Hyper.Img.OciLoader (Hyper v0.1.0)

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Builds an ext4 rootfs from an OCI image and hands it to Hyper.Img.create/2.

load/1 takes a registry reference (e.g. "docker.io/library/alpine:3.19") and:

  1. pulls it with skopeo, selecting the manifest entry matching this node's architecture, into a local OCI layout.
  2. flattens it with umoci unpack, which applies OCI whiteouts/opaque dirs correctly, yielding a merged rootfs directory.
  3. builds an ext4 image of that rootfs with mke2fs -d.
  4. hands the ext4 file to Hyper.Img.create/2, which content-addresses it, publishes it into the media store, and records it as a base image -- returning the img_id.

This module owns only the OCI-to-ext4 conversion; ingesting a prepared image file into the store and database is Hyper.Img's job.

Summary

Functions

load(ref)

Load ref into the store and DB. See the module doc. Label defaults to ref.

load(ref, opts)

Load ref. opts[:label] sets the human-readable images.label (defaults to ref).

test_system()

Verify the external tools the loader needs (skopeo, umoci, mke2fs) are resolvable on this host. Returns {:error, {:missing_tools, names}} listing any that are absent.

Functions

load(ref)

@spec load(String.t()) :: {:ok, Hyper.Img.id()} | {:error, term()}

Load ref into the store and DB. See the module doc. Label defaults to ref.

load(ref, opts)

@spec load(
  String.t(),
  keyword()
) :: {:ok, Hyper.Img.id()} | {:error, term()}

Load ref. opts[:label] sets the human-readable images.label (defaults to ref).

Returns {:error, {:missing_tools, names}} when the node lacks a required external tool (skopeo/umoci/mke2fs); the check runs up front so the load fails fast before the multi-minute pull.

test_system()

@spec test_system() :: :ok | {:error, term()}

Verify the external tools the loader needs (skopeo, umoci, mke2fs) are resolvable on this host. Returns {:error, {:missing_tools, names}} listing any that are absent.