First phase of splitting the daemon god-struct into focused services
with explicit ownership.
HostNetwork now owns everything host-networking: the TAP interface
pool (initializeTapPool / ensureTapPool / acquireTap / releaseTap /
createTap), bridge + socket dir setup, firecracker process primitives
(find/resolve/kill/wait/ensureSocketAccess/sendCtrlAltDel), DM
snapshot lifecycle, NAT rule enforcement, guest DNS server lifecycle
+ routing setup, and the vsock-agent readiness probe. That's 7 files
whose receivers flipped from *Daemon to *HostNetwork, plus a new
host_network.go that declares the struct, its hostNetworkDeps, and
the factored firecracker + DNS helpers that used to live in vm.go.
Daemon gives up the tapPool and vmDNS fields entirely; they're now
HostNetwork's business. Construction goes through newHostNetwork in
Daemon.Open with an explicit dependency bag (runner, logger, config,
layout, closing). A lazy-init hostNet() helper on Daemon supports
test literals that don't wire net explicitly — production always
populates it eagerly.
Signature tightenings where the old receiver reached into VM-service
state:
- ensureNAT(ctx, vm, enable) → ensureNAT(ctx, guestIP, tap, enable).
Callers resolve tap from the handle cache themselves.
- initializeTapPool(ctx) → initializeTapPool(usedTaps []string).
Daemon.Open enumerates VMs, collects taps from handles, hands the
slice in.
rebuildDNS stays on *Daemon as the orchestrator — it filters by
vm-alive (a VMService concern handles will move to in phase 4) then
calls HostNetwork.replaceDNS with the already-filtered map.
Capability hooks continue to take *Daemon; they now use it as a
facade to reach services (d.net.ensureNAT, d.hostNet().*). Planned
CapabilityHost interface extraction is orthogonal, left for later.
Tests: dns_routing_test.go + fastpath_test.go + nat_test.go +
snapshot_test.go + open_close_test.go were touched to construct
HostNetwork literals where they exercise its methods directly, or
route through d.hostNet() where they exercise the Daemon entry
points.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Thales Maciel
362009d747