mb

Documentation

Overview

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

Index

• Constants
• Variables
• func NewModules(config []*common.Config, r *Register) (map[Module][]MetricSet, error)
• type BaseMetricSet
  • func (b *BaseMetricSet) GoString() string
  • func (b *BaseMetricSet) Host() string
  • func (b *BaseMetricSet) HostData() HostData
  • func (b *BaseMetricSet) Module() Module
  • func (b *BaseMetricSet) Name() string
  • func (b *BaseMetricSet) String() string
• type BaseModule
  • func (m *BaseModule) Config() ModuleConfig
  • func (m *BaseModule) GoString() string
  • func (m *BaseModule) Name() string
  • func (m *BaseModule) String() string
  • func (m *BaseModule) UnpackConfig(to interface{}) error
• type EventFetcher
• type EventsFetcher
• type HostData
  • func (h HostData) GoString() string
  • func (h HostData) String() string
• type HostParser
• type MetricSet
• type MetricSetFactory
• type Module
• type ModuleConfig
  • func DefaultModuleConfig() ModuleConfig
  • func (c ModuleConfig) GoString() string
  • func (c ModuleConfig) String() string
• type ModuleFactory
• type Register
  • func NewRegister() *Register
  • func (r *Register) AddMetricSet(module string, name string, factory MetricSetFactory, hostParser ...HostParser) error
  • func (r *Register) AddModule(name string, factory ModuleFactory) error
  • func (r Register) String() string

Examples

• MetricSetFactory
• ModuleFactory

Constants

const (
	// ModuleData 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.
	ModuleData string = "_module"
)

Variables

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")
)

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.

var Registry = NewRegister()

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

Functions

func NewModules

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

NewModules builds new Modules and their associated MetricSets based on the provided configuration data. config is a list module 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 mapping of Modules to 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 EventFetcher

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

EventFetcher is a MetricSet that returns a single event when collecting data.

type EventsFetcher

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

EventsFetcher is a MetricSet that returns a multiple events when collecting data.

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).

Example

ExampleMetricSetFactory demonstrates how to register a MetricSetFactory and unpack additional configuration data.

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
}

func (ms *MetricSet) Fetch() (common.MapStr, error) {
	// Fetch data from the host (using ms.HostData().URI) and return the data.
	return common.MapStr{
		"someParam":  "value",
		"otherParam": 42,
	}, nil
}

// ExampleMetricSetFactory demonstrates how to register a MetricSetFactory
// and unpack additional configuration data.
func main() {}

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"`
	Filters    processors.PluginConfig `config:"filters"`
	Raw        bool                    `config:"raw"`

	common.EventMetadata `config:",inline"` // Fields and tags to add to events.
}

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() {}

type Register

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

Register contains the factory functions for creating new Modules and new MetricSets.

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) String

func (r Register) String() string

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