statuscheck

Documentation

Overview

Package statuscheck defines the status report API for other CN-Infra plugins and implements the health status aggregator/exporter. Health status is collected from other plugins through the plugin status report API and aggregated and exported/exposed via ETCD or a REST API.

The API provides only two functions, one for registering the plugin for status change reporting and one for reporting status changes.

To register a plugin for providing status reports, use Register() function:

statuscheck.Register(PluginID, probe)

If probe is not nil, statuscheck will periodically probe the plugin state through the provided function. Otherwise, it is expected that the plugin itself will report state updates through ReportStateChange(), e.g.:

statuscheck.ReportStateChange(PluginID, statuscheck.OK, nil)

The default status of a plugin after registering is Init.

Index

• Variables
• type AgentStatusReader
• type Deps
• type InterfaceStatusReader
• type Option
  • func UseDeps(cb func(*Deps)) Option
• type Plugin
  • func NewPlugin(opts ...Option) *Plugin
  • func (p *Plugin) AfterInit() error
  • func (p *Plugin) Close() error
  • func (p *Plugin) GetAgentStatus() status.AgentStatus
  • func (p *Plugin) GetAllPluginStatus() map[string]*status.PluginStatus
  • func (p *Plugin) GetInterfaceStats() status.InterfaceStats
  • func (p *Plugin) Init() error
  • func (p *Plugin) Register(pluginName infra.PluginName, probe PluginStateProbe)
  • func (p *Plugin) ReportStateChange(pluginName infra.PluginName, state PluginState, lastError error)
  • func (p *Plugin) ReportStateChangeWithMeta(pluginName infra.PluginName, state PluginState, lastError error, ...)
• type PluginState
• type PluginStateProbe
• type PluginStatusWriter
• type StatusReader

Variables

var (
	// PeriodicWriteTimeout is frequency of periodic writes of state data into ETCD.
	PeriodicWriteTimeout = time.Second * 10
	// PeriodicProbingTimeout is frequency of periodic plugin state probing.
	PeriodicProbingTimeout = time.Second * 5
)

var DefaultPlugin = *NewPlugin()

DefaultPlugin is a default instance of Plugin.

Types

type AgentStatusReader

type AgentStatusReader interface {
	// GetAgentStatus returns the current global operational state of the agent.
	GetAgentStatus() status.AgentStatus
}

AgentStatusReader allows to lookup agent status by other plugins.

type Deps

type Deps struct {
	infra.PluginName                            // inject
	Log              logging.PluginLogger       // inject
	Transport        datasync.KeyProtoValWriter // inject (optional)
}

Deps lists the dependencies of statuscheck plugin.

type InterfaceStatusReader

type InterfaceStatusReader interface {
	GetInterfaceStats() status.InterfaceStats
}

InterfaceStatusReader looks up the interface state and returns updated state data

type Option

type Option func(*Plugin)

Option is a function that can be used in NewPlugin to customize Plugin.

func UseDeps

func UseDeps(cb func(*Deps)) Option

UseDeps returns Option that can inject custom dependencies.

type Plugin

type Plugin struct {
	Deps
	// contains filtered or unexported fields
}

Plugin struct holds all plugin-related data.

func NewPlugin

func NewPlugin(opts ...Option) *Plugin

NewPlugin creates a new Plugin with the provided Options.

func (*Plugin) AfterInit

func (p *Plugin) AfterInit() error

AfterInit starts go routines for periodic probing and periodic updates. Initial state data are published via the injected transport.

func (*Plugin) Close

func (p *Plugin) Close() error

Close stops go routines for periodic probing and periodic updates.

func (*Plugin) GetAgentStatus

func (p *Plugin) GetAgentStatus() status.AgentStatus

GetAgentStatus return current global operational state of the agent.

func (*Plugin) GetAllPluginStatus

func (p *Plugin) GetAllPluginStatus() map[string]*status.PluginStatus

GetAllPluginStatus returns a map containing pluginname and its status, for all plugins

func (*Plugin) GetInterfaceStats

func (p *Plugin) GetInterfaceStats() status.InterfaceStats

GetInterfaceStats returns current global operational status of interfaces

func (*Plugin) Init

func (p *Plugin) Init() error

Init prepares the initial status data.

func (*Plugin) Register

func (p *Plugin) Register(pluginName infra.PluginName, probe PluginStateProbe)

Register a plugin for status change reporting.

func (*Plugin) ReportStateChange

func (p *Plugin) ReportStateChange(pluginName infra.PluginName, state PluginState, lastError error)

ReportStateChange can be used to report a change in the status of a previously registered plugin.

func (*Plugin) ReportStateChangeWithMeta

func (p *Plugin) ReportStateChangeWithMeta(pluginName infra.PluginName, state PluginState, lastError error, meta proto.Message)

ReportStateChangeWithMeta can be used to report a change in the status of a previously registered plugin and report the specific metadata state

type PluginState

type PluginState string

PluginState is a data type used to describe the current operational state of a plugin.

const (
	// Init state means that the initialization of the plugin is in progress.
	Init PluginState = "init"
	// OK state means that the plugin is healthy.
	OK PluginState = "ok"
	// Error state means that some error has occurred in the plugin.
	Error PluginState = "error"
)

type PluginStateProbe

type PluginStateProbe func() (PluginState, error)

PluginStateProbe defines parameters of a function used for plugin state probing, referred to as "probe".

type PluginStatusWriter

type PluginStatusWriter interface {
	// Register registers a plugin for status change reporting.
	// If <probe> is not nil, Statuscheck will periodically probe the plugin
	// state through the provided function. Otherwise, it is expected that the
	// plugin itself will report state updates through ReportStateChange().
	Register(pluginName infra.PluginName, probe PluginStateProbe)

	// ReportStateChange can be used to report a change in the status
	// of a previously registered plugin. It is not a bug, however, to report
	// the same status in consecutive calls. Statuscheck is smart enough
	// to detect an actual status change and propagate only updates to remote
	// clients.
	ReportStateChange(pluginName infra.PluginName, state PluginState, lastError error)

	// ReportStateChangeWithMeta can be used to report a change in the status
	// of a previously registered plugin with added metadata value stored in
	// global agent status. Metadata type is specified in statuscheck model.
	ReportStateChangeWithMeta(pluginName infra.PluginName, state PluginState, lastError error, meta proto.Message)
}

PluginStatusWriter allows to register & write plugin status by other plugins

type StatusReader

type StatusReader interface {
	AgentStatusReader
	InterfaceStatusReader
	GetAllPluginStatus() map[string]*status.PluginStatus
}

StatusReader allows to lookup agent status and retrieve a map containing status of all plugins.