createrepo_go

createrepo_go is a pure-Go toolkit for creating, reading, modifying, and merging RPM repository metadata. It provides command-line tools compatible with the familiar createrepo_c, modifyrepo_c, mergerepo_c, and sqliterepo_c workflows, plus a Go package for embedding repository metadata operations in other applications.

The Go module path is:

github.com/define42/createrepo_go

Features

• Generate repodata/repomd.xml with primary, filelists, and other metadata from RPM packages.
• Preserve or add extra repository metadata such as comps, modules, and updateinfo records.
• Generate yum-compatible SQLite metadata databases.
• Merge multiple repositories into one output repository.
• Load local or HTTP(S) repository metadata from Go code.
• Read and write common metadata compression formats: gz, bz2, xz, zstd, and zck.
• Generate optional filelists-ext and delta RPM metadata.

Requirements

• Go 1.24 or newer.

No C library bindings are required.

Build

From the repository root:

go build ./...

To install all command-line tools into your configured Go binary directory:

go install ./cmd/...

This installs:

• createrepo_c
• modifyrepo_c
• mergerepo_c
• sqliterepo_c

Command-Line Usage

Create repository metadata for a directory of RPMs:

createrepo_c /srv/repo

Write metadata to a separate output directory:

createrepo_c --outputdir /srv/repo-out /srv/rpms

Generate SQLite metadata along with XML metadata:

createrepo_c --database /srv/repo

Use a specific metadata compression format:

createrepo_c --compress-type gz /srv/repo
createrepo_c --zck /srv/repo

Update an existing repository while preserving additional metadata:

createrepo_c --update /srv/repo

Add a comps/group metadata file:

createrepo_c --groupfile comps.xml /srv/repo

Add or replace additional metadata in an existing repodata directory:

modifyrepo_c --mdtype modules modules.yaml /srv/repo/repodata

Remove an additional metadata record:

modifyrepo_c --remove modules /srv/repo/repodata

Merge repositories:

mergerepo_c --repo /srv/repo-a --repo /srv/repo-b --outputdir /srv/merged

Generate SQLite metadata for an existing repository:

sqliterepo_c /srv/repo

Read packages in parallel and cache checksums between runs:

createrepo_c --workers 8 --cachedir /var/cache/createrepo /srv/repo

When updating a repository, keep a few superseded metadata versions instead of deleting them all:

createrepo_c --update --retain-old-md 2 /srv/repo

Generate metadata for split media (one repository spanning several directories); package locations are prefixed with each volume's directory name:

createrepo_c --split --outputdir /srv/repo disc1 disc2 disc3

Merge repositories, choosing how packages that share a name and architecture are resolved (repo keeps the first repo's package, ts the newest build, nvr the highest version):

mergerepo_c --method nvr --repo /srv/repo-a --repo /srv/repo-b --outputdir /srv/merged

Merge in Koji mode, which keeps every package version and records each package's origin repository in pkgorigins metadata:

mergerepo_c --koji --repo /srv/repo-a --repo /srv/repo-b --outputdir /srv/merged

Skip unreadable packages and report a non-zero exit status, override a stale lock, or prune old metadata by age:

createrepo_c --error-exit-val --ignore-lock --retain-old-md-by-age 14d /srv/repo

Each command supports --version. The following createrepo_c flags are implemented: --workers, --cachedir, --skip-stat, --retain-old-md, --retain-old-md-by-age, --split, --recycle-pkglist, --error-exit-val, and --ignore-lock; and for mergerepo_c: --method, --koji, --pkgorigins, --blocked, --all, --arch-expand, --nogroups, --noupdateinfo, and --verbose.

--retain-old-md-by-age accepts an age such as 30 (seconds), 45s, 10m, 24h, 7d, or 2w. A few highly tool-specific flags remain accepted but ignored (--noarch-repo and --simple for mergerepo_c, and --zck-dict-dir for modifyrepo_c) so existing command lines keep working.

Go API

Import the public package:

import "github.com/define42/createrepo_go/pkg/createrepo"

Create repository metadata:

err := createrepo.Create(ctx, createrepo.Options{
	Directory:   "/srv/repo",
	Database:    true,
	Compression: createrepo.CompressionZstd,
	Checksum:    createrepo.ChecksumSHA256,
})

Load repository metadata:

repo, err := createrepo.LoadMetadata(ctx, "https://example.com/repo/", createrepo.LoadOptions{
	VerifyChecksums: true,
})
if err != nil {
	return err
}

for _, pkg := range repo.Packages {
	fmt.Println(pkg.Name, pkg.Version, pkg.Arch)
}

Modify an existing repodata directory:

err := createrepo.Modify(ctx, createrepo.ModifyOptions{
	MetadataPath: "/tmp/modules.yaml",
	RepodataDir:  "/srv/repo/repodata",
	MetadataType: "modules",
	Compress:     true,
	Compression:  createrepo.CompressionZstd,
})

Supported Metadata

The package can parse and emit the standard package metadata files:

• primary.xml
• filelists.xml
• filelists-ext.xml
• other.xml
• repomd.xml
• updateinfo.xml

Additional metadata records are preserved through create/update flows when requested.

Development

Run the test suite with:

go test ./...

Useful package layout:

• cmd/ contains the command-line entrypoints.
• internal/cli/ contains flag parsing and command dispatch.
• pkg/createrepo/ contains the public Go API and metadata implementation.
• tests/testdata/ contains RPMs and repository fixtures used by tests.

License

This project is distributed under the GNU General Public License version 2. See LICENSE for the full license text.