go-facter — Puppet's Facter system-inventory engine in pure Go, no cgo

go-facter is a pure-Go (no cgo) reimplementation of Facter, Puppet's system-inventory engine. It discovers structured facts about the host — os, kernel, networking, processors, memory, filesystems, virtual, system_uptime, identity and more — and exposes them through a small, stable API designed to be bound onto Ruby's Facter interface (Facter.value, Facter[], Facter.add, Facter.to_hash). Fact names and structure follow Facter's schema — the aggregate facts with the flat legacy aliases (operatingsystem, osfamily, ipaddress) alongside — so it is a drop-in for Puppet manifests that reference either shape. Every OS probe runs through an injectable seam, so the per-OS collectors and their error branches are covered deterministically — 100% coverage, CI green on Linux, macOS and Windows across 6 arches. It imports only the Go standard library.

Resolver framework ready

Lazy, per-run-cached facts with a dotted-path Value query, ToHash aggregate, and Add / AddFunc custom-fact registration — the stable surface a Ruby binding maps onto Facter.value / Facter[] / Facter.add / Facter.to_hash.

OS, kernel & identity ready

os (name/family/release/distro, os.macosx on Darwin, architecture) from /etc/os-release, sw_vers and the Windows version banner; kernel*; identity (user/group/uid/gid/privileged); timezone; path; facterversion.

Networking ready

networking with hostname / fqdn / domain and a per-interface map — ip/ip6/mac/mtu/netmask/network plus the bindings / bindings6 arrays and the elected primary — mirrored to the legacy ipaddress / macaddress / interfaces aliases.

Hardware & storage ready

processors (count/physicalcount/models/isa), memory (system + swap, bytes and human sizes), mountpoints, filesystems and disks — parsed from /proc, sysctl / vm_stat, df and /sys/block, skipped gracefully where a platform can’t provide one.

Virtualization & uptime ready

virtual / is_virtual — hypervisor detection via DMI and the CPU hypervisor flag, container detection via docker/podman markers and cgroups — plus system_uptime and its uptime* aliases.

DMI, SSH, security & cloud ready

Facter 4 parity facts: dmi (bios / board / chassis / product, with the bios_* / productname / serialnumber / uuid aliases), ssh host keys with pure-Go SSHFP fingerprints, selinux, load_averages, cloud / ec2_metadata (bounded, non-blocking probe), ruby, fips_enabled, aio_agent_version, augeasversion.

Custom & external facts ready

In-process custom facts through the Go registration API, and out-of-process external facts from facts.d directories — JSON, YAML and key=value .txt, plus executable facts. This is the seam the Ruby custom-fact DSL binds onto.

Ruby surface planned

Downstream, not part of this engine module: the sibling go-ruby-facter binds Ruby’s Facter API (Facter.value / [] / add / to_hash, the custom-fact DSL) onto this engine so Puppet manifests and Ruby code under rbgo can resolve facts.

ready capability complete (exit criteria met, nothing material left)
active in progress (substantial work shipped, not yet finished)
planned not started yet (or downstream by design)

The engine layer of the go-facter org: a stable Go API a Ruby binding maps directly onto Facter.value / Facter.add / Facter.to_hash, with the facter CLI as a thin consumer. Faithful to Facter's fact names and structure, dependency-free (standard library only), and built so Puppet manifests and Ruby code under the sibling org github.com/go-embedded-ruby can resolve facts.