CI observability enhancements. (#1193)

- Adds a a `--log-root` option to `swift system start`, propagating the
value as `CONTAINER_LOG_ROOT` to services for logging to files instead
of the OS log facility. This is not a "production" capability as it
neither merges nor rotates logs.
- Currently we don't collect logs on CI builds, and we don't have
permission to run the `log` command there. The PR adds `--log-root` to
the CI test phase, archives the results, and uploads the archive as an
artifact.
- Use FilePath from swift-system for the log root. Foundation URL is a
bit of a footgun for filesystem paths, so unless we identify a
showstopper, we should incrementally transition to this type everywhere
except where we really need network URLs.
- Output the hostname of the CI runner at the start of the test phase so
we can identify runner-specific issues where they exist.
- Fix formatting for log messages with multiple metadata items, and fix
unstructured messages on instances that weren't found using `grep -r
'log\.' Sources`.
- Adds command reference documentation for `--log-root`.

Sources/ContainerCommands/Application.swift

@@ -172,6 +172,7 @@ public struct Application: AsyncLoggableCommand {
         return try PluginLoader(
             appRoot: systemHealth.appRoot,
             installRoot: systemHealth.installRoot,
+            logRoot: systemHealth.logRoot,
             pluginDirectories: pluginDirectories,
             pluginFactories: pluginFactories,
             log: bootstrapLogger

Sources/ContainerCommands/Image/ImageInspect.swift

@@ -63,9 +63,13 @@ extension Application {
             }
 
             if !allErrors.isEmpty {
-                let logger = Logger(label: "ImageInspect", factory: { _ in StderrLogHandler() })
                 for (name, error) in allErrors {
-                    logger.error("\(name): \(error.localizedDescription)")
+                    log.error(
+                        "image inspect failed",
+                        metadata: [
+                            "name": "\(name)",
+                            "error": "\(error.localizedDescription)",
+                        ])
                 }
 
                 throw InspectError(succeeded: succeededImages, failed: allErrors)

Sources/ContainerCommands/Network/NetworkDelete.swift

@@ -89,7 +89,7 @@ extension Application {
             }
 
             var failed = [String]()
-            let logger = log
+            let _log = log
             try await withThrowingTaskGroup(of: NetworkState?.self) { group in
                 for network in networks {
                     group.addTask {
@@ -100,7 +100,12 @@ extension Application {
                             print(network.id)
                             return nil
                         } catch {
-                            logger.error("failed to delete network \(network.id): \(error)")
+                            _log.error(
+                                "failed to delete network",
+                                metadata: [
+                                    "id": "\(network.id)",
+                                    "error": "\(error)",
+                                ])
                             return network
                         }
                     }

Sources/ContainerCommands/Network/NetworkPrune.swift

@@ -55,7 +55,12 @@ extension Application.NetworkCommand {
                     // Note: This failure may occur due to a race condition between the network/
                     // container collection above and a container run command that attaches to a
                     // network listed in the networksToPrune collection.
-                    log.error("failed to prune network", metadata: ["id": "\(network.id)", "error": "\(error)"])
+                    log.error(
+                        "failed to prune network",
+                        metadata: [
+                            "id": "\(network.id)",
+                            "error": "\(error)",
+                        ])
                 }
             }
 

Sources/ContainerCommands/System/SystemStart.swift

@@ -21,6 +21,7 @@ import ContainerPlugin
 import ContainerXPC
 import ContainerizationError
 import Foundation
+import SystemPackage
 import TerminalProgress
 
 extension Application {
@@ -42,6 +43,12 @@ extension Application {
             transform: { URL(filePath: $0) })
         var installRoot = InstallRoot.defaultURL
 
+        @Option(
+            name: .long,
+            help: "Path to the root directory for log data, using macOS log facility if not set",
+            transform: { FilePath($0) })
+        var logRoot: FilePath? = nil
+
         @Flag(
             name: .long,
             inversion: .prefixedEnableDisable,
@@ -85,7 +92,12 @@ extension Application {
             var env = PluginLoader.filterEnvironment()
             env[ApplicationRoot.environmentName] = appRoot.path(percentEncoded: false)
             env[InstallRoot.environmentName] = installRoot.path(percentEncoded: false)
-
+            if let logRoot {
+                env[LogRoot.environmentName] =
+                    logRoot.isAbsolute
+                    ? logRoot.string
+                    : FilePath(FileManager.default.currentDirectoryPath).appending(logRoot.components).string
+            }
             let plist = LaunchPlist(
                 label: "com.apple.container.apiserver",
                 arguments: args,

Sources/ContainerCommands/Volume/VolumeDelete.swift

@@ -68,7 +68,7 @@ extension Application.VolumeCommand {
             }
 
             var failed = [String]()
-            let logger = log
+            let _log = log
             try await withThrowingTaskGroup(of: Volume?.self) { group in
                 for volume in volumes {
                     group.addTask {
@@ -77,7 +77,12 @@ extension Application.VolumeCommand {
                             print(volume.id)
                             return nil
                         } catch {
-                            logger.error("failed to delete volume \(volume.id): \(error)")
+                            _log.error(
+                                "failed to delete volume",
+                                metadata: [
+                                    "id": "\(volume.id)",
+                                    "error": "\(error)",
+                                ])
                             return volume
                         }
                     }

Sources/ContainerLog/FileLogHandler.swift

@@ -0,0 +1,101 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2026 Apple Inc. and the container project authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//===----------------------------------------------------------------------===//
+
+import Foundation
+import Logging
+import SystemPackage
+
+/// Log handler that appends messages to a file, without any
+/// rotation or truncation strategy. Use for development purposes only.
+public struct FileLogHandler: LogHandler {
+    public var logLevel: Logger.Level = .info
+    public var metadata: Logger.Metadata = [:]
+
+    private let label: String
+    private let category: String
+    private let fileHandle: FileHandle
+
+    public subscript(metadataKey metadataKey: String) -> Logger.Metadata.Value? {
+        get {
+            self.metadata[metadataKey]
+        }
+        set {
+            self.metadata[metadataKey] = newValue
+        }
+    }
+
+    /// Create a log handler that appends to the specified file.
+    ///
+    /// - Parameters:
+    ///   - label: A unique identifier for the application.
+    ///   - category: An identifier for the application subsystem.
+    ///   - path: The log file location. The log handler creates the
+    ///     file and parent directory if needed.
+    /// - Returns: The log handler.
+    public init(label: String, category: String, path: FilePath) throws {
+        self.label = label
+        self.category = category
+        let parentPath = path.removingLastComponent()
+        try FileManager.default.createDirectory(atPath: parentPath.string, withIntermediateDirectories: true)
+        if !FileManager.default.fileExists(atPath: path.string) {
+            FileManager.default.createFile(atPath: path.string, contents: nil)
+        }
+        guard let handle = FileHandle(forWritingAtPath: path.string) else {
+            throw FileLogFailure.openFailed
+        }
+        self.fileHandle = handle
+        self.fileHandle.seekToEndOfFile()
+    }
+
+    public func log(
+        level: Logger.Level,
+        message: Logger.Message,
+        metadata: Logger.Metadata?,
+        source: String,
+        file: String,
+        function: String,
+        line: UInt
+    ) {
+        let timestampFormatter: ISO8601DateFormatter = {
+            let formatter = ISO8601DateFormatter()
+            formatter.formatOptions.insert(.withFractionalSeconds)
+            return formatter
+        }()
+        let timestamp = timestampFormatter.string(from: Date())
+
+        // Merge logger-level metadata with per-message metadata
+        var effectiveMetadata = self.metadata
+        if let metadata {
+            effectiveMetadata.merge(metadata) { _, new in new }
+        }
+
+        let text: String
+        if !effectiveMetadata.isEmpty {
+            text = "\(timestamp) [\(level)] \(label) \(category) \(effectiveMetadata.description): \(message)\n"
+        } else {
+            text = "\(timestamp) [\(level)] \(label): \(category) \(message)\n"
+        }
+        if let data = text.data(using: .utf8) {
+            fileHandle.write(data)
+        }
+    }
+
+    /// Failures relating to the log handler.
+    public enum FileLogFailure: Error {
+        /// The log handler could not open the log file.
+        case openFailed
+    }
+}

Sources/ContainerLog/ServiceLogger.swift

@@ -0,0 +1,74 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2026 Apple Inc. and the container project authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//===----------------------------------------------------------------------===//
+
+import Logging
+import SystemPackage
+
+/// Common logging setup for application services.
+public struct ServiceLogger {
+    /// Set up the logging system and create a root logger.
+    ///
+    /// - Parameters:
+    ///   - label: A unique identifier for the application.
+    ///   - category: An identifier for the application subsystem.
+    ///   - metadata: Metadata to include for all messsages. A message
+    ///     specific value for a duplicate key overrides these values.
+    ///   - debug: Enable debug logging.
+    ///   - logPath: If supplied, create log files under the named
+    ///     directory. Otherwise, log to the OS log facility.
+    /// - Returns: The root logger.
+    public static func bootstrap(
+        label: String = "com.apple.container",
+        category: String,
+        metadata: [String: String] = [:],
+        debug: Bool,
+        logPath: FilePath?
+    ) -> Logger {
+        // Select the log handler and bootstrap logging.
+        LoggingSystem.bootstrap { label in
+            if let logPath {
+                if let handler = try? FileLogHandler(
+                    label: label,
+                    category: category,
+                    path: logPath
+                ) {
+                    return handler
+                }
+            }
+            return OSLogHandler(label: label, category: category)
+        }
+
+        // Configure log level and metadata.
+        var log = Logger(label: label)
+        if debug {
+            log.logLevel = .debug
+        }
+        for (key, value) in metadata {
+            log[metadataKey: key] = "\(value)"
+        }
+
+        // Log an error if for some reason FileLogHandler init failed.
+        if let logPath, log.handler as? OSLogHandler != nil {
+            log.error(
+                "unable to initialize FileLogHandler, using OSLogHandler",
+                metadata: [
+                    "logPath": "\(logPath)"
+                ])
+        }
+
+        return log
+    }
+}

Sources/ContainerPlugin/LogRoot.swift

@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2026 Apple Inc. and the container project authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//===----------------------------------------------------------------------===//
+
+import Foundation
+import SystemPackage
+
+/// Provides the application data root path.
+public struct LogRoot {
+
+    private static let envPath = ProcessInfo.processInfo.environment[Self.environmentName].flatMap {
+        $0.isEmpty ? nil : FilePath($0)
+    }
+
+    /// The environment variable that if set, determines the root directory for log files.
+    /// Otherwise, the application uses the macOS log facility.
+    public static let environmentName = "CONTAINER_LOG_ROOT"
+
+    /// The path object for the log file root directory
+    public static let path = envPath.map {
+        guard !$0.isAbsolute else { return $0 }
+        return FilePath(FileManager.default.currentDirectoryPath).appending($0.components)
+    }
+
+    /// The pathname to the log file root directory
+    public static let pathname = path?.string
+}

Sources/ContainerPlugin/PluginLoader.swift

@@ -17,12 +17,15 @@
 import ContainerizationOS
 import Foundation
 import Logging
+import SystemPackage
 
 public struct PluginLoader: Sendable {
     private let appRoot: URL
 
     private let installRoot: URL
 
+    private let logRoot: FilePath?
+
     private let pluginDirectories: [URL]
 
     private let pluginFactories: [PluginFactory]
@@ -39,6 +42,7 @@ public struct PluginLoader: Sendable {
     public init(
         appRoot: URL,
         installRoot: URL,
+        logRoot: FilePath?,
         pluginDirectories: [URL],
         pluginFactories: [PluginFactory],
         log: Logger? = nil
@@ -48,6 +52,7 @@ public struct PluginLoader: Sendable {
         self.pluginResourceRoot = pluginResourceRoot
         self.appRoot = appRoot
         self.installRoot = installRoot
+        self.logRoot = logRoot
         self.pluginDirectories = pluginDirectories
         self.pluginFactories = pluginFactories
         self.log = log
@@ -223,6 +228,12 @@ extension PluginLoader {
         var env = Self.filterEnvironment()
         env[ApplicationRoot.environmentName] = appRoot.path(percentEncoded: false)
         env[InstallRoot.environmentName] = installRoot.path(percentEncoded: false)
+        if let logRoot {
+            env[LogRoot.environmentName] =
+                logRoot.isAbsolute
+                ? logRoot.string
+                : FilePath(FileManager.default.currentDirectoryPath).appending(logRoot.components).string
+        }
 
         let processedArgs = (args ?? ["start"]) + (debug ? ["--debug"] : [])
         let plist = LaunchPlist(

Sources/ContainerXPC/XPCServer.swift

@@ -199,14 +199,24 @@ public struct XPCServer: Sendable {
                 let response = try await handler(message)
                 xpc_connection_send_message(connection, response.underlying)
             } catch let error as ContainerizationError {
-                log.error("route handler threw an error", metadata: ["route": "\(route)", "error": "\(error)"])
+                log.error(
+                    "route handler threw an error",
+                    metadata: [
+                        "route": "\(route)",
+                        "error": "\(error)",
+                    ])
                 Self.replyWithError(
                     connection: connection,
                     object: object,
                     err: error
                 )
             } catch {
-                log.error("route handler threw an error", metadata: ["route": "\(route)", "error": "\(error)"])
+                log.error(
+                    "route handler threw an error",
+                    metadata: [
+                        "route": "\(route)",
+                        "error": "\(error)",
+                    ])
                 let message = XPCMessage(object: object)
                 let reply = message.reply()
 

Sources/Helpers/APIServer/APIServer+Start.swift

@@ -17,6 +17,7 @@
 import ArgumentParser
 import ContainerAPIClient
 import ContainerAPIService
+import ContainerLog
 import ContainerNetworkService
 import ContainerPlugin
 import ContainerResource
@@ -24,6 +25,7 @@ import ContainerXPC
 import DNSServer
 import Foundation
 import Logging
+import SystemPackage
 
 extension APIServer {
     struct Start: AsyncParsableCommand {
@@ -43,9 +45,12 @@ extension APIServer {
 
         var installRoot = InstallRoot.url
 
+        var logRoot = LogRoot.path
+
         func run() async throws {
-            let commandName = Self.configuration.commandName ?? "container-apiserver"
-            let log = APIServer.setupLogger(debug: debug)
+            let commandName = APIServer._commandName
+            let logPath = logRoot.map { $0.appending("\(commandName).log") }
+            let log = ServiceLogger.bootstrap(category: "APIServer", debug: debug, logPath: logPath)
             log.info("starting helper", metadata: ["name": "\(commandName)"])
             defer {
                 log.info("stopping helper", metadata: ["name": "\(commandName)"])
@@ -91,6 +96,7 @@ extension APIServer {
                         log.info("starting XPC server")
                         try await server.listen()
                     }
+
                     // start up host table DNS
                     group.addTask {
                         let hostsResolver = ContainerDNSHandler(networkService: networkService)
@@ -113,7 +119,12 @@ extension APIServer {
                     /*
                     group.addTask {
                         let localhostResolver = LocalhostDNSHandler(log: log)
-                        try localhostResolver.monitorResolvers()
+                        do {
+                            try localhostResolver.monitorResolvers()
+                        } catch {
+                            log.error("could not initialize resolver monitor", metadata: ["error": "\(error)"])
+                            throw error
+                        }
                     
                         let nxDomainResolver = NxDomainResolver()
                         let compositeResolver = CompositeResolver(handlers: [localhostResolver, nxDomainResolver])
@@ -131,7 +142,12 @@ extension APIServer {
                     */
                 }
             } catch {
-                log.error("helper failed", metadata: ["name": "\(commandName)", "error": "\(error)"])
+                log.error(
+                    "helper failed",
+                    metadata: [
+                        "name": "\(commandName)",
+                        "error": "\(error)",
+                    ])
                 APIServer.exit(withError: error)
             }
         }
@@ -178,6 +194,7 @@ extension APIServer {
             return try PluginLoader(
                 appRoot: appRoot,
                 installRoot: installRoot,
+                logRoot: logRoot,
                 pluginDirectories: pluginDirectories,
                 pluginFactories: pluginFactories,
                 log: log
@@ -209,7 +226,12 @@ extension APIServer {
         private func initializeHealthCheckService(log: Logger, routes: inout [XPCRoute: XPCServer.RouteHandler]) {
             log.info("initializing health check service")
 
-            let svc = HealthCheckHarness(appRoot: appRoot, installRoot: installRoot, log: log)
+            let svc = HealthCheckHarness(
+                appRoot: appRoot,
+                installRoot: installRoot,
+                logRoot: logRoot,
+                log: log
+            )
             routes[XPCRoute.ping] = svc.ping
         }
 

Sources/Helpers/APIServer/APIServer.swift

@@ -15,9 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 import ArgumentParser
-import ContainerLog
 import ContainerVersion
-import Logging
 
 @main
 struct APIServer: AsyncParsableCommand {
@@ -27,18 +25,4 @@ struct APIServer: AsyncParsableCommand {
         version: ReleaseVersion.singleLine(appName: "container-apiserver"),
         subcommands: [Start.self],
     )
-
-    static func setupLogger(debug: Bool) -> Logger {
-        LoggingSystem.bootstrap { label in
-            OSLogHandler(
-                label: label,
-                category: "APIServer"
-            )
-        }
-        var log = Logger(label: "com.apple.container")
-        if debug {
-            log.logLevel = .debug
-        }
-        return log
-    }
 }

Sources/Helpers/APIServer/DirectoryWatcher.swift

@@ -66,7 +66,12 @@ public class DirectoryWatcher {
                 let files = try FileManager.default.contentsOfDirectory(atPath: directoryURL.path)
                 try handler(files.map { directoryURL.appending(path: $0) })
             } catch {
-                self.log.error("failed to run DirectoryWatcher handler", metadata: ["error": "\(error)", "path": "\(directoryURL.path)"])
+                self.log.error(
+                    "failed to run DirectoryWatcher handler",
+                    metadata: [
+                        "error": "\(error)",
+                        "path": "\(directoryURL.path)",
+                    ])
             }
         }
 

Sources/Helpers/Images/ImagesHelper.swift

@@ -54,11 +54,14 @@ extension ImagesHelper {
 
         var installRoot = InstallRoot.url
 
+        var logRoot = LogRoot.path
+
         private static let unpackStrategy = SnapshotStore.defaultUnpackStrategy
 
         func run() async throws {
             let commandName = ImagesHelper._commandName
-            let log = setupLogger()
+            let logPath = logRoot.map { $0.appending("\(commandName).log") }
+            let log = ServiceLogger.bootstrap(category: "ImagesHelper", debug: debug, logPath: logPath)
             log.info("starting helper", metadata: ["name": "\(commandName)"])
             defer {
                 log.info("stopping helper", metadata: ["name": "\(commandName)"])
@@ -77,7 +80,12 @@ extension ImagesHelper {
                 log.info("starting XPC server")
                 try await xpc.listen()
             } catch {
-                log.error("helper failed", metadata: ["name": "\(commandName)", "error": "\(error)"])
+                log.error(
+                    "helper failed",
+                    metadata: [
+                        "name": "\(commandName)",
+                        "error": "\(error)",
+                    ])
                 ImagesHelper.exit(withError: error)
             }
         }
@@ -114,19 +122,5 @@ extension ImagesHelper {
             routes[ImagesServiceXPCRoute.contentIngestCancel.rawValue] = harness.cancelIngestSession
             routes[ImagesServiceXPCRoute.contentIngestComplete.rawValue] = harness.completeIngestSession
         }
-
-        private func setupLogger() -> Logger {
-            LoggingSystem.bootstrap { label in
-                OSLogHandler(
-                    label: label,
-                    category: "ImagesHelper"
-                )
-            }
-            var log = Logger(label: "com.apple.container")
-            if debug {
-                log.logLevel = .debug
-            }
-            return log
-        }
     }
 }

Sources/Helpers/NetworkVmnet/NetworkVmnetHelper+Start.swift

@@ -15,8 +15,10 @@
 //===----------------------------------------------------------------------===//
 
 import ArgumentParser
+import ContainerLog
 import ContainerNetworkService
 import ContainerNetworkServiceClient
+import ContainerPlugin
 import ContainerResource
 import ContainerXPC
 import ContainerizationError
@@ -64,9 +66,12 @@ extension NetworkVmnetHelper {
             return .reserved
         }()
 
+        var logRoot = LogRoot.path
+
         func run() async throws {
             let commandName = NetworkVmnetHelper._commandName
-            let log = setupLogger(id: id, debug: debug)
+            let logPath = logRoot.map { $0.appending("\(commandName)-\(id).log") }
+            let log = ServiceLogger.bootstrap(category: "NetworkVmnetHelper", metadata: ["id": "\(id)"], debug: debug, logPath: logPath)
             log.info("starting helper", metadata: ["name": "\(commandName)"])
             defer {
                 log.info("stopping helper", metadata: ["name": "\(commandName)"])
@@ -110,7 +115,12 @@ extension NetworkVmnetHelper {
                 log.info("starting XPC server")
                 try await xpc.listen()
             } catch {
-                log.error("helper failed", metadata: ["name": "\(commandName)", "error": "\(error)"])
+                log.error(
+                    "helper failed",
+                    metadata: [
+                        "name": "\(commandName)",
+                        "error": "\(error)",
+                    ])
                 NetworkVmnetHelper.exit(withError: error)
             }
         }

Sources/Helpers/NetworkVmnet/NetworkVmnetHelper.swift

@@ -15,9 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 import ArgumentParser
-import ContainerLog
 import ContainerVersion
-import Logging
 
 @main
 struct NetworkVmnetHelper: AsyncParsableCommand {
@@ -29,19 +27,4 @@ struct NetworkVmnetHelper: AsyncParsableCommand {
             Start.self
         ]
     )
-
-    static func setupLogger(id: String, debug: Bool) -> Logger {
-        LoggingSystem.bootstrap { label in
-            OSLogHandler(
-                label: label,
-                category: "NetworkVmnetHelper"
-            )
-        }
-        var log = Logger(label: "com.apple.container")
-        if debug {
-            log.logLevel = .debug
-        }
-        log[metadataKey: "id"] = "\(id)"
-        return log
-    }
 }

Sources/Helpers/RuntimeLinux/RuntimeLinuxHelper+Start.swift

@@ -16,6 +16,7 @@
 
 import ArgumentParser
 import ContainerLog
+import ContainerPlugin
 import ContainerResource
 import ContainerSandboxService
 import ContainerSandboxServiceClient
@@ -42,13 +43,16 @@ extension RuntimeLinuxHelper {
         @Option(name: .shortAndLong, help: "Root directory for the sandbox")
         var root: String
 
+        var logRoot = LogRoot.path
+
         var machServiceLabel: String {
             "\(Self.label).\(uuid)"
         }
 
         func run() async throws {
             let commandName = RuntimeLinuxHelper._commandName
-            let log = RuntimeLinuxHelper.setupLogger(debug: debug, metadata: ["uuid": "\(uuid)"])
+            let logPath = logRoot.map { $0.appending("\(commandName)-\(uuid).log") }
+            let log = ServiceLogger.bootstrap(category: "RuntimeLinuxHelper", metadata: ["uuid": "\(uuid)"], debug: debug, logPath: logPath)
             log.info("starting helper", metadata: ["name": "\(commandName)"])
             defer {
                 log.info("stopping helper", metadata: ["name": "\(commandName)"])
@@ -117,7 +121,12 @@ extension RuntimeLinuxHelper {
                     _ = try await group.next()
                 }
             } catch {
-                log.error("helper failed", metadata: ["name": "\(commandName)", "error": "\(error)"])
+                log.error(
+                    "helper failed",
+                    metadata: [
+                        "name": "\(commandName)",
+                        "error": "\(error)",
+                    ])
                 try? await eventLoopGroup.shutdownGracefully()
                 RuntimeLinuxHelper.Start.exit(withError: error)
             }

Sources/Helpers/RuntimeLinux/RuntimeLinuxHelper.swift

@@ -15,10 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 import ArgumentParser
-import ContainerLog
 import ContainerVersion
-import Logging
-import OSLog
 
 @main
 struct RuntimeLinuxHelper: AsyncParsableCommand {
@@ -30,24 +27,4 @@ struct RuntimeLinuxHelper: AsyncParsableCommand {
             Start.self
         ]
     )
-
-    package static func setupLogger(debug: Bool, metadata: [String: Logging.Logger.Metadata.Value] = [:]) -> Logging.Logger {
-        LoggingSystem.bootstrap { label in
-            OSLogHandler(
-                label: label,
-                category: "RuntimeLinuxHelper"
-            )
-        }
-
-        var log = Logger(label: "com.apple.container")
-        if debug {
-            log.logLevel = .debug
-        }
-
-        for (key, val) in metadata {
-            log[metadataKey: key] = val
-        }
-
-        return log
-    }
 }

Sources/Services/ContainerAPIService/Client/ClientHealthCheck.swift

@@ -17,6 +17,7 @@
 import ContainerXPC
 import ContainerizationError
 import Foundation
+import SystemPackage
 
 public enum ClientHealthCheck {
     static let serviceIdentifier = "com.apple.container.apiserver"
@@ -37,6 +38,7 @@ extension ClientHealthCheck {
         guard let installRootValue = reply.string(key: .installRoot), let installRoot = URL(string: installRootValue) else {
             throw ContainerizationError(.internalError, message: "failed to decode installRoot in health check")
         }
+        let logRoot = reply.string(key: .logRoot).map { FilePath($0) }
         guard let apiServerVersion = reply.string(key: .apiServerVersion) else {
             throw ContainerizationError(.internalError, message: "failed to decode apiServerVersion in health check")
         }
@@ -52,6 +54,7 @@ extension ClientHealthCheck {
         return .init(
             appRoot: appRoot,
             installRoot: installRoot,
+            logRoot: logRoot,
             apiServerVersion: apiServerVersion,
             apiServerCommit: apiServerCommit,
             apiServerBuild: apiServerBuild,

Sources/Services/ContainerAPIService/Client/SystemHealth.swift

@@ -15,6 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 import Foundation
+import SystemPackage
 
 /// Snapshot of the health of container services and resources
 public struct SystemHealth: Sendable, Codable {
@@ -24,6 +25,9 @@ public struct SystemHealth: Sendable, Codable {
     /// The full pathname of the application install root.
     public let installRoot: URL
 
+    /// The full pathname of the application install root.
+    public let logRoot: FilePath?
+
     /// The release version of the container services.
     public let apiServerVersion: String
 

Sources/Services/ContainerAPIService/Client/XPC+.swift

@@ -61,6 +61,7 @@ public enum XPCKeys: String {
     case ping
     case appRoot
     case installRoot
+    case logRoot
     case apiServerVersion
     case apiServerCommit
     case apiServerBuild

Sources/Services/ContainerAPIService/Server/Containers/ContainersService.swift

@@ -119,7 +119,12 @@ public actor ContainersService {
                 }
             } catch {
                 try? FileManager.default.removeItem(at: dir)
-                log.warning("failed to load container", metadata: ["path": "\(dir.path)", "error": "\(error)"])
+                log.warning(
+                    "failed to load container",
+                    metadata: [
+                        "path": "\(dir.path)",
+                        "error": "\(error)",
+                    ])
             }
         }
         return results
@@ -546,7 +551,12 @@ public actor ContainersService {
                 let waitFunc: ExitMonitor.WaitHandler = {
                     log.info("registering container with exit monitor")
                     let code = try await client.wait(id)
-                    log.info("container finished in exit monitor", metadata: ["id": "\(id)", "rc": "\(code)"])
+                    log.info(
+                        "container finished in exit monitor",
+                        metadata: [
+                            "id": "\(id)",
+                            "rc": "\(code)",
+                        ])
 
                     return code
                 }
@@ -882,7 +892,12 @@ public actor ContainersService {
 
     private func handleContainerExit(id: String, code: ExitStatus?, context: AsyncLock.Context) async throws {
         if let code {
-            self.log.info("handling container exit", metadata: ["id": "\(id)", "rc": "\(code)"])
+            self.log.info(
+                "handling container exit",
+                metadata: [
+                    "id": "\(id)",
+                    "rc": "\(code)",
+                ])
         }
 
         var state: ContainerState
@@ -916,7 +931,12 @@ public actor ContainersService {
             do {
                 try await client.shutdown()
             } catch {
-                self.log.error("failed to shutdown sandbox service", metadata: ["id": "\(id)", "error": "\(error)"])
+                self.log.error(
+                    "failed to shutdown sandbox service",
+                    metadata: [
+                        "id": "\(id)",
+                        "error": "\(error)",
+                    ])
             }
         }
 
@@ -927,7 +947,12 @@ public actor ContainersService {
             try ServiceManager.deregister(fullServiceLabel: label)
             self.log.info("deregistered sandbox service", metadata: ["id": "\(id)"])
         } catch {
-            self.log.error("failed to deregister sandbox service", metadata: ["id": "\(id)", "error": "\(error)"])
+            self.log.error(
+                "failed to deregister sandbox service",
+                metadata: [
+                    "id": "\(id)",
+                    "error": "\(error)",
+                ])
         }
 
         // Best effort deallocate network attachments for the container. Don't throw on
@@ -999,7 +1024,12 @@ public actor ContainersService {
         do {
             config = try bundle.configuration
         } catch {
-            self.log.warning("failed to read bundle configuration during cleanup for container", metadata: ["id": "\(id)", "error": "\(error)"])
+            self.log.warning(
+                "failed to read bundle configuration during cleanup for container",
+                metadata: [
+                    "id": "\(id)",
+                    "error": "\(error)",
+                ])
         }
 
         // Only try to deregister service if we have a valid config
@@ -1017,7 +1047,12 @@ public actor ContainersService {
         do {
             try bundle.delete()
         } catch {
-            self.log.warning("failed to delete bundle for container", metadata: ["id": "\(id)", "error": "\(error)"])
+            self.log.warning(
+                "failed to delete bundle for container",
+                metadata: [
+                    "id": "\(id)",
+                    "error": "\(error)",
+                ])
         }
 
         self.containers.removeValue(forKey: id)

Sources/Services/ContainerAPIService/Server/HealthCheck/HealthCheckHarness.swift

@@ -21,15 +21,18 @@ import ContainerXPC
 import Containerization
 import Foundation
 import Logging
+import SystemPackage
 
 public actor HealthCheckHarness {
     private let appRoot: URL
     private let installRoot: URL
+    private let logRoot: FilePath?
     private let log: Logger
 
-    public init(appRoot: URL, installRoot: URL, log: Logger) {
+    public init(appRoot: URL, installRoot: URL, logRoot: FilePath?, log: Logger) {
         self.appRoot = appRoot
         self.installRoot = installRoot
+        self.logRoot = logRoot
         self.log = log
     }
 
@@ -38,6 +41,9 @@ public actor HealthCheckHarness {
         let reply = message.reply()
         reply.set(key: .appRoot, value: appRoot.absoluteString)
         reply.set(key: .installRoot, value: installRoot.absoluteString)
+        if let logRoot {
+            reply.set(key: .logRoot, value: logRoot.string)
+        }
         reply.set(key: .apiServerVersion, value: ReleaseVersion.singleLine(appName: "container-apiserver"))
         reply.set(key: .apiServerCommit, value: get_git_commit().map { String(cString: $0) } ?? "unspecified")
         // Extra optional fields for richer client display

Sources/Services/ContainerAPIService/Server/Volumes/VolumesService.swift

@@ -337,7 +337,13 @@ public actor VolumesService {
 
         try await store.create(volume)
 
-        log.info("created volume", metadata: ["name": "\(name)", "driver": "\(driver)", "isAnonymous": "\(volume.isAnonymous)"])
+        log.info(
+            "created volume",
+            metadata: [
+                "name": "\(name)",
+                "driver": "\(driver)",
+                "isAnonymous": "\(volume.isAnonymous)",
+            ])
         return volume
     }