runtime

Documentation

Overview

Package runtime wires reload and debug controls onto the agent: the Manager holds the current config, re-reads the YAML on SIGHUP, applies the hot-reloadable fields, and serves /debug.

A field is HOT if changing it rebinds no resource — the logging level plus everything config.Tunables projects. Everything else is LOAD-TIME: listen addresses, paths, log format, and the Neutron/Kafka connection sections. A load-time change in the YAML is warned about and ignored. Pinning is a one-shot boot action, so both bpf knobs are load-time.

docs/operations/runtime.md

Index

• type Manager
  • func New(configPath string, initial config.Config, log *logging.Handle) *Manager
  • func (m *Manager) Current() config.Config
  • func (m *Manager) DebugHandler() http.Handler
  • func (m *Manager) InstallSIGHUP(ctx context.Context)
  • func (m *Manager) Reload() error
  • func (m *Manager) SetMetrics(mx *Metrics)
  • func (m *Manager) SetOnReload(fn func())
  • func (m *Manager) SetTunables(s *tunables.Store)
• type Metrics
  • func NewMetrics() *Metrics
  • func (m *Metrics) Collectors() []prometheus.Collector
  • func (m *Metrics) RecordReload(result string)

Types

type Manager

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

Manager owns the agent's runtime configuration state. Construct one in main after config.Load and logging.Init, then call Manager.InstallSIGHUP and mount Manager.DebugHandler on the HTTP server.

func New

func New(configPath string, initial config.Config, log *logging.Handle) *Manager

New creates a Manager seeded with the initial config snapshot. The configPath is the YAML file location; an empty string disables SIGHUP reload while keeping the /debug HTTP endpoints functional.

func (*Manager) Current

func (m *Manager) Current() config.Config

Current returns a snapshot of the most recently applied configuration. Safe for concurrent callers.

func (*Manager) DebugHandler

func (m *Manager) DebugHandler() http.Handler

DebugHandler returns the /debug handler: GET /debug/config (secrets redacted) and PUT /debug/log-level. Mount alongside /metrics.

The endpoints are intentionally UNAUTHENTICATED and the default listen address is all-interfaces. Secrets never appear in responses, but /debug also exposes pprof and runtime tuning — on an untrusted network, bind to localhost or firewall the port.

func (*Manager) InstallSIGHUP

func (m *Manager) InstallSIGHUP(ctx context.Context)

InstallSIGHUP installs a handler that calls Manager.Reload on each SIGHUP. The goroutine stops when ctx is cancelled. Safe to call once per process; not concurrency-safe with itself.

func (*Manager) Reload

func (m *Manager) Reload() error

Reload reads the YAML file and applies hot-reloadable fields. Load-time fields whose YAML value differs from the running value are logged as warnings but not applied; restart is required for those.

Returns an error if the YAML cannot be read or fails validation. The active configuration is left unchanged in that case.

func (*Manager) SetMetrics

func (m *Manager) SetMetrics(mx *Metrics)

SetMetrics wires the reload-outcome counter. Call once during boot.

func (*Manager) SetOnReload

func (m *Manager) SetOnReload(fn func())

SetOnReload wires a hook run after every successful reload — the agent passes the reconciler's Kick so a hot reconcile-interval change (or any operator edit) applies at the NEXT reconcile within seconds, not after the running ticker's current period elapses (which, at a large old interval, would delay it by that whole period). Call once during boot, before Manager.InstallSIGHUP; nil leaves reload hook-free.

func (*Manager) SetTunables

func (m *Manager) SetTunables(s *tunables.Store)

SetTunables wires the shared hot-knob store SIGHUP reloads swap. Call once during boot, before Manager.InstallSIGHUP.

type Metrics

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

Metrics is the runtime subsystem's instrument bundle: reload outcomes, so a failed SIGHUP (malformed YAML kept the old config running) is observable instead of silent. Registered centrally by the agent like every per-package bundle.

func NewMetrics

func NewMetrics() *Metrics

NewMetrics constructs the bundle and pre-seeds every result label so the series exist before the first reload.

func (*Metrics) Collectors

func (m *Metrics) Collectors() []prometheus.Collector

Collectors returns the bundle's instruments for central registration.

func (*Metrics) RecordReload

func (m *Metrics) RecordReload(result string)

RecordReload counts one reload outcome.