agent

Documentation

Overview

Package agent is the running Sensu agent. Agents connect to a Sensu backend, register their presence, subscribe to check channels, download relevant check packages, execute checks, and send results to the Sensu backend via the Event channel.

Package agent is the running Sensu agent. Agents connect to a Sensu backend, register their presence, subscribe to check channels, download relevant check packages, execute checks, and send results to the Sensu backend via the Event channel.

Index

• Constants
• func GetDefaultAgentName() string
• func NewClientFromViper(v *viper.Viper, a *Agent) (gostatsd.Backend, error)
• func NewServer() *statsd.Server
• func NewStatsdServer(a *Agent) *statsd.Server
• func TestEnvVars(t *testing.T)
• func TokenSubstitution(data, input interface{}) ([]byte, error)
• type APIConfig
• type Agent
  • func NewAgent(config *Config) (*Agent, error)
  • func (a *Agent) Connected() bool
  • func (a *Agent) ExecuteHooks(request *types.CheckRequest, status int) []*types.Hook
  • func (a *Agent) Run(ctx context.Context) error
  • func (a *Agent) StartAPI(ctx context.Context)
  • func (a *Agent) StartSocketListeners(ctx context.Context)
  • func (a *Agent) StartStatsd(ctx context.Context)
• type BackendSelector
• type Client
  • func NewClient(a *Agent) (*Client, error)
  • func (Client) Name() string
  • func (Client) SendEvent(ctx context.Context, e *gostatsd.Event) (retErr error)
  • func (c Client) SendMetricsAsync(ctx context.Context, metrics *gostatsd.MetricMap, cb gostatsd.SendCallback)
• type Config
  • func FixtureConfig() (*Config, func())
  • func NewConfig() *Config
• type RandomBackendSelector
  • func (b *RandomBackendSelector) Select() string
• type SocketConfig
• type StatsdServerConfig
• type Transformer

Constants

const (
	// MaxMessageBufferSize specifies the maximum number of messages of a given
	// type that an agent will queue before rejecting messages.
	MaxMessageBufferSize = 10

	// TCPSocketReadDeadline specifies the maximum time the TCP socket will wait
	// to receive data.
	TCPSocketReadDeadline = 500 * time.Millisecond

	// DefaultAPIHost specifies the default API Host
	DefaultAPIHost = "127.0.0.1"

	// DefaultAPIPort specifies the default API Port
	DefaultAPIPort = 3031

	// DefaultBackendURL specifies the default backend URL
	DefaultBackendURL = "ws://127.0.0.1:8081"

	// DefaultEventsAPIRateLimit defines the rate limit, in events per second,
	// for outgoing events.
	DefaultEventsAPIRateLimit rate.Limit = 10.0

	// DefaultEventsAPIBurstLimit defines the burst ceiling for a rate limited
	// events API. If DefaultEventsAPIRateLimit is 0, then the setting has no
	// effect.
	DefaultEventsAPIBurstLimit int = 10

	// DefaultKeepaliveInterval specifies the default keepalive interval
	DefaultKeepaliveInterval = 20

	// DefaultNamespace specifies the default namespace
	DefaultNamespace = "default"

	// DefaultPassword specifies the default password
	DefaultPassword = "P@ssw0rd!"

	// DefaultSocketHost specifies the default socket host
	DefaultSocketHost = "127.0.0.1"

	// DefaultSocketPort specifies the default socket port
	DefaultSocketPort = 3030

	// DefaultStatsdDisable specifies if the statsd listener is disabled
	DefaultStatsdDisable = false

	// DefaultStatsdFlushInterval specifies the default flush interval for statsd
	DefaultStatsdFlushInterval = 10

	// DefaultStatsdMetricsHost specifies the default metrics host for statsd server
	DefaultStatsdMetricsHost = "127.0.0.1"

	// DefaultStatsdMetricsPort specifies the default metrics port for statsd server
	DefaultStatsdMetricsPort = 8125

	// DefaultSystemInfoRefreshInterval specifies the default refresh interval
	// (in seconds) for the agent's cached system information.
	DefaultSystemInfoRefreshInterval = 20

	// DefaultUser specifies the default user
	DefaultUser = "agent"
)

const BackendName = "sensu-statsd"

BackendName is the name of this statsd backend.

Functions

func GetDefaultAgentName

func GetDefaultAgentName() string

GetDefaultAgentName returns the default agent name

func NewClientFromViper

func NewClientFromViper(v *viper.Viper, a *Agent) (gostatsd.Backend, error)

NewClientFromViper constructs a sensu-statsd backend.

func NewServer

func NewServer() *statsd.Server

NewServer will create a new statsd Server with the default configuration.

func NewStatsdServer

func NewStatsdServer(a *Agent) *statsd.Server

NewStatsdServer provides a new statsd server for the sensu-agent.

func TestEnvVars

func TestEnvVars(t *testing.T)

func TokenSubstitution

func TokenSubstitution(data, input interface{}) ([]byte, error)

TokenSubstitution evaluates the input template, that possibly contains tokens, with the provided data object and returns a slice of bytes representing the result along with any error encountered

Types

type APIConfig

type APIConfig struct {
	Host string
	Port int
}

APIConfig contains the API configuration

type Agent

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

An Agent receives and acts on messages from a Sensu Backend.

func NewAgent

func NewAgent(config *Config) (*Agent, error)

NewAgent creates a new Agent. It returns non-nil error if there is any error when creating the config.CacheDir.

func (*Agent) Connected

func (a *Agent) Connected() bool

Connected returns true if the agent is connected to a backend.

func (*Agent) ExecuteHooks

func (a *Agent) ExecuteHooks(request *types.CheckRequest, status int) []*types.Hook

ExecuteHooks executes all hooks contained in a check request based on the check status code of the check request

func (*Agent) Run

func (a *Agent) Run(ctx context.Context) error

Run starts the Agent.

1. Start the asset manager. 2. Start a statsd server on the agent and logs the received metrics. 3. Connect to the backend, return an error if unsuccessful. 4. Start the socket listeners, return an error if unsuccessful. 5. Start the send/receive pumps. 6. Issue a keepalive immediately. 7. Start refreshing system info periodically. 8. Start sending periodic keepalives. 9. Start the API server, shutdown the agent if doing so fails.

func (*Agent) StartAPI

func (a *Agent) StartAPI(ctx context.Context)

StartAPI starts the Agent HTTP API. After attempting to start the API, if the HTTP server encounters a fatal error, it will shutdown the rest of the agent.

func (*Agent) StartSocketListeners

func (a *Agent) StartSocketListeners(ctx context.Context)

StartSocketListeners starts the agent's TCP and UDP socket listeners. Agent TCP/UDP sockets are deprecated in favor of the agent rest api.

func (*Agent) StartStatsd

func (a *Agent) StartStatsd(ctx context.Context)

StartStatsd starts up a StatsD listener on the agent, logs an error for any failures.

type BackendSelector

type BackendSelector interface {
	// Select returns an appropriate backend given the selection strategy for
	// the selector.
	Select() string
}

A BackendSelector is repsonsible for selecting an appropriate backend from a provided list of backends.

type Client

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

Client is an object that is used to send messages to sensu-statsd.

func NewClient

func NewClient(a *Agent) (*Client, error)

NewClient constructs a sensu-statsd backend.

func (Client) Name

func (Client) Name() string

Name returns the name of the backend.

func (Client) SendEvent

func (Client) SendEvent(ctx context.Context, e *gostatsd.Event) (retErr error)

SendEvent sends event to the statsd backend which resides on the sensu-agent, not to be confused with the sensu-backend.

func (Client) SendMetricsAsync

func (c Client) SendMetricsAsync(ctx context.Context, metrics *gostatsd.MetricMap, cb gostatsd.SendCallback)

SendMetricsAsync flushes the metrics to the statsd backend which resides on the sensu-agent, preparing payload synchronously but doing the send asynchronously. Must not read/write MetricMap asynchronously.

type Config

type Config struct {
	// AgentName is the entity name for the running agent. Default is hostname.
	AgentName string

	// API contains the Sensu client HTTP API configuration
	API *APIConfig

	// BackendURLs is a list of URLs for the Sensu Backend. Default:
	// ws://127.0.0.1:8081
	BackendURLs []string

	// CacheDir path where cached data is stored
	CacheDir string

	// Deregister indicates whether the entity is ephemeral
	Deregister bool

	// DeregistrationHandler specifies a single deregistration handler
	DeregistrationHandler string

	// DisableAPI disables the events API
	DisableAPI bool

	// DisableSockets disables the event sockets
	DisableSockets bool

	// EventsAPIRateLimit is the maximum number of events per second that will
	// be transmitted to the backend from the events API
	EventsAPIRateLimit rate.Limit

	// EventsAPIBurstLimit is the maximum amount of burst allowed in a rate
	// interval.
	EventsAPIBurstLimit int

	// KeepaliveInterval is the interval between keepalive events.
	KeepaliveInterval uint32

	// KeepaliveTimeout is the time after which a sensu-agent is considered dead
	// by the backend. See DefaultKeepaliveTimeout in types package for default
	// value.
	KeepaliveTimeout uint32

	// Labels are key-value pairs that users can provide to agent entities
	Labels map[string]string

	// Annotations are key-value pairs that users can provide to agent entities
	Annotations map[string]string

	// Namespace sets the Agent's RBAC namespace identifier
	Namespace string

	// Password sets Agent's password
	Password string

	// Redact contains the fields to redact when marshalling the agent's entity
	Redact []string

	// Socket contains the Sensu client socket configuration
	Socket *SocketConfig

	// StatsdServer contains the statsd server configuration
	StatsdServer *StatsdServerConfig

	// Subscriptions is an array of subscription names. Default: empty array.
	Subscriptions []string

	// TLS sets the TLSConfig for agent TLS options
	TLS *types.TLSOptions

	// User sets the Agent's username
	User string
}

A Config specifies Agent configuration.

func FixtureConfig

func FixtureConfig() (*Config, func())

FixtureConfig provides a new Config object initialized with defaults for use in tests, as well as a cleanup function to call at the end of the test.

func NewConfig

func NewConfig() *Config

NewConfig provides a new empty Config object

type RandomBackendSelector

type RandomBackendSelector struct {
	// Backends is the list of backend URLs to shuffle through.
	Backends []string
	// contains filtered or unexported fields
}

A RandomBackendSelector does a single random shuffle of a list of backends and perpetually returns them in the shuffled order.

RandomBackendSelector is not guaranteed to maintain shuffle order if used by multiple goroutines concurrently.

func (*RandomBackendSelector) Select

func (b *RandomBackendSelector) Select() string

Select returns the next random backend.

type SocketConfig

type SocketConfig struct {
	Host string
	Port int
}

SocketConfig contains the Socket configuration

type StatsdServerConfig

type StatsdServerConfig struct {
	Host          string
	Port          int
	FlushInterval int
	Handlers      []string
	Disable       bool
}

StatsdServerConfig contains the statsd server configuration

type Transformer

type Transformer interface {
	// Transform transforms a metric in a different output metric format to Sensu Metric
	// Format
	Transform() []*types.MetricPoint
}

A Transformer handles transforming Sensu metrics to other output metric formats