Supported platforms

routerd targets one platform fully today and exposes groundwork for two more. The matrix is intentionally explicit so operators do not assume parity that the code does not yet provide.

Tier 1 — Ubuntu (and other Debian-family Linux)

• Full source-install layout under /usr/local.
• systemd unit at contrib/systemd/routerd.service.
• Installed and tested in CI. All currently implemented resource kinds (interface aliases, IPv4 static/DHCP, dnsmasq DHCP/DHCPv6/RA, IPv6 PD through systemd-networkd drop-ins, conditional DNS forwarding, PPPoE, DS-Lite, IPv4 source NAT through nftables, IPv4 policy routing, IPv4 default-route policy with health checks, reverse-path filters, MTU propagation, default-deny home-router firewall, sysctl, hostname, systemd-timesyncd, log sinks) work end-to-end.

Tier 2 — NixOS (groundwork)

• The repository-root flake builds the same Go binaries via buildGoModule, ships a NixOS module from contrib/nix/ that wires routerd into the systemd unit graph, and exposes a development shell.
• The NixOS module does not depend on netplan. Today, NixOS configurations should either observe externally managed interfaces or use Linux primitives that are already available on the host. Ubuntu's netplan renderer remains available for Ubuntu, but it is not a NixOS runtime dependency.
• Persistent NixOS settings are produced as Nix and applied with nixos-rebuild switch, not by having the daemon rewrite /etc configuration files. The flow is routerd render nixos producing routerd-generated.nix, a small configuration.nix importing it, then routerd serve handling non-persistent runtime decisions. The lab sample examples/nixos-router02-configuration.nix shows the hand-written side of this split.
• The first NixOS renderer emits host settings, dependency packages, and basic systemd-networkd .network declarations. More resource kinds still need Nix-native persistent rendering.

Tier 2 — FreeBSD (groundwork)

• pkg/platform declares FreeBSD defaults and feature flags. Cross- compiling cmd/routerd and cmd/routerctl for GOOS=freebsd succeeds.
• An rc.d script at contrib/freebsd/routerd is installed via make install-rc-freebsd (selected automatically by make install-service when uname -s is FreeBSD).
• Not yet implemented for FreeBSD:
  • pf renderer to replace nftables for source NAT and firewall.
  • rc.conf / ifconfig-based interface renderer to replace netplan and systemd-networkd.
  • mpd5 or native FreeBSD PPPoE wiring (Linux uses pppd / rp-pppoe).
  • dnsmasq orchestration via service instead of systemctl.
  • IPv6 prefix delegation via rtsold / rtadvd instead of systemd-networkd.

Until those land, routerd reconcile on FreeBSD will validate, plan, and dry-run, but will refuse or no-op for resource kinds that depend on Linux-only host integrations. Use routerd validate and routerd plan --dry-run to test configurations on FreeBSD today.

How the platform is selected

pkg/platform resolves OS-specific defaults at compile time using Go build tags. Renderers and the reconciler should consult platform.Current() rather than runtime.GOOS. New OS-specific behavior should be added in three places:

1. A new platform_<os>.go with build tags returning Defaults and Features.
2. A renderer guarded by platform.Features.HasX (or a build tag if the dependency would not even compile).
3. A contrib/<os>/ directory with the service-manager integration.

Non-goals (for now)

• Windows and macOS targets.
• Proprietary embedded router platforms.
• Containerized deployments. routerd manipulates host network state and is expected to run on the router itself.