oci-zig

OCI container library for Zig. Provides types, registry client, image building, and Containerfile parsing.

Modules

• spec - OCI specification types (image, runtime, distribution)
• registry - HTTP registry client with authentication and multi-platform resolution
• auth - Registry authentication
• layer - Tar layer extraction with gzip/zstd decompression and OCI whiteout handling
• cache - Content-addressable blob caching
• layout_writer - OCI image layout writer
• containerfile - Containerfile/Dockerfile parser
• image - Image reference parsing

Usage

Add to your build.zig.zon:

.dependencies = .{
    .oci = .{
        .url = "git+https://github.com/ananthb/oci-zig",
        .hash = "...",
    },
},

In build.zig:

const oci_dep = b.dependency("oci", .{});
exe.root_module.addImport("oci", oci_dep.module("oci"));

In your code:

const oci = @import("oci");

// Parse an image reference
var ref = try oci.image.ImageReference.parse("alpine:latest", allocator);

// Pull from a registry
var client = oci.registry.RegistryClient.init(allocator, "registry-1.docker.io");
defer client.deinit();
try client.ensureAuth("library/alpine");
const manifest = try client.fetchManifest("library/alpine", "latest", null);

// Parse a Containerfile
const cf = try oci.containerfile.Containerfile.parse(allocator, dockerfile_content);
defer cf.deinit(allocator);

// Write an OCI image layout
const digest = try oci.layout_writer.writeOciLayout(allocator, rootfs_dir, output_dir, image_config);

Development

nix develop    # enter devshell (zig, zls, pre-commit hooks)
zig build test # run tests
nix flake check # run all CI checks (test, fmt, build, pre-commit)

License

Licensed under the terms of the AGPL-3.0.