service

Documentation

Overview

Package service defines the interface that fleetspeak client side services must implement, along with some related types.

Index

• type AckMessage
• type Context
• type Factory
• type LocalInfo
• type Service
  • func NOOPFactory(conf *fspb.ClientServiceConfig) (Service, error)

Types

type AckMessage

type AckMessage struct {
	M   *fspb.Message
	Ack func()
}

AckMessage is a message that can be acknowledged. If no acknowledgement is required, Ack may be nil.

type Context

type Context interface {
	// Send provides a message to the Fleetspeak system for delivery to the server or to other
	// Fleetspeak services running on the local client.
	Send(context.Context, AckMessage) error

	// GetLocalInfo returns information about the local client.
	GetLocalInfo() *LocalInfo

	// GetFileIfModified attempts to retrieve a file from the server, if it been modified since
	// modSince. Return values follow the semantics of Communicator.GetFileIfModified.
	GetFileIfModified(ctx context.Context, name string, modSince time.Time) (data io.ReadCloser, mod time.Time, err error)

	// StatsCollector returns the stats.Collector used by the Fleetspeak client.
	Stats() stats.Collector
}

A Context encapsulates the functionality that the Fleetspeak client installation provides to a configured service.

type Factory

type Factory func(conf *fspb.ClientServiceConfig) (Service, error)

A Factory creates a Service according to a provided configuration.

type LocalInfo

type LocalInfo struct {
	ClientID common.ClientID // The ClientID of the local client.
	Labels   []*fspb.Label   // The client labels (ServiceName="client") set on the local client.
	Services []string        // The Fleetspeak services currently configured on the local client.
}

LocalInfo stores summary information about the local client.

type Service

type Service interface {
	// Start performs any necessary setup for the Service.
	//
	// If it returns nil Fleetspeak will assume that the service is ready to
	// process messages. Otherwise Fleetspeak will consider the service
	// unavailable.
	Start(Context) error

	// ProcessMessage processes one message.
	//
	// If it returns nil, Fleetspeak will acknowledge the message and it
	// will be marked as successfully processed. If it returns an error, the
	// message will be marked as failed.
	//
	// Note however that in either case, the delivery of the acknowledgement
	// is not guaranteed and there is a chance that the message will be sent
	// again.
	ProcessMessage(context.Context, *fspb.Message) error

	// Stop shuts down the service in an orderly manner.
	Stop() error
}

A Service represents a configured client component which can accept and send messages via Fleetspeak.

func NOOPFactory

func NOOPFactory(conf *fspb.ClientServiceConfig) (Service, error)

NOOPFactory is a Factory which produces a service that does nothing. It accepts any message without processing it, and produces no messages for the server.