Add container system version with format yaml

Package.swift

@@ -57,6 +57,7 @@ let package = Package(
         .package(url: "https://github.com/grpc/grpc-swift.git", from: "1.26.0"),
         .package(url: "https://github.com/swift-server/async-http-client.git", from: "1.20.1"),
         .package(url: "https://github.com/swiftlang/swift-docc-plugin.git", from: "1.1.0"),
+        .package(url: "https://github.com/jpsim/Yams.git", from: "6.2.1"),
     ],
     targets: [
         .executableTarget(
@@ -79,6 +80,7 @@ let package = Package(
                 "ContainerBuild",
                 "ContainerLog",
                 "ContainerResource",
+                "Yams",
             ],
             path: "Tests/CLITests"
         ),
@@ -101,6 +103,7 @@ let package = Package(
                 "ContainerVersion",
                 "ContainerXPC",
                 "TerminalProgress",
+                "Yams",
             ],
             path: "Sources/ContainerCommands"
         ),

Sources/ContainerCommands/Application.swift

@@ -248,6 +248,7 @@ extension Application {
     public enum ListFormat: String, CaseIterable, ExpressibleByArgument {
         case json
         case table
+        case yaml
     }
 
     func isTranslated() throws -> Bool {

Sources/ContainerCommands/System/SystemVersion.swift

@@ -18,6 +18,7 @@ import ArgumentParser
 import ContainerAPIClient
 import ContainerVersion
 import Foundation
+import Yams
 
 extension Application {
     public struct SystemVersion: AsyncLoggableCommand {
@@ -63,6 +64,8 @@ extension Application {
                 printVersionTable(versions: versions)
             case .json:
                 try printVersionJSON(versions: versions)
+            case .yaml:
+                try printVersionYAML(versions: versions)
             }
         }
 
@@ -78,6 +81,11 @@ extension Application {
             let data = try JSONEncoder().encode(versions)
             print(String(data: data, encoding: .utf8) ?? "[]")
         }
+
+        private func printVersionYAML(versions: [VersionInfo]) throws {
+            let data = try YAMLEncoder().encode(versions)
+            print(data)
+        }
     }
 
     public struct VersionInfo: Codable {

Tests/CLITests/Subcommands/System/TestCLIVersion.swift

@@ -16,6 +16,7 @@
 
 import Foundation
 import Testing
+import Yams
 
 /// Tests for `container system version` output formats and build type detection.
 final class TestCLIVersion: CLITest {
@@ -26,7 +27,7 @@ final class TestCLIVersion: CLITest {
         let appName: String
     }
 
-    struct VersionJSON: Codable {
+    struct VersionOutput: Codable {
         let version: String
         let buildType: String
         let commit: String
@@ -68,7 +69,21 @@ final class TestCLIVersion: CLITest {
         #expect(status == 0, "system version --format json should succeed, stderr: \(err)")
         #expect(!out.isEmpty)
 
-        let decoded = try JSONDecoder().decode([VersionJSON].self, from: data)
+        let decoded = try JSONDecoder().decode([VersionOutput].self, from: data)
+        #expect(decoded[0].appName == "container")
+        #expect(!decoded[0].version.isEmpty)
+        #expect(!decoded[0].commit.isEmpty)
+
+        let expected = try expectedBuildType()
+        #expect(decoded[0].buildType == expected)
+    }
+
+    @Test func yamlFormat() throws {
+        let (data, out, err, status) = try run(arguments: ["system", "version", "--format", "yaml"])
+        #expect(status == 0, "system version --format yaml should succeed, stderr: \(err)")
+        #expect(!out.isEmpty)
+
+        let decoded = try YAMLDecoder().decode([VersionOutput].self, from: data)
         #expect(decoded[0].appName == "container")
         #expect(!decoded[0].version.isEmpty)
         #expect(!decoded[0].commit.isEmpty)
@@ -92,7 +107,7 @@ final class TestCLIVersion: CLITest {
         // Validate build type via JSON to avoid parsing table text loosely
         let (data, _, err, status) = try run(arguments: ["system", "version", "--format", "json"])
         #expect(status == 0, "version --format json should succeed, stderr: \(err)")
-        let decoded = try JSONDecoder().decode([VersionJSON].self, from: data)
+        let decoded = try JSONDecoder().decode([VersionOutput].self, from: data)
 
         let expected = try expectedBuildType()
         #expect(decoded[0].buildType == expected, "Expected build type \(expected) but got \(decoded[0].buildType)")

docs/command-reference.md

@@ -1033,7 +1033,7 @@ container system version [--format <format>]
 
 **Options**
 
-*   `--format <format>`: Output format (values: json, table; default: table)
+*   `--format <format>`: Output format (values: json, table, yaml; default: table)
 
 **Table Output**
 
@@ -1070,6 +1070,21 @@ Backward-compatible with previous CLI-only output. Top-level fields describe the
 }
 ```
 
+**YAML Output**
+
+Equivalent to the JSON output but in YAML format. Each entry in the array represents a component.
+
+```yaml
+- version: 1.2.3
+  buildType: debug
+  commit: abcdef1
+  appName: container
+- version: 1.2.3
+  buildType: release
+  commit: 1234abc
+  appName: container-apiserver
+```
+
 ### `container system logs`
 
 Displays logs from the container services. You can specify a time interval or follow new logs in real time.