in docker/watcher.go [160:174]
func NewWatcherWithClient(log *logp.Logger, client Client, cleanupTimeout time.Duration, storeShortID bool) (Watcher, error) {
ctx, cancel := context.WithCancel(context.Background())
return &watcher{
log: log,
client: client,
ctx: ctx,
stop: cancel,
containers: make(map[string]*Container),
deleted: make(map[string]time.Time),
cleanupTimeout: cleanupTimeout,
bus: bus.New(log, "docker"),
shortID: storeShortID,
clock: &systemClock{},
}, nil
}