Files
container/Sources/Containerization/Image/InitImage.swift
T
Danny Canter 6bc4bf5124 Source code documentation updates (#9)
This change adds documentation to quite a few existing public types that
didn't have a blurb before.

Additionally, this fixes a couple things that I think either didn't make
sense when going to document them:
- Rename ConnectionStream to VsockConnectionStream. This type only
functions for vsock connections.
- Deletes NsLock+Closure. This was not used anywhere.
- Rename ContainerizationOCI/Config.swift to ImageConfig.swift.

Signed-off-by: Danny Canter <danny_canter@apple.com>
2025-06-05 16:16:18 -07:00

85 lines
4.2 KiB
Swift

//===----------------------------------------------------------------------===//
// Copyright © 2025 Apple Inc. and the containerization project authors. All rights reserved.
//
// 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 ContainerizationError
import ContainerizationOCI
import Foundation
/// Data representing the image to use as the root filesystem for a virtual machine.
/// Typically this image would contain the guest agent used to facilitate container
/// workloads, as well as any extras that may be useful to have in the guest.
public struct InitImage: Sendable {
public var name: String { image.reference }
let image: Image
public init(image: Image) {
self.image = image
}
}
extension InitImage {
/// Unpack the initial filesystem for the desired platform at a given path.
public func initBlock(at: URL, for platform: SystemPlatform) async throws -> Mount {
var fs = try await image.unpack(for: platform.ociPlatform(), at: at, blockSizeInBytes: 512.mib())
fs.options = ["ro"]
return fs
}
/// Create a new InitImage with the reference as the name.
/// The `rootfs` parameter must be a tar.gz file whose contents make up the filesystem for the image.
public static func create(
reference: String, rootfs: URL, platform: Platform,
labels: [String: String] = [:], imageStore: ImageStore, contentStore: ContentStore
) async throws -> InitImage {
let indexDescriptorStore = AsyncStore<Descriptor>()
try await contentStore.ingest { dir in
let writer = try ContentWriter(for: dir)
var result = try writer.create(from: rootfs)
let layerDescriptor = Descriptor(mediaType: ContainerizationOCI.MediaTypes.imageLayerGzip, digest: result.digest.digestString, size: result.size)
// TODO: compute and fill in the correct diffID for the above layer
// We currently put in the sha of the fully compressed layer, this needs to be replaced with
// the sha of the uncompressed layer.
let rootfsConfig = ContainerizationOCI.Rootfs(type: "layers", diffIDs: [result.digest.digestString])
let runtimeConfig = ContainerizationOCI.ImageConfig(labels: labels)
let imageConfig = ContainerizationOCI.Image(architecture: platform.architecture, os: platform.os, config: runtimeConfig, rootfs: rootfsConfig)
result = try writer.create(from: imageConfig)
let configDescriptor = Descriptor(mediaType: ContainerizationOCI.MediaTypes.imageConfig, digest: result.digest.digestString, size: result.size)
let manifest = Manifest(config: configDescriptor, layers: [layerDescriptor])
result = try writer.create(from: manifest)
let manifestDescriptor = Descriptor(mediaType: ContainerizationOCI.MediaTypes.imageManifest, digest: result.digest.digestString, size: result.size, platform: platform)
let index = ContainerizationOCI.Index(manifests: [manifestDescriptor])
result = try writer.create(from: index)
let indexDescriptor = Descriptor(mediaType: ContainerizationOCI.MediaTypes.index, digest: result.digest.digestString, size: result.size)
await indexDescriptorStore.set(indexDescriptor)
}
guard let indexDescriptor = await indexDescriptorStore.get() else {
throw ContainerizationError(.notFound, message: "image for \(reference) not found")
}
let description = Image.Description(reference: reference, descriptor: indexDescriptor)
let image = try await imageStore.create(description: description)
return InitImage(image: image)
}
}