Image list: skip unreadable entries

Author: Hokila

Sources/ContainerCommands/Image/ImageList.swift

@@ -63,7 +63,16 @@ extension Application {
                 return
             }
 
-            let resources = try await Self.buildResources(images: images, containerSystemConfig: containerSystemConfig)
+            let resources = await Self.buildResources(
+                images: images,
+                containerSystemConfig: containerSystemConfig,
+                onError: { image, error in
+                    log.warning(
+                        "skipping unreadable image",
+                        metadata: ["image": "\(image.reference)", "error": "\(error)"]
+                    )
+                }
+            )
 
             try Output.render(payload: resources, format: format) {
                 if verbose {
@@ -81,14 +90,34 @@ extension Application {
 
         /// Builds the resource for each image, denormalizing the reference so the
         /// display name omits the default registry.
-        private static func buildResources(images: [ClientImage], containerSystemConfig: ContainerSystemConfig) async throws -> [ImageResource] {
-            var resources: [ImageResource] = []
-            for image in images {
-                resources.append(
+        private static func buildResources(
+            images: [ClientImage],
+            containerSystemConfig: ContainerSystemConfig,
+            onError: (ClientImage, any Error) -> Void
+        ) async -> [ImageResource] {
+            await collectReadableValues(
+                from: images,
+                resolve: { image in
                     try await image.toImageResource(containerSystemConfig: containerSystemConfig)
-                )
+                },
+                onError: onError
+            )
+        }
+
+        static func collectReadableValues<Input, Value>(
+            from inputs: [Input],
+            resolve: (Input) async throws -> Value,
+            onError: (Input, any Error) -> Void
+        ) async -> [Value] {
+            var values: [Value] = []
+            for input in inputs {
+                do {
+                    values.append(try await resolve(input))
+                } catch {
+                    onError(input, error)
+                }
             }
-            return resources
+            return values
         }
     }
 }

Tests/ContainerCommandsTests/ImageListTests.swift

@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+// 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 Testing
+
+@testable import ContainerCommands
+
+struct ImageListTests {
+    private enum TestError: Error {
+        case unreadable
+    }
+
+    @Test
+    func unreadableEntryDoesNotPreventOtherEntriesFromResolving() async {
+        let inputs = ["healthy-one", "unreadable", "healthy-two"]
+        var failures: [String] = []
+        var failureDescriptions: [String] = []
+
+        let values = await Application.ImageList.collectReadableValues(
+            from: inputs,
+            resolve: { input in
+                if input == "unreadable" {
+                    throw TestError.unreadable
+                }
+                return input.uppercased()
+            },
+            onError: { input, error in
+                failures.append(input)
+                failureDescriptions.append("\(error)")
+            }
+        )
+
+        #expect(values == ["HEALTHY-ONE", "HEALTHY-TWO"])
+        #expect(failures == ["unreadable"])
+        #expect(failureDescriptions == ["unreadable"])
+    }
+}