docs/cluster/event_monitor.go

86 lines
1.6 KiB
Go

package cluster
import (
"encoding/json"
"io"
"github.com/docker/engine-api/types"
"github.com/docker/engine-api/types/events"
"github.com/docker/swarm/swarmclient"
"golang.org/x/net/context"
)
//EventsMonitor monitors events
type EventsMonitor struct {
stopChan chan struct{}
cli swarmclient.SwarmAPIClient
handler func(msg events.Message) error
}
type decodingResult struct {
msg events.Message
err error
}
// NewEventsMonitor returns an EventsMonitor
func NewEventsMonitor(cli swarmclient.SwarmAPIClient, handler func(msg events.Message) error) *EventsMonitor {
return &EventsMonitor{
cli: cli,
handler: handler,
}
}
// Start starts the EventsMonitor
func (em *EventsMonitor) Start(ec chan error) {
em.stopChan = make(chan struct{})
responseBody, err := em.cli.Events(context.Background(), types.EventsOptions{})
if err != nil {
ec <- err
return
}
resultChan := make(chan decodingResult)
go func() {
dec := json.NewDecoder(responseBody)
for {
var result decodingResult
result.err = dec.Decode(&result.msg)
resultChan <- result
if result.err == io.EOF {
break
}
}
close(resultChan)
}()
go func() {
defer responseBody.Close()
for {
select {
case <-em.stopChan:
ec <- nil
return
case result := <-resultChan:
if result.err != nil {
ec <- result.err
return
}
if err := em.handler(result.msg); err != nil {
ec <- err
return
}
}
}
}()
}
// Stop stops the EventsMonitor
func (em *EventsMonitor) Stop() {
if em.stopChan == nil {
return
}
close(em.stopChan)
}