mb

package
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 Go to latest Published: Dec 2, 2017 License: Apache-2.0 Imports: 9 Imported by: 0

Documentation

Overview

Package mb (short for Metricbeat) contains the public interfaces that are used to implement Modules and their associated MetricSets.

Index

Examples

Constants

View Source 
const (
	// ModuleDataKey is the key used in events created by MetricSets to add data
	// to an event that is common to the module. The data must be a
	// common.MapStr and when the final event is built the object will be stored
	// in the event under a key that is the module name.
	ModuleDataKey string = "_module"

	// NamespaceKey is used to define a different namespace for the metricset
	// This is useful for dynamic metricsets or metricsets which do not
	// put the name under the same name as the package. This is for example
	// the case in elasticsearch `node_stats` which puts the data under `node.stats`.
	NamespaceKey string = "_namespace"
)

Variables

View Source 
var (
	// ErrEmptyConfig indicates that modules configuration list is nil or empty.
	ErrEmptyConfig = errors.New("one or more modules must be configured")

	// ErrAllModulesDisabled indicates that all modules are disabled. At least
	// one module must be enabled.
	ErrAllModulesDisabled = errors.New("all modules are disabled")

	// ErrModuleDisabled indicates a disabled module has been tried to instantiate.
	ErrModuleDisabled = errors.New("disabled module")
)
View Source 
var DefaultModuleFactory = func(base BaseModule) (Module, error) {
	return &base, nil
}

DefaultModuleFactory returns the given BaseModule and never returns an error. If a MetricSets are registered without an associated ModuleFactory, then the DefaultModuleFactory will be used to instantiate a Module.

View Source 
var Registry = NewRegister()

Registry is the singleton Register instance where all ModuleFactory's and MetricSetFactory's should be registered.

Functions

func NewModule 

func NewModule(config *common.Config, r *Register) (Module, []MetricSet, error)

NewModule builds a new Module and its associated MetricSets based on the provided configuration data. config contains config data (the data will be unpacked into ModuleConfig structs). r is the Register where the ModuleFactory's and MetricSetFactory's will be obtained from. This method returns a Module and its configured MetricSets or an error.

Types

type BaseMetricSet 

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

BaseMetricSet implements the MetricSet interface.

The BaseMetricSet type can be embedded into another struct to satisfy the MetricSet interface requirements, leaving only the Fetch() method to be implemented to have a complete MetricSet implementation.

func (*BaseMetricSet) GoString 

func (b *BaseMetricSet) GoString() string

func (*BaseMetricSet) Host 

func (b *BaseMetricSet) Host() string

Host returns the hostname or other module specific value that identifies a specific host or service instance from which to collect metrics.

func (*BaseMetricSet) HostData 

func (b *BaseMetricSet) HostData() HostData

HostData returns the parsed host data.

func (*BaseMetricSet) Module 

func (b *BaseMetricSet) Module() Module

Module returns the parent Module for the MetricSet.

func (*BaseMetricSet) Name 

func (b *BaseMetricSet) Name() string

Name returns the name of the MetricSet. It should not include the name of the module.

func (*BaseMetricSet) String 

func (b *BaseMetricSet) String() string

type BaseModule 

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

BaseModule implements the Module interface.

When a Module needs to store additional data or provide methods to its MetricSets, it can embed this type into another struct to satisfy the Module interface requirements.

func (*BaseModule) Config 

func (m *BaseModule) Config() ModuleConfig

Config returns the ModuleConfig used to create the Module.

func (*BaseModule) GoString 

func (m *BaseModule) GoString() string

func (*BaseModule) Name 

func (m *BaseModule) Name() string

Name returns the name of the Module.

func (*BaseModule) String 

func (m *BaseModule) String() string

func (*BaseModule) UnpackConfig 

func (m *BaseModule) UnpackConfig(to interface{}) error

UnpackConfig unpacks the raw module config to the given object.

type Closer 

type Closer interface {
	Close() error
}

Closer is an optional interface that a MetricSet can implement in order to cleanup any resources it has open at shutdown.

type EventFetcher 

type EventFetcher interface {
	MetricSet
	Fetch() (common.MapStr, error)
}

EventFetcher is a MetricSet that returns a single event when collecting data. Use ReportingMetricSet for new MetricSet implementations.

type EventsFetcher 

type EventsFetcher interface {
	MetricSet
	Fetch() ([]common.MapStr, error)
}

EventsFetcher is a MetricSet that returns a multiple events when collecting data. Use ReportingMetricSet for new MetricSet implementations.

type HostData 

type HostData struct {
	URI          string // The full URI that should be used in connections.
	SanitizedURI string // A sanitized version of the URI without credentials.

	Host     string // The host and possibly port.
	User     string // Username
	Password string // Password
}

HostData contains values parsed from the 'host' configuration. Other configuration data like protocols, usernames, and passwords may also be used to construct this HostData data.

func (HostData) GoString 

func (h HostData) GoString() string

func (HostData) String 

func (h HostData) String() string

type HostParser 

type HostParser func(module Module, host string) (HostData, error)

HostParser is a function that parses a host value from the configuration and returns a HostData object. The module is provided in case additional configuration values are required to parse and build the HostData object. An error should be returned if the host or configuration is invalid.

type MetricSet 

type MetricSet interface {
	Name() string   // Name returns the name of the MetricSet.
	Module() Module // Module returns the parent Module for the MetricSet.
	Host() string   // Host returns a hostname or other module specific value
	// that identifies a specific host or service instance from which to collect
	// metrics.
	HostData() HostData // HostData returns the parsed host data.
}

MetricSet is the common interface for all MetricSet implementations. In addition to this interface, all MetricSets must implement either EventFetcher or EventsFetcher (but not both).

type MetricSetFactory 

type MetricSetFactory func(base BaseMetricSet) (MetricSet, error)

MetricSetFactory accepts a BaseMetricSet and returns a MetricSet. If there was an error creating the MetricSet then an error will be returned. The returned MetricSet must also implement either EventFetcher or EventsFetcher (but not both).

type Module 

type Module interface {
	Name() string                      // Name returns the name of the Module.
	Config() ModuleConfig              // Config returns the ModuleConfig used to create the Module.
	UnpackConfig(to interface{}) error // UnpackConfig unpacks the raw module config to the given object.
}

Module is the common interface for all Module implementations.

type ModuleConfig 

type ModuleConfig struct {
	Hosts      []string      `config:"hosts"`
	Period     time.Duration `config:"period"     validate:"positive"`
	Timeout    time.Duration `config:"timeout"    validate:"positive"`
	Module     string        `config:"module"     validate:"required"`
	MetricSets []string      `config:"metricsets" validate:"required"`
	Enabled    bool          `config:"enabled"`
	Raw        bool          `config:"raw"`
}

ModuleConfig is the base configuration data for all Modules.

The Raw config option is used to enable raw fields in a metricset. This means the metricset fetches not only the predefined fields but add alls raw data under the raw namespace to the event.

func DefaultModuleConfig 

func DefaultModuleConfig() ModuleConfig

DefaultModuleConfig returns a ModuleConfig with the default values populated.

func (ModuleConfig) GoString 

func (c ModuleConfig) GoString() string

func (ModuleConfig) String 

func (c ModuleConfig) String() string

type ModuleFactory 

type ModuleFactory func(base BaseModule) (Module, error)

ModuleFactory accepts a BaseModule and returns a Module. If there was an error creating the Module then an error will be returned.

Example

ExampleModuleFactory demonstrates how to register a custom ModuleFactory and unpack additional configuration data. 

package main

import (
	"github.com/elastic/beats/metricbeat/mb"
)

func init() {
	// Register the ModuleFactory function for the "example" module.
	if err := mb.Registry.AddModule("example", NewModule); err != nil {
		panic(err)
	}
}

type Module struct {
	mb.BaseModule
	Protocol string
}

func NewModule(base mb.BaseModule) (mb.Module, error) {
	// Unpack additional configuration options.
	config := struct {
		Protocol string `config:"protocol"`
	}{
		Protocol: "udp",
	}
	if err := base.UnpackConfig(&config); err != nil {
		return nil, err
	}

	return &Module{BaseModule: base, Protocol: config.Protocol}, nil
}

// ExampleModuleFactory demonstrates how to register a custom ModuleFactory
// and unpack additional configuration data.
func main() {}

Output:

type PushMetricSet 

type PushMetricSet interface {
	MetricSet
	Run(r PushReporter)
}

PushMetricSet is a MetricSet that pushes events (rather than pulling them periodically via a Fetch callback). Run is invoked to start the event subscription and it should block until the MetricSet is ready to stop or the PushReporter's done channel is closed.

type PushReporter 

type PushReporter interface {
	Reporter

	// Done returns a channel that's closed when work done on behalf of this
	// reporter should be canceled.
	Done() <-chan struct{}
}

PushReporter is used by a MetricSet to report events, errors, or errors with metadata. It provides a done channel used to signal that reporter should stop.

type Register 

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

Register contains the factory functions for creating new Modules and new MetricSets. Registers are thread safe for concurrent usage.

func NewRegister 

func NewRegister() *Register

NewRegister creates and returns a new Register.

func (*Register) AddMetricSet 

func (r *Register) AddMetricSet(module string, name string, factory MetricSetFactory, hostParser ...HostParser) error

AddMetricSet registers a new MetricSetFactory. Optionally it accepts a single HostParser function for parsing the 'host' configuration data. An error is returned if any parameter is empty or nil or if a factory has already been registered under the name.

func (*Register) AddModule 

func (r *Register) AddModule(name string, factory ModuleFactory) error

AddModule registers a new ModuleFactory. An error is returned if the name is empty, factory is nil, or if a factory has already been registered under the name.

func (*Register) MetricSets 

func (r *Register) MetricSets(module string) []string

MetricSets returns the list of metricsets registered for a given module

func (*Register) Modules 

func (r *Register) Modules() []string

Modules returns the list of module names that are registered

func (*Register) String 

func (r *Register) String() string

String return a string representation of the registered ModuleFactory's and MetricSetFactory's.

type Reporter 

type Reporter interface {
	Event(event common.MapStr) bool               // Event reports a single successful event.
	ErrorWith(err error, meta common.MapStr) bool // ErrorWith reports a single error event with the additional metadata.
	Error(err error) bool                         // Error reports a single error event.
}

Reporter is used by a MetricSet to report events, errors, or errors with metadata. The methods return false if and only if publishing failed because the MetricSet is being closed.

type ReportingMetricSet 

type ReportingMetricSet interface {
	MetricSet
	Fetch(r Reporter)
}

ReportingMetricSet is a MetricSet that reports events or errors through the Reporter interface. Fetch is called periodically to collect events.

Example

ExampleReportingMetricSet demonstrates how to register a MetricSetFactory and implement a ReportingMetricSet. 

package main

import (
	"fmt"

	"github.com/elastic/beats/libbeat/common"
	"github.com/elastic/beats/metricbeat/mb"
	"github.com/elastic/beats/metricbeat/mb/parse"
)

var hostParser = parse.URLHostParserBuilder{
	DefaultScheme: "http",
}.Build()

func init() {
	// Register the MetricSetFactory function for the "status" MetricSet.
	if err := mb.Registry.AddMetricSet("someapp", "status", NewMetricSet, hostParser); err != nil {
		panic(err)
	}
}

type MetricSet struct {
	mb.BaseMetricSet
}

func NewMetricSet(base mb.BaseMetricSet) (mb.MetricSet, error) {
	fmt.Println("someapp-status url=", base.HostData().SanitizedURI)
	return &MetricSet{BaseMetricSet: base}, nil
}

// Fetch will be called periodically by the framework.
func (ms *MetricSet) Fetch(report mb.Reporter) {
	// Fetch data from the host at ms.HostData().URI and return the data.
	data, err := common.MapStr{
		"some_metric":          18.0,
		"answer_to_everything": 42,
	}, error(nil)
	if err != nil {
		// Report an error if it occurs.
		report.Error(err)
		return
	}

	// Otherwise report the collected data.
	report.Event(data)
}

// ExampleReportingMetricSet demonstrates how to register a MetricSetFactory
// and implement a ReportingMetricSet.
func main() {}

Output:

Source Files

View all Source files

Directories

Path Synopsis
Package testing provides utility functions for testing Module and MetricSet implementations.
 Package testing provides utility functions for testing Module and MetricSet implementations.

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