAttachment(url: diskURL, readOnly: false, cachingMode: .cached, synchronizationMode: .full) :
+      try VZDiskImageStorageDeviceAttachment(url: diskURL, readOnly: false)
+
+    var device: VZStorageDeviceConfiguration
+    if #available(macOS 14, *), vmConfig.os == .linux {
+      device = VZNVMExpressControllerDeviceConfiguration(attachment: attachment)
+    } else {
+      device = VZVirtioBlockDeviceConfiguration(attachment: attachment)
+    }
+    var devices: [VZStorageDeviceConfiguration] = [device]
     devices.append(contentsOf: additionalStorageDevices)
     configuration.storageDevices = devices
 

Sources/tart/VMDirectory.swift

@@ -30,13 +30,17 @@ struct VMDirectory: Prunable {
     baseURL
   }
 
+  func lock() throws -> PIDLock {
+    try PIDLock(lockURL: configURL)
+  }
+
   func running() throws -> Bool {
     // The most common reason why PIDLock() instantiation fails is a race with "tart delete" (ENOENT),
     // which is fine to report as "not running".
     //
     // The other reasons are unlikely and the cost of getting a false positive is way less than
     // the cost of crashing with an exception when calling "tart list" on a busy machine, for example.
-    guard let lock = try? PIDLock(lockURL: configURL) else {
+    guard let lock = try? lock() else {
       return false
     }
 
@@ -137,7 +141,15 @@ struct VMDirectory: Prunable {
   }
 
   func delete() throws {
+    let lock = try lock()
+
+    if try !lock.trylock() {
+      throw RuntimeError.VMIsRunning(name)
+    }
+
     try FileManager.default.removeItem(at: baseURL)
+
+    try lock.unlock()
   }
 
   func accessDate() throws -> Date {

Sources/tart/VMStorageHelper.swift

@@ -50,7 +50,8 @@ enum RuntimeError : Error {
   case VMConfigurationError(_ message: String)
   case VMDoesNotExist(name: String)
   case VMMissingFiles(_ message: String)
-  case VMNotRunning(_ message: String)
+  case VMIsRunning(_ name: String)
+  case VMNotRunning(_ name: String)
   case VMAlreadyRunning(_ message: String)
   case NoIPAddressFound(_ message: String)
   case DiskAlreadyInUse(_ message: String)
@@ -81,8 +82,10 @@ extension RuntimeError : CustomStringConvertible {
       return "the specified VM \"\(name)\" does not exist"
     case .VMMissingFiles(let message):
       return message
-    case .VMNotRunning(let message):
-      return message
+    case .VMIsRunning(let name):
+      return "VM \"\(name)\" is running"
+    case .VMNotRunning(let name):
+      return "VM \"\(name)\" is not running"
     case .VMAlreadyRunning(let message):
       return message
     case .NoIPAddressFound(let message):

Sources/tart/VMStorageLocal.swift

@@ -39,7 +39,7 @@ class VMStorageLocal: PrunableStorage {
   }
 
   func delete(_ name: String) throws {
-    try FileManager.default.removeItem(at: vmURL(name))
+    try VMDirectory(baseURL: vmURL(name)).delete()
   }
 
   func list() throws -> [(String, VMDirectory)] {

Sources/tart/VMStorageOCI.swift

@@ -219,9 +219,7 @@ class VMStorageOCI: PrunableStorage {
   }
 
   func link(from: RemoteName, to: RemoteName) throws {
-    if FileManager.default.fileExists(atPath: vmURL(from).path) {
-      try FileManager.default.removeItem(at: vmURL(from))
-    }
+    try? FileManager.default.removeItem(at: vmURL(from))
 
     try FileManager.default.createSymbolicLink(at: vmURL(from), withDestinationURL: vmURL(to))
 

docs/integrations/buildkite.md

@@ -0,0 +1,21 @@
+# Buildkite
+
+It is possible to run [Buildkite](https://buildkite.com/) pipeline steps in isolated ephemeral Tart Virtual Machines with the help of [Tart Buildkite Plugin](https://github.com/cirruslabs/tart-buildkite-plugin):
+
+![](/assets/images/BuildkiteTartPlugin.png)
+
+## Configuration
+
+The most basic configuration looks like this:
+
+```yaml
+steps:
+- command: uname -a
+  plugins:
+  - cirruslabs/tart#main:
+    image: ghcr.io/cirruslabs/macos-sonoma-base:latest
+```
+
+This will run `uname -r` in a macOS Tart VM cloned from `ghcr.io/cirruslabs/macos-sonoma-base:latest`.
+
+See plugin's [Configuration section](https://github.com/cirruslabs/tart-buildkite-plugin#configuration) for the full list of available options.

docs/quick-start.md

@@ -28,6 +28,38 @@ tart run sonoma-base
   <img src="https://github.com/cirruslabs/tart/raw/main/Resources/TartScreenshot.png"/>
 </p>
 
+## VM images
+
+The following macOS images are currently available:
+
+* macOS 14 (Sonoma)
+    * `ghcr.io/cirruslabs/macos-sonoma-vanilla:latest`
+    * `ghcr.io/cirruslabs/macos-sonoma-base:latest`
+    * `ghcr.io/cirruslabs/macos-sonoma-xcode:latest`
+* macOS 13 (Ventura)
+    * `ghcr.io/cirruslabs/macos-ventura-vanilla:latest`
+    * `ghcr.io/cirruslabs/macos-ventura-base:latest`
+    * `ghcr.io/cirruslabs/macos-ventura-xcode:latest`
+* macOS 12 (Monterey)
+    * `ghcr.io/cirruslabs/macos-monterey-vanilla:latest`
+    * `ghcr.io/cirruslabs/macos-monterey-base:latest`
+    * `ghcr.io/cirruslabs/macos-monterey-xcode:latest`
+
+There's also a [full list of images](https://github.com/orgs/cirruslabs/packages?tab=packages&q=macos-) in which you can discovery specific tags (e.g. `ghcr.io/cirruslabs/macos-monterey-xcode:15`) and [macOS-specific Packer templates](https://github.com/cirruslabs/macos-image-templates) that were used to generate these images.
+
+For, Linux the options are as follows:
+
+* Ubuntu
+    * `ghcr.io/cirruslabs/ubuntu:latest`
+* Debian
+    * `ghcr.io/cirruslabs/debian:latest`
+* Fedora
+    * `ghcr.io/cirruslabs/fedora:latest`
+
+These Linux images can be ran natively on [Vetu](https://github.com/cirruslabs/vetu), our virtualization solution for Linux, assuming that Vetu itself is running on an `arm64` machine.
+
+Similarly to macOS, there's also a [full list of images](https://github.com/orgs/cirruslabs/packages?repo_name=linux-image-templates) in which you can discovery specific tags (e.g. `ghcr.io/cirruslabs/ubuntu:22.04`) and [Linux-specific Packer templates](https://github.com/cirruslabs/linux-image-templates) that were used to generate these images.
+
 ## SSH access
 
 If the guest VM is running and configured to accept incoming SSH connections you can conveniently connect to it like so:

mkdocs.yml

@@ -91,6 +91,7 @@ nav:
   - "Integrations":
     - "GitHub Actions": integrations/github-actions.md
     - "GitLab Runner": integrations/gitlab-runner.md
+    - "Buildkite": integrations/buildkite.md
     - "Self-hosted CI": integrations/cirrus-cli.md
     - "Managing VMs": integrations/vm-management.md
   - "Support & Licensing": licensing.md