check

README

package check

This package is responsible of defining the types representing an agent check along with an interface implemented by the code responsible to create a check instance based on an existing configuration.

Check Loaders

Loaders implement the CheckLoader interface, they are responsible to instantiate one object of type check.Check for every configuration instance within a integration.Config object. A Loader usually invokes the Configure method on check objects passing in the configuration instance in YAML format: how to use it, it's up to the check itself.

Usage example:

// given a list of configurations, try to load corresponding checks using different loaders
checks := []check.Check{}
for _, conf := range configs {
  for _, loader := range loaders {
    res, err := loader.Load(conf)
    if err == nil {
      checks = append(checks, res...)
    }
  }
}
// `checks` contains one check per configuration instance found.

Documentation

Index

• func CollectDefaultMetrics(c integration.Config) bool
• func IDToCheckName(id ID) string
• func IsJMXConfig(name string, initConf integration.Data) bool
• func Retry(retryDuration time.Duration, retries int, callback func() error, ...) (err error)
• type Check
• type ID
  • func BuildID(checkName string, instance, initConfig integration.Data) ID
  • func Identify(check Check, instance integration.Data, initConfig integration.Data) ID
• type Loader
• type RetryableError
  • func (e RetryableError) Error() string
• type Stats
  • func NewStats(c Check) *Stats
  • func (cs *Stats) Add(t time.Duration, err error, warnings []error, metricStats map[string]int64)

Functions

func CollectDefaultMetrics

func CollectDefaultMetrics(c integration.Config) bool

CollectDefaultMetrics returns if the config is for a JMX check which has collect_default_metrics: true

func IDToCheckName

func IDToCheckName(id ID) string

IDToCheckName returns the check name from a check ID

func IsJMXConfig

func IsJMXConfig(name string, initConf integration.Data) bool

IsJMXConfig checks if a certain YAML config is a JMX config

func Retry

func Retry(retryDuration time.Duration, retries int, callback func() error, friendlyName string) (err error)

Retry retries a callback up to `retries`-times in a `retryDuration` period of time, and bails out if the limit is reached.

Types

type Check

type Check interface {
	Run() error                                          // run the check
	Stop()                                               // stop the check if it's running
	String() string                                      // provide a printable version of the check name
	Configure(config, initConfig integration.Data) error // configure the check from the outside
	Interval() time.Duration                             // return the interval time for the check
	ID() ID                                              // provide a unique identifier for every check instance
	GetWarnings() []error                                // return the last warning registered by the check
	GetMetricStats() (map[string]int64, error)           // get metric stats from the sender
	Version() string                                     // return the version of the check if available
}

Check is an interface for types capable to run checks

type ID

type ID string

ID is the representation of the unique ID of a Check instance

func BuildID

func BuildID(checkName string, instance, initConfig integration.Data) ID

BuildID returns an unique ID for a check name and its configuration

func Identify

func Identify(check Check, instance integration.Data, initConfig integration.Data) ID

Identify returns an unique ID for a check and its configuration

type Loader

type Loader interface {
	Load(config integration.Config) ([]Check, error)
}

Loader is the interface wrapping the operations to load a check from different sources, like Python modules or Go objects.

A check is loaded for every `instance` found in the configuration file. Load is supposed to break down instances and return different checks.

type RetryableError

type RetryableError struct {
	Err error
}

RetryableError is the error type that Retry interprets as a request to retry the callback

func (RetryableError) Error

func (e RetryableError) Error() string

type Stats

type Stats struct {
	CheckName            string
	CheckVersion         string
	CheckID              ID
	TotalRuns            uint64
	TotalErrors          uint64
	TotalWarnings        uint64
	MetricSamples        int64
	Events               int64
	ServiceChecks        int64
	TotalMetricSamples   int64
	TotalEvents          int64
	TotalServiceChecks   int64
	ExecutionTimes       [32]int64 // circular buffer of recent run durations, most recent at [(TotalRuns+31) % 32]
	AverageExecutionTime int64     // average run duration
	LastExecutionTime    int64     // most recent run duration, provided for convenience
	LastError            string    // error that occurred in the last run, if any
	LastWarnings         []string  // warnings that occurred in the last run, if any
	UpdateTimestamp      int64     // latest update to this instance, unix timestamp in seconds
	// contains filtered or unexported fields
}

Stats holds basic runtime statistics about check instances

func NewStats

func NewStats(c Check) *Stats

NewStats returns a new check stats instance

func (*Stats) Add

func (cs *Stats) Add(t time.Duration, err error, warnings []error, metricStats map[string]int64)

Add tracks a new execution time