Struct BuildSkeleton 

pub struct BuildSkeleton {
    pub parsed_dockerfile: Dockerfile,
    pub base_layers: Vec<LayerRef>,
    pub base_manifest: BaseImageManifest,
    pub working_layer_chain_dir: PathBuf,
    pub working_chain: Vec<WindowsLayerEntry>,
    pub image_config: OciImageConfig,
    pub instruction_log: Vec<ExecutedInstruction>,
    pub provisioned_toolchain_language: Option<String>,
}

Output of WindowsBuilder::build_skeleton — the parsed Dockerfile plus the materialised base layer chain plus the resolved base manifest.

Consumed by Phase 4 follow-up tasks:

• 4.B (RUN, this task) iterates parsed_dockerfile.stages[0].instructions and for each Instruction::Run spawns an HCS compute system attached to the working chain stored in working_chain, captures the diff via wclayer::export_layer, and appends a new LayerRef to base_layers plus a new WindowsLayerEntry to working_chain.
• 4.C (COPY/ADD) writes context files into the working scratch layer before the next 4.B commit.
• 4.D (manifest) emits the final OCI image with os: "windows", os.version from base_manifest, and the accumulated base_layers + post-4.B layers chain.
• 4.E (push) pipes the 4.D manifest into the registry client.

Fields

parsed_dockerfile: Dockerfile

Parsed Dockerfile — parsed_dockerfile.stages[0] is the single stage supported by the skeleton.

base_layers: Vec<LayerRef>

Base image layers in base-first order (matching OCI manifest order). Task 4.B appends post-RUN layers to the end of this vector.

base_manifest: BaseImageManifest

Manifest metadata from the resolved base image.

working_layer_chain_dir: PathBuf

On-disk path to the working layer chain root. On Windows this is the directory passed to [zlayer_agent::windows::unpacker::unpack_windows_image]; on other hosts this field is the <cache_dir>/<build_id>/unpacked/ path the skeleton would have used had the build proceeded. Each post-RUN read-only layer is staged as a subdirectory here.

working_chain: Vec<WindowsLayerEntry>

Materialised layers in base-first order. The HCS storage filter consumes the reversed (child-to-parent) view; helpers in this module do the reversal at the point of use. Populated on Windows by build_skeleton from the unpacker output and extended by each successful RUN step.

image_config: OciImageConfig

OCI image config accumulated by config-only Dockerfile instructions (WORKDIR / ENV / ENTRYPOINT / CMD / USER / EXPOSE / VOLUME / LABEL / SHELL / STOPSIGNAL / HEALTHCHECK / ONBUILD). Task 4.D serialises this into the image config blob.

instruction_log: Vec<ExecutedInstruction>

Per-instruction execution log in build order. The first entry is the FROM instruction (recorded by WindowsBuilder::build_skeleton); subsequent entries are appended by WindowsBuilder::execute_instruction in the order it is called. Task 4.D (WindowsBuilder::emit_image) consumes this to emit the OCI image config history array.

provisioned_toolchain_language: Option<String>

Provisioned toolchain language detected for this base image, e.g. "go", "node", "rust", "python", or None if the base does not carry a prebuilt language toolchain. Populated by WindowsBuilder::build_image_for_backend right after build_skeleton from [crate::windows_toolchain::detect_toolchain]. Threaded into the crate::buildah::DockerfileTranslator on each RUN so package-manager translation can skip system packages that the provisioned toolchain already supplies (e.g. dropping apt install nodejs when the image already ships a Node toolchain). None for everything that goes through WindowsBuilder::build_skeleton / WindowsBuilder::build_and_push — those paths predate the toolchain hook and stay on the translator’s default behaviour.

Trait Implementations

impl Debug for BuildSkeleton

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.