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Published: May 4, 2017 License: Apache-2.0 Imports: 13 Imported by: 0

Documentation

Index

Examples

Constants

This section is empty.

Variables

This section is empty.

Functions

func PublishChannels

func PublishChannels(client publisher.Client, cs ...<-chan common.MapStr)

PublishChannels publishes the events read from each channel to the given publisher client. If the publisher client blocks for any reason then events will not be read from the given channels.

This method blocks until all of the channels have been closed and are fully read. To stop the method immediately, close the channels and close the publisher client to ensure that publishing does not block. This may result is some events being discarded.

Types

type EventBuilder

type EventBuilder struct {
	ModuleName    string
	MetricSetName string
	Host          string
	StartTime     time.Time
	FetchDuration time.Duration
	Event         common.MapStr
	// contains filtered or unexported fields
}

EventBuilder is used for building MetricSet events. MetricSets generate a data in the form of a common.MapStr. This builder transforms that data into a complete event and applies any Module-level filtering.

func (EventBuilder) Build

func (b EventBuilder) Build() (common.MapStr, error)

Build builds an event from MetricSet data and applies the Module-level filters.

type Factory

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

Factory is used to register and reload modules

func NewFactory

func NewFactory(p publisher.Publisher) *Factory

NewFactory creates new Reloader instance for the given config

func (*Factory) Create

func (r *Factory) Create(c *common.Config) (cfgfile.Runner, error)

type Runner

type Runner interface {
	// Start starts the Module. If Start is called more than once, only the
	// first will start the Module.
	Start()

	// Stop stops the Module and waits for module's MetricSets to exit. The
	// publisher.Client will be closed by Stop. If Stop is called more than
	// once, only the first stop the Module and wait for it to exit.
	Stop()

	// Added to be consistent with cfgfile.Runner
	ID() uint64
}

Runner is a facade for a Wrapper that provides a simple interface for starting and stopping a Module.

Example

ExampleRunner demonstrates how to use Runner to start and stop a module.

// A *beat.Beat is injected into a Beater when it runs and contains the
// Publisher used to publish events. This Beat pointer is created here only
// for demonstration purposes.
var b *beat.Beat

config, err := common.NewConfigFrom(map[string]interface{}{
	"module":     moduleName,
	"metricsets": []string{metricSetName},
})
if err != nil {
	return
}

// Create a new Wrapper based on the configuration.
m, err := module.NewWrapper(config, mb.Registry)
if err != nil {
	return
}

// Create the Runner facade.
runner := module.NewRunner(b.Publisher.Connect, m)

// Start the module and have it publish to a new publisher.Client.
runner.Start()

// Stop the module. This blocks until all MetricSets in the Module have
// stopped and the publisher.Client is closed.
runner.Stop()
Output:

func NewRunner

func NewRunner(pubClientFactory func() publisher.Client, mod *Wrapper) Runner

NewRunner returns a Runner facade. The events generated by the Module will be published to a new publisher.Client generated from the pubClientFactory.

type Wrapper

type Wrapper struct {
	mb.Module
	// contains filtered or unexported fields
}

Wrapper contains the Module and the private data associated with running the Module and its MetricSets.

Use NewWrapper or NewWrappers to construct new Wrappers.

Example

ExampleWrapper demonstrates how to create a single Wrapper from configuration, start the module, and consume events generated by the module.

// Build a configuration object.
config, err := common.NewConfigFrom(map[string]interface{}{
	"module":     moduleName,
	"metricsets": []string{metricSetName},
})
if err != nil {
	fmt.Println("Error:", err)
	return
}

// Create a new Wrapper based on the configuration.
m, err := module.NewWrapper(config, mb.Registry)
if err != nil {
	fmt.Println("Error:", err)
	return
}

// Run the module until done is closed.
done := make(chan struct{})
output := m.Start(done)

// Process events from the output channel until it is closed.
var wg sync.WaitGroup
wg.Add(1)
go func() {
	defer wg.Done()
	for event := range output {
		// Make rtt a constant so that the output is constant.
		event["metricset"].(common.MapStr)["rtt"] = 111
		fmt.Println(event.StringToPrint())
	}
}()

// Simulate running for a while.
time.Sleep(50 * time.Millisecond)

// When finished with the module, close the done channel. When the Module
// stops it will automatically close its output channel so that the output
// for loop stops.
close(done)
wg.Wait()
Output:

{
  "@timestamp": "2016-05-10T23:27:58.485Z",
  "_event_metadata": {
    "Fields": null,
    "FieldsUnderRoot": false,
    "Tags": null
  },
  "fake": {
    "status": {
      "metric": 1
    }
  },
  "metricset": {
    "module": "fake",
    "name": "status",
    "rtt": 111
  },
  "type": "metricsets"
}

func NewWrapper

func NewWrapper(moduleConfig *common.Config, r *mb.Register) (*Wrapper, error)

NewWrapper create a new Module and its associated MetricSets based on the given configuration. It constructs the supporting filters and stores them in the Wrapper.

func NewWrappers

func NewWrappers(modulesConfig []*common.Config, r *mb.Register) ([]*Wrapper, error)

NewWrappers creates new Modules and their associated MetricSets based on the given configuration. It constructs the supporting filters and stores them all in a Wrapper.

func (*Wrapper) Hash

func (mw *Wrapper) Hash() uint64

Hash returns the hash value of the module wrapper This allows to check if two modules are the same / have the same config

func (*Wrapper) Start

func (mw *Wrapper) Start(done <-chan struct{}) <-chan common.MapStr

Start starts the Module's MetricSet workers which are responsible for fetching metrics. The workers will continue to periodically fetch until the done channel is closed. When the done channel is closed all MetricSet workers will stop and the returned output channel will be closed.

The returned channel is buffered with a length one one. It must drained to prevent blocking the operation of the MetricSets.

Start should be called only once in the life of a Wrapper.

func (*Wrapper) String

func (mw *Wrapper) String() string

String returns a string representation of Wrapper.

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