1
0
Fork 0
mirror of https://github.com/moby/moby.git synced 2022-11-09 12:21:53 -05:00
moby--moby/plugin/events.go
Brian Goff 72c3bcf2a5 Make plugin emit strongly typed, consumable events
Enables other subsystems to watch actions for a plugin(s).

This will be used specifically for implementing plugins on swarm where a
swarm controller needs to watch the state of a plugin.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
2017-07-06 14:26:06 -04:00

111 lines
2.8 KiB
Go

package plugin
import (
"fmt"
"reflect"
"github.com/docker/docker/api/types"
)
// Event is emitted for actions performed on the plugin manager
type Event interface {
matches(Event) bool
}
// EventCreate is an event which is emitted when a plugin is created
// This is either by pull or create from context.
//
// Use the `Interfaces` field to match only plugins that implement a specific
// interface.
// These are matched against using "or" logic.
// If no interfaces are listed, all are matched.
type EventCreate struct {
Interfaces map[string]bool
Plugin types.Plugin
}
func (e EventCreate) matches(observed Event) bool {
oe, ok := observed.(EventCreate)
if !ok {
return false
}
if len(e.Interfaces) == 0 {
return true
}
var ifaceMatch bool
for _, in := range oe.Plugin.Config.Interface.Types {
if e.Interfaces[in.Capability] {
ifaceMatch = true
break
}
}
return ifaceMatch
}
// EventRemove is an event which is emitted when a plugin is removed
// It maches on the passed in plugin's ID only.
type EventRemove struct {
Plugin types.Plugin
}
func (e EventRemove) matches(observed Event) bool {
oe, ok := observed.(EventRemove)
if !ok {
return false
}
return e.Plugin.ID == oe.Plugin.ID
}
// EventDisable is an event that is emitted when a plugin is disabled
// It maches on the passed in plugin's ID only.
type EventDisable struct {
Plugin types.Plugin
}
func (e EventDisable) matches(observed Event) bool {
oe, ok := observed.(EventDisable)
if !ok {
return false
}
return e.Plugin.ID == oe.Plugin.ID
}
// EventEnable is an event that is emitted when a plugin is disabled
// It maches on the passed in plugin's ID only.
type EventEnable struct {
Plugin types.Plugin
}
func (e EventEnable) matches(observed Event) bool {
oe, ok := observed.(EventEnable)
if !ok {
return false
}
return e.Plugin.ID == oe.Plugin.ID
}
// SubscribeEvents provides an event channel to listen for structured events from
// the plugin manager actions, CRUD operations.
// The caller must call the returned `cancel()` function once done with the channel
// or this will leak resources.
func (pm *Manager) SubscribeEvents(buffer int, watchEvents ...Event) (eventCh <-chan interface{}, cancel func()) {
topic := func(i interface{}) bool {
observed, ok := i.(Event)
if !ok {
panic(fmt.Sprintf("unexpected type passed to event channel: %v", reflect.TypeOf(i)))
}
for _, e := range watchEvents {
if e.matches(observed) {
return true
}
}
// If no specific events are specified always assume a matched event
// If some events were specified and none matched above, then the event
// doesn't match
return watchEvents == nil
}
ch := pm.publisher.SubscribeTopicWithBuffer(topic, buffer)
cancelFunc := func() { pm.publisher.Evict(ch) }
return ch, cancelFunc
}