Warn user when a named volume is auto-created (apple#1108)

- Implemented the TODO at
  ContainerAPIService/Client/Utility.swift:358 — warn the
  user when a named volume is auto-created.
- This only triggers for named volumes (not anonymous
  ones), matching Docker's behavior of informing users
  about implicit resource creation.

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: poetryofcode

Sources/ContainerCommands/Container/ContainerCreate.swift

@@ -78,7 +78,8 @@ extension Application {
                 resource: resourceFlags,
                 registry: registryFlags,
                 imageFetch: imageFetchFlags,
-                progressUpdate: progress.handler
+                progressUpdate: progress.handler,
+                log: log
             )
 
             let options = ContainerCreateOptions(autoRemove: managementFlags.remove)

Sources/ContainerCommands/Container/ContainerRun.swift

@@ -103,7 +103,8 @@ extension Application {
                 resource: resourceFlags,
                 registry: registryFlags,
                 imageFetch: imageFetchFlags,
-                progressUpdate: progress.handler
+                progressUpdate: progress.handler,
+                log: log
             )
 
             progress.set(description: "Starting container")

Sources/Services/ContainerAPIService/Client/Utility.swift

@@ -21,6 +21,7 @@ import ContainerizationError
 import ContainerizationExtras
 import ContainerizationOCI
 import Foundation
+import Logging
 import TerminalProgress
 
 public struct Utility {
@@ -81,7 +82,8 @@ public struct Utility {
         resource: Flags.Resource,
         registry: Flags.Registry,
         imageFetch: Flags.ImageFetch,
-        progressUpdate: @escaping ProgressUpdateHandler
+        progressUpdate: @escaping ProgressUpdateHandler,
+        log: Logger
     ) async throws -> (ContainerConfiguration, Kernel) {
         var requestedPlatform = Parser.platform(os: management.os, arch: management.arch)
         // Prefer --platform
@@ -173,7 +175,7 @@ public struct Utility {
             case .filesystem(let fs):
                 resolvedMounts.append(fs)
             case .volume(let parsed):
-                let volume = try await getOrCreateVolume(parsed: parsed)
+                let volume = try await getOrCreateVolume(parsed: parsed, log: log)
                 let volumeMount = Filesystem.volume(
                     name: parsed.name,
                     format: volume.format,
@@ -343,17 +345,19 @@ public struct Utility {
 
     /// Gets an existing volume or creates it if it doesn't exist.
     /// Shows a warning for named volumes when auto-creating.
-    private static func getOrCreateVolume(parsed: ParsedVolume) async throws -> Volume {
+    private static func getOrCreateVolume(parsed: ParsedVolume, log: Logger) async throws -> Volume {
         let labels = parsed.isAnonymous ? [Volume.anonymousLabel: ""] : [:]
 
         let volume: Volume
+        var wasCreated = false
         do {
             volume = try await ClientVolume.create(
                 name: parsed.name,
                 driver: "local",
                 driverOpts: [:],
                 labels: labels
             )
+            wasCreated = true
         } catch let error as VolumeError {
             guard case .volumeAlreadyExists = error else {
                 throw error
@@ -368,7 +372,9 @@ public struct Utility {
             volume = try await ClientVolume.inspect(parsed.name)
         }
 
-        // TODO: Warn user if named volume was auto-created
+        if wasCreated && !parsed.isAnonymous {
+            log.warning("named volume was automatically created", metadata: ["volume": "\(parsed.name)"])
+        }
 
         return volume
     }