Add oom event to monitors

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

linux/runtime.go

@@ -56,7 +56,7 @@ func New(ic *plugin.InitContext) (interface{}, error) {
 		cfg.Runtime = defaultRuntime
 	}
 	c, cancel := context.WithCancel(ic.Context)
-	return &Runtime{
+	r := &Runtime{
 		root:          path,
 		remote:        !cfg.NoShim,
 		runtime:       cfg.Runtime,
@@ -64,7 +64,10 @@ func New(ic *plugin.InitContext) (interface{}, error) {
 		eventsContext: c,
 		eventsCancel:  cancel,
 		monitor:       ic.Monitor,
-	}, nil
+	}
+	// set the events output for a monitor if it generates events
+	ic.Monitor.Events(r.events)
+	return r, nil
 }
 
 type Runtime struct {

metrics/cgroups/cgroups.go

@@ -1,6 +1,8 @@
 package cgroups
 
 import (
+	"time"
+
 	"github.com/containerd/containerd"
 	"github.com/containerd/containerd/plugin"
 	"github.com/crosbymichael/cgroups"
@@ -39,6 +41,7 @@ type cgroupsMonitor struct {
 	collector *prometheus.Collector
 	oom       *prometheus.OOMCollector
 	context   context.Context
+	events    chan<- *containerd.Event
 }
 
 func (m *cgroupsMonitor) Monitor(c containerd.Container) error {
@@ -58,7 +61,7 @@ func (m *cgroupsMonitor) Monitor(c containerd.Container) error {
 	if err := m.collector.Add(id, cg); err != nil {
 		return err
 	}
-	return m.oom.Add(id, cg)
+	return m.oom.Add(id, cg, m.trigger)
 }
 
 func (m *cgroupsMonitor) Stop(c containerd.Container) error {
@@ -68,3 +71,15 @@ func (m *cgroupsMonitor) Stop(c containerd.Container) error {
 	m.collector.Remove(c.Info().ID)
 	return nil
 }
+
+func (m *cgroupsMonitor) Events(events chan<- *containerd.Event) {
+	m.events = events
+}
+
+func (m *cgroupsMonitor) trigger(id string, cg cgroups.Cgroup) {
+	m.events <- &containerd.Event{
+		Timestamp: time.Now(),
+		Type:      containerd.OOMEvent,
+		ID:        id,
+	}
+}

plugin/monitor.go

@@ -8,6 +8,8 @@ type ContainerMonitor interface {
 	Monitor(containerd.Container) error
 	// Stop stops and removes the provided container from the monitor
 	Stop(containerd.Container) error
+	// Events emits events from the monitor
+	Events(chan<- *containerd.Event)
 }
 
 func NewMultiContainerMonitor(monitors ...ContainerMonitor) ContainerMonitor {
@@ -31,6 +33,9 @@ func (mm *noopContainerMonitor) Stop(c containerd.Container) error {
 	return nil
 }
 
+func (mm *noopContainerMonitor) Events(events chan<- *containerd.Event) {
+}
+
 type multiContainerMonitor struct {
 	monitors []ContainerMonitor
 }
@@ -52,3 +57,9 @@ func (mm *multiContainerMonitor) Stop(c containerd.Container) error {
 	}
 	return nil
 }
+
+func (mm *multiContainerMonitor) Events(events chan<- *containerd.Event) {
+	for _, m := range mm.monitors {
+		m.Events(events)
+	}
+}