schedulers

README

Schedulers

Schedulers are the components responsible for managing log sources (pkg/log/sources.LogSource) and services [1]. These sources and services are then recognized by logs-agent launchers, which create tailers and attach them to the logs-agent pipeline.

In short, schedulers control what is and is not logged, and how it is logged.

The logs-agent maintains a set of current schedulers, starting them at startup and stopping them when the logs-agent stops.

[1] In planned development, schedulers will only manage sources, not services.

Documentation

Index

• type MockAddRemove
• type MockSourceManager
  • func (sm *MockSourceManager) AddService(service *service.Service)
  • func (sm *MockSourceManager) AddSource(source *sources.LogSource)
  • func (sm *MockSourceManager) GetSources() []*sources.LogSource
  • func (sm *MockSourceManager) RemoveService(service *service.Service)
  • func (sm *MockSourceManager) RemoveSource(source *sources.LogSource)
• type Scheduler
• type Schedulers
  • func NewSchedulers(sources *sources.LogSources, services *service.Services) *Schedulers
  • func (ss *Schedulers) AddScheduler(scheduler Scheduler)
  • func (ss *Schedulers) GetSources() []*sources.LogSource
  • func (ss *Schedulers) Start()
  • func (ss *Schedulers) Stop()
• type SourceManager

Types

type MockAddRemove

type MockAddRemove struct {
	// Added is true if this source was added; otherwise it was removed
	Add bool

	// Source is the source that was added or removed, or nil.
	Source *sources.LogSource

	// Service is the service that was added or removed, or nil.
	Service *service.Service
}

MockAddRemove is an event observed by MockSourceManager

type MockSourceManager

type MockSourceManager struct {
	// Events are the events that occurred in the spy
	Events []MockAddRemove

	// Sources are the sources returned by GetSources
	Sources []*sources.LogSource
}

MockSourceManager is a "spy" that records the AddSource and RemoveSource calls that it receives.

This is a useful tool in testing schedulers. Its zero value is a valid beginning state.

func (*MockSourceManager) AddService

func (sm *MockSourceManager) AddService(service *service.Service)

AddService implements SourceManager#AddService.

func (*MockSourceManager) AddSource

func (sm *MockSourceManager) AddSource(source *sources.LogSource)

AddSource implements SourceManager#AddSource.

func (*MockSourceManager) GetSources

func (sm *MockSourceManager) GetSources() []*sources.LogSource

GetSources implements SourceManager#GetSources.

func (*MockSourceManager) RemoveService

func (sm *MockSourceManager) RemoveService(service *service.Service)

RemoveService implements SourceManager#RemoveService.

func (*MockSourceManager) RemoveSource

func (sm *MockSourceManager) RemoveSource(source *sources.LogSource)

RemoveSource implements SourceManager#RemoveSource.

type Scheduler

type Scheduler interface {
	// Start the scheduler, managing sources and services via the given manager.
	Start(sourceMgr SourceManager)

	// Stop the scheduler, and wait until shutdown is complete.  It is not
	// necessary to remove sources or services here, but any background
	// goroutines or other resources should be freed.
	Stop()
}

Scheduler implementations manage logs-agent sources.

Schedulers are started when the logs-agent starts, and stopped when it stops.

type Schedulers

type Schedulers struct {
	// contains filtered or unexported fields
}

Schedulers manages a collection of schedulers.

func NewSchedulers

func NewSchedulers(sources *sources.LogSources, services *service.Services) *Schedulers

NewSchedulers creates a new, empty Schedulers instance

func (*Schedulers) AddScheduler

func (ss *Schedulers) AddScheduler(scheduler Scheduler)

AddScheduler adds a scheduler to the collection. If called after Start(), then the scheduler will be started immediately.

func (*Schedulers) GetSources

func (ss *Schedulers) GetSources() []*sources.LogSource

GetSources returns all the log source from the source manager.

func (*Schedulers) Start

func (ss *Schedulers) Start()

Start starts all schedulers in the collection.

func (*Schedulers) Stop

func (ss *Schedulers) Stop()

Stop all schedulers and wait until they are complete.

type SourceManager

type SourceManager interface {
	// AddSource adds a new source to the logs agent.  The new source is
	// distributed to all active launchers, which may create appropriate
	// tailers and begin forwarding messages.
	AddSource(source *sources.LogSource)

	// RemoveSource removes an existing source from the logs agent.  The
	// source is recognized by pointer equality.
	RemoveSource(source *sources.LogSource)

	// GetSources returns all the sources currently held.  The result is copied and
	// will not be modified after it is returned, and represents a "snapshot" of the
	// state when the function was called.
	GetSources() []*sources.LogSource

	// AddService adds a new service to the logs agent.
	AddService(service *service.Service)

	// RemoveService removes a service added with AddService.  The source
	// is recognized by pointer equality.
	RemoveService(service *service.Service)
}

SourceManager is the interface by which schedulers add and remove sources from the agent.

(services are also included here, temporarily)