moby/daemon/events.go

package daemon

import (
	"strings"
	"time"

	"github.com/docker/docker/container"
	daemonevents "github.com/docker/docker/daemon/events"
	"github.com/docker/engine-api/types/events"
	"github.com/docker/engine-api/types/filters"
	"github.com/docker/libnetwork"
)

// LogContainerEvent generates an event related to a container with only the default attributes.
func (daemon *Daemon) LogContainerEvent(container *container.Container, action string) {
	daemon.LogContainerEventWithAttributes(container, action, map[string]string{})
}

// LogContainerEventWithAttributes generates an event related to a container with specific given attributes.
func (daemon *Daemon) LogContainerEventWithAttributes(container *container.Container, action string, attributes map[string]string) {
	copyAttributes(attributes, container.Config.Labels)
	if container.Config.Image != "" {
		attributes["image"] = container.Config.Image
	}
	attributes["name"] = strings.TrimLeft(container.Name, "/")

	actor := events.Actor{
		ID:         container.ID,
		Attributes: attributes,
	}
	daemon.EventsService.Log(action, events.ContainerEventType, actor)
}

// LogImageEvent generates an event related to an image with only the default attributes.
func (daemon *Daemon) LogImageEvent(imageID, refName, action string) {
	daemon.LogImageEventWithAttributes(imageID, refName, action, map[string]string{})
}

// LogImageEventWithAttributes generates an event related to an image with specific given attributes.
func (daemon *Daemon) LogImageEventWithAttributes(imageID, refName, action string, attributes map[string]string) {
	img, err := daemon.GetImage(imageID)
	if err == nil && img.Config != nil {
		// image has not been removed yet.
		// it could be missing if the event is `delete`.
		copyAttributes(attributes, img.Config.Labels)
	}
	if refName != "" {
		attributes["name"] = refName
	}
	actor := events.Actor{
		ID:         imageID,
		Attributes: attributes,
	}

	daemon.EventsService.Log(action, events.ImageEventType, actor)
}

// LogVolumeEvent generates an event related to a volume.
func (daemon *Daemon) LogVolumeEvent(volumeID, action string, attributes map[string]string) {
	actor := events.Actor{
		ID:         volumeID,
		Attributes: attributes,
	}
	daemon.EventsService.Log(action, events.VolumeEventType, actor)
}

// LogNetworkEvent generates an event related to a network with only the default attributes.
func (daemon *Daemon) LogNetworkEvent(nw libnetwork.Network, action string) {
	daemon.LogNetworkEventWithAttributes(nw, action, map[string]string{})
}

// LogNetworkEventWithAttributes generates an event related to a network with specific given attributes.
func (daemon *Daemon) LogNetworkEventWithAttributes(nw libnetwork.Network, action string, attributes map[string]string) {
	attributes["name"] = nw.Name()
	attributes["type"] = nw.Type()
	actor := events.Actor{
		ID:         nw.ID(),
		Attributes: attributes,
	}
	daemon.EventsService.Log(action, events.NetworkEventType, actor)
}

// LogDaemonEventWithAttributes generates an event related to the daemon itself with specific given attributes.
func (daemon *Daemon) LogDaemonEventWithAttributes(action string, attributes map[string]string) {
	if daemon.EventsService != nil {
		if info, err := daemon.SystemInfo(); err == nil && info.Name != "" {
			attributes["name"] = info.Name
		}
		actor := events.Actor{
			ID:         daemon.ID,
			Attributes: attributes,
		}
		daemon.EventsService.Log(action, events.DaemonEventType, actor)
	}
}

// SubscribeToEvents returns the currently record of events, a channel to stream new events from, and a function to cancel the stream of events.
func (daemon *Daemon) SubscribeToEvents(since, until time.Time, filter filters.Args) ([]events.Message, chan interface{}) {
	ef := daemonevents.NewFilter(filter)
	return daemon.EventsService.SubscribeTopic(since, until, ef)
}

// UnsubscribeFromEvents stops the event subscription for a client by closing the
// channel where the daemon sends events to.
func (daemon *Daemon) UnsubscribeFromEvents(listener chan interface{}) {
	daemon.EventsService.Evict(listener)
}

// copyAttributes guarantees that labels are not mutated by event triggers.
func copyAttributes(attributes, labels map[string]string) {
	if labels == nil {
		return
	}
	for k, v := range labels {
		attributes[k] = v
	}
}