Add LinuxContainer block I/O resources

Author: chrisgeo

Sources/Containerization/LinuxContainer.swift

@@ -56,6 +56,8 @@ public final class LinuxContainer: Container, Sendable {
         public var cpus: Int = 4
         /// The memory in bytes to give to the container.
         public var memoryInBytes: UInt64 = 1024.mib()
+        /// Optional block I/O resource limits for the container cgroup.
+        public var blockIO: LinuxBlockIO?
         /// The hostname for the container.
         public var hostname: String?
         /// The system control options for the container.
@@ -94,6 +96,7 @@ public final class LinuxContainer: Container, Sendable {
             process: LinuxProcessConfiguration,
             cpus: Int = 4,
             memoryInBytes: UInt64 = 1024.mib(),
+            blockIO: LinuxBlockIO? = nil,
             hostname: String? = nil,
             sysctl: [String: String] = [:],
             interfaces: [any Interface] = [],
@@ -111,6 +114,7 @@ public final class LinuxContainer: Container, Sendable {
             self.process = process
             self.cpus = cpus
             self.memoryInBytes = memoryInBytes
+            self.blockIO = blockIO
             self.hostname = hostname
             self.sysctl = sysctl
             self.interfaces = interfaces
@@ -374,7 +378,7 @@ public final class LinuxContainer: Container, Sendable {
         )
     }
 
-    private func generateRuntimeSpec() -> Spec {
+    func generateRuntimeSpec() -> Spec {
         var spec = Self.createDefaultRuntimeSpec(id)
 
         // Process toggles.
@@ -409,7 +413,8 @@ public final class LinuxContainer: Container, Sendable {
             cpu: LinuxCPU(
                 quota: Int64(config.cpus * 100_000),
                 period: 100_000
-            )
+            ),
+            blockIO: config.blockIO
         )
 
         spec.linux?.namespaces = [

Tests/ContainerizationTests/LinuxContainerTests.swift

@@ -66,4 +66,53 @@ struct LinuxContainerTests {
 
         #expect(process.arguments == ["/bin/sh", "-c", "echo 'hello'", "&&", "sleep 10"])
     }
+
+    @Test func runtimeSpecIncludesConfiguredBlockIO() throws {
+        let blockIO = LinuxBlockIO(
+            weight: 500,
+            leafWeight: 300,
+            weightDevice: [
+                LinuxWeightDevice(major: 8, minor: 0, weight: 700, leafWeight: 400)
+            ],
+            throttleReadBpsDevice: [
+                LinuxThrottleDevice(major: 8, minor: 16, rate: 1_048_576)
+            ],
+            throttleWriteBpsDevice: [
+                LinuxThrottleDevice(major: 8, minor: 32, rate: 2_097_152)
+            ],
+            throttleReadIOPSDevice: [
+                LinuxThrottleDevice(major: 8, minor: 48, rate: 1_000)
+            ],
+            throttleWriteIOPSDevice: [
+                LinuxThrottleDevice(major: 8, minor: 64, rate: 2_000)
+            ]
+        )
+
+        let container = try LinuxContainer(
+            "blkio-test",
+            rootfs: .block(format: "ext4", source: "/tmp/rootfs.img", destination: "/"),
+            vmm: StubVirtualMachineManager(),
+            configuration: .init(process: .init(), blockIO: blockIO)
+        )
+
+        let resources = try #require(container.generateRuntimeSpec().linux?.resources)
+        let specBlockIO = try #require(resources.blockIO)
+
+        #expect(specBlockIO.weight == 500)
+        #expect(specBlockIO.leafWeight == 300)
+        #expect(specBlockIO.weightDevice.first?.major == 8)
+        #expect(specBlockIO.weightDevice.first?.minor == 0)
+        #expect(specBlockIO.weightDevice.first?.weight == 700)
+        #expect(specBlockIO.weightDevice.first?.leafWeight == 400)
+        #expect(specBlockIO.throttleReadBpsDevice.first?.rate == 1_048_576)
+        #expect(specBlockIO.throttleWriteBpsDevice.first?.rate == 2_097_152)
+        #expect(specBlockIO.throttleReadIOPSDevice.first?.rate == 1_000)
+        #expect(specBlockIO.throttleWriteIOPSDevice.first?.rate == 2_000)
+    }
+}
+
+private struct StubVirtualMachineManager: VirtualMachineManager {
+    func create(config: some VMCreationConfig) async throws -> any VirtualMachineInstance {
+        fatalError("StubVirtualMachineManager.create should not be called by LinuxContainerTests")
+    }
 }