Full-fledged VNC support (#126)

Sources/tart/Commands/Run.swift

@@ -37,10 +37,16 @@ struct Run: AsyncParsableCommand {
     let vmDir = try VMStorageLocal().open(name)
     vm = try VM(vmDir: vmDir)
 
+    var vncWrapper: VNCWrapper?
+
+    if vnc {
+        vncWrapper = VNCWrapper(virtualMachine: vm!.virtualMachine)
+    }
+
     let runTask = Task {
       do {
         try await vm!.run(recovery)
-        
+
         // wait for VM to be in a final state before exit
         while !(vm?.inFinalState ?? false) {
           try await Task.sleep(nanoseconds: 1_000_000)
@@ -57,25 +63,27 @@ struct Run: AsyncParsableCommand {
         Foundation.exit(1)
       }
     }
-    if vnc {
+    if let vncWrapper = vncWrapper {
       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 (port, password) = try await vncWrapper.credentials()
+        let url = URL(string: "vnc://:\(password)@127.0.0.1:\(port)")!
+        print("Opening \(url)...")
+        if ProcessInfo.processInfo.environment["CI"] == nil {
+          NSWorkspace.shared.open(url)
         }
-        let url = URL(string: "vnc://\(ip)")!
-        print("Opening \(url)")
-        NSWorkspace.shared.open(url)
       } catch {
         print("Failed to get an IP for screen sharing: \(error)")
       }
     } else if !noGraphics {
       runUI()
     }
-    
+
     // wait for VM to get into a final state
     try await runTask.value
+
+    if let vncWrapper = vncWrapper {
+      try vncWrapper.stop()
+    }
   }
 
   private func runUI() {

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/VNCWrapper.swift

@@ -0,0 +1,42 @@
+import Foundation
+import Dynamic
+import Virtualization
+
+class VNCWrapper {
+    private 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 credentials() async throws -> (UInt16, String) {
+        (try await Self.waitForPort(vnc: vnc), password)
+    }
+
+    func stop() throws {
+        vnc.stop()
+    }
+
+    deinit {
+        try? stop()
+    }
+
+    private static func waitForPort(vnc: Dynamic) 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)
+        }
+    }
+}