beat

type Beat struct {
	Info      Info     // beat metadata.
	Publisher Pipeline // Publisher pipeline

	SetupMLCallback SetupMLCallback // setup callback for ML job configs
	InSetupCmd      bool            // this is set to true when the `setup` command is called

	// XXX: remove Config from public interface.
	//      It's currently used by filebeat modules to setup the Ingest Node
	//      pipeline and ML jobs.
	Config *BeatConfig // Common Beat configuration data.

	BeatConfig *common.Config // The beat's own configuration section
}

type BeatConfig struct {
	// output/publishing related configurations
	Output common.ConfigNamespace `config:"output"`
}

type Beater interface {
	// The main event loop. This method should block until signalled to stop by an
	// invocation of the Stop() method.
	Run(b *Beat) error

	// Stop is invoked to signal that the Run method should finish its execution.
	// It will be invoked at most once.
	Stop()
}

type Client interface {
	Publish(Event)
	PublishAll([]Event)
	Close() error
}

type ClientConfig struct {
	PublishMode PublishMode

	// EventMetadata configures additional fields/tags to be added to published events.
	EventMetadata common.EventMetadata

	// Meta provides additional meta data to be added to the Meta field in the beat.Event
	// structure.
	Meta common.MapStr

	// Fields provides additional 'global' fields to be added to every event
	Fields common.MapStr

	// DynamicFields provides additional fields to be added to every event, supporting live updates
	DynamicFields *common.MapStrPointer

	// Processors passes additional processor to the client, to be executed before
	// the pipeline processors.
	Processor ProcessorList

	// WaitClose sets the maximum duration to wait on ACK, if client still has events
	// active non-acknowledged events in the publisher pipeline.
	// WaitClose is only effective if one of ACKCount, ACKEvents and ACKLastEvents
	// is configured
	WaitClose time.Duration

	// Events configures callbacks for common client callbacks
	Events ClientEventer

	// ACKCount reports the number of published events recently acknowledged
	// by the pipeline.
	ACKCount func(int)

	// ACKEvents reports the events private data of recently acknowledged events.
	// Note: The slice passed must be copied if the events are to be processed
	//       after the handler returns.
	ACKEvents func([]interface{})

	// ACKLastEvent reports the last ACKed event out of a batch of ACKed events only.
	// Only the events 'Private' field will be reported.
	ACKLastEvent func(interface{})
}

type ClientEventer interface {
	Closing() // Closing indicates the client is being shutdown next
	Closed()  // Closed indicates the client being fully shutdown

	Published()             // event has been successfully forwarded to the publisher pipeline
	FilteredOut(Event)      // event has been filtered out/dropped by processors
	DroppedOnPublish(Event) // event has been dropped, while waiting for the queue
}

type Creator func(*Beat, *common.Config) (Beater, error)

type Event struct {
	Timestamp time.Time
	Meta      common.MapStr
	Fields    common.MapStr
	Private   interface{} // for beats private use
}

type Info struct {
	Beat        string    // The actual beat's name
	IndexPrefix string    // The beat's index prefix in Elasticsearch.
	Version     string    // The beat version. Defaults to the libbeat version when an implementation does not set a version
	Name        string    // configured beat name
	Hostname    string    // hostname
	UUID        uuid.UUID // ID assigned to beat instance
}

type Pipeline interface {
	Connect() (Client, error)
	ConnectWith(ClientConfig) (Client, error)
	SetACKHandler(PipelineACKHandler) error
}

type PipelineACKHandler struct {
	// ACKCount reports the number of published events recently acknowledged
	// by the pipeline.
	ACKCount func(int)

	// ACKEvents reports the events recently acknowledged by the pipeline.
	// Only the events 'Private' field will be reported.
	ACKEvents func([]interface{})

	// ACKLastEvent reports the last ACKed event per pipeline client.
	// Only the events 'Private' field will be reported.
	ACKLastEvents func([]interface{})
}

type Processor interface {
	String() string // print full processor description
	Run(in *Event) (event *Event, err error)
}

type ProcessorList interface {
	All() []Processor
}

type PublishMode uint8

type SetupMLCallback func(*Beat) error