lifecycle

Documentation

Overview

Package lifecycle detects the discrete host lifecycle events the agent emits as the strong-delivery signal class: boot, unexpected_reboot, clean_shutdown, oom_kill and fs_readonly. It reads only unprivileged /proc files and persists two small 0600 files in the state directory: a state file (the last-seen boot_id and a periodically refreshed liveness timestamp) and a clean_shutdown marker written on SIGTERM. The marker is what makes the next boot a clean boot rather than an unexpected reboot.

Events are emitted into the shared event queue. On a crash there is no live send; the safety net is the exit spool plus the boot backfill: events queued here are spooled on exit and delivered after the next start.

Index

• type Detector
  • func New(fs platform.FS, clock platform.Clock, emitter Emitter, stateDir string) *Detector
  • func (d *Detector) Shutdown(context.Context)
  • func (d *Detector) Startup(context.Context)
  • func (d *Detector) Tick(context.Context)
• type Emitter

Types

type Detector

type Detector struct {
	// contains filtered or unexported fields
}

Detector holds the lifecycle detection state and the persistence paths.

func New

func New(fs platform.FS, clock platform.Clock, emitter Emitter, stateDir string) *Detector

New builds a Detector rooted at stateDir.

func (*Detector) Shutdown

func (d *Detector) Shutdown(context.Context)

Shutdown runs on SIGTERM: it emits clean_shutdown and persists the marker so the next boot is recognised as clean. It is best-effort and must not block.

func (*Detector) Startup

func (d *Detector) Startup(context.Context)

Startup runs once before the first report: it compares the current boot_id to the persisted one and emits boot or unexpected_reboot on a change, consumes the clean_shutdown marker, refreshes the persisted state, and seeds the oom and read-only-mount baselines so Tick reports only transitions.

func (*Detector) Tick

func (d *Detector) Tick(context.Context)

Tick runs each collect interval: it emits oom_kill on a positive vmstat delta and fs_readonly when a previously writable mount has flipped read-only, and refreshes the liveness timestamp at most once per flushEvery.

type Emitter

type Emitter interface {
	Emit(t wire.EventType, meta map[string]string)
}

Emitter raises a lifecycle event. It matches internal/event.Emitter without importing it, mirroring the buffer package.