health

README

Health Output Plugin

The health plugin provides a HTTP health check resource that can be configured to return a failure status code based on the value of a metric.

When the plugin is healthy it will return a 200 response; when unhealthy it will return a 503 response. The default state is healthy, one or more checks must fail in order for the resource to enter the failed state.

Configuration

# Configurable HTTP health check resource based on metrics
[[outputs.health]]
  ## Address and port to listen on.
  ##   ex: service_address = "http://localhost:8080"
  ##       service_address = "unix:///var/run/telegraf-health.sock"
  # service_address = "http://:8080"

  ## The maximum duration for reading the entire request.
  # read_timeout = "5s"
  ## The maximum duration for writing the entire response.
  # write_timeout = "5s"

  ## Username and password to accept for HTTP basic authentication.
  # basic_username = "user1"
  # basic_password = "secret"

  ## Allowed CA certificates for client certificates.
  # tls_allowed_cacerts = ["/etc/telegraf/clientca.pem"]

  ## TLS server certificate and private key.
  # tls_cert = "/etc/telegraf/cert.pem"
  # tls_key = "/etc/telegraf/key.pem"

  ## One or more check sub-tables should be defined, it is also recommended to
  ## use metric filtering to limit the metrics that flow into this output.
  ##
  ## When using the default buffer sizes, this example will fail when the
  ## metric buffer is half full.
  ##
  ## namepass = ["internal_write"]
  ## tagpass = { output = ["influxdb"] }
  ##
  ## [[outputs.health.compares]]
  ##   field = "buffer_size"
  ##   lt = 5000.0
  ##
  ## [[outputs.health.contains]]
  ##   field = "buffer_size"

compares

The compares check is used to assert basic mathematical relationships. Use it by choosing a field key and one or more comparisons that must hold true. If the field is not found on a metric no comparison will be made.

Comparisons must be hold true on all metrics for the check to pass.

contains

The contains check can be used to require a field key to exist on at least one metric.

If the field is found on any metric the check passes.

Documentation

Index

• type Checker
• type Compares
  • func (c *Compares) Check(metrics []telegraf.Metric) bool
• type Contains
  • func (c *Contains) Check(metrics []telegraf.Metric) bool
• type Health
  • func NewHealth() *Health
  • func (h *Health) Close() error
  • func (h *Health) Connect() error
  • func (h *Health) Init() error
  • func (h *Health) Origin() string
  • func (*Health) SampleConfig() string
  • func (h *Health) ServeHTTP(rw http.ResponseWriter, _ *http.Request)
  • func (h *Health) Write(metrics []telegraf.Metric) error

Types

type Checker

type Checker interface {
	// Check returns true if the metrics meet its criteria.
	Check(metrics []telegraf.Metric) bool
}

type Compares

type Compares struct {
	Field string   `toml:"field"`
	GT    *float64 `toml:"gt"`
	GE    *float64 `toml:"ge"`
	LT    *float64 `toml:"lt"`
	LE    *float64 `toml:"le"`
	EQ    *float64 `toml:"eq"`
	NE    *float64 `toml:"ne"`
}

func (*Compares) Check

func (c *Compares) Check(metrics []telegraf.Metric) bool

type Contains

type Contains struct {
	Field string `toml:"field"`
}

func (*Contains) Check

func (c *Contains) Check(metrics []telegraf.Metric) bool

type Health

type Health struct {
	ServiceAddress string          `toml:"service_address"`
	ReadTimeout    config.Duration `toml:"read_timeout"`
	WriteTimeout   config.Duration `toml:"write_timeout"`
	BasicUsername  string          `toml:"basic_username"`
	BasicPassword  string          `toml:"basic_password"`
	tlsint.ServerConfig

	Compares []*Compares     `toml:"compares"`
	Contains []*Contains     `toml:"contains"`
	Log      telegraf.Logger `toml:"-"`
	// contains filtered or unexported fields
}

func NewHealth

func NewHealth() *Health

func (*Health) Close

func (h *Health) Close() error

Close shuts down the HTTP server.

func (*Health) Connect

func (h *Health) Connect() error

Connect starts the HTTP server.

func (*Health) Init

func (h *Health) Init() error

func (*Health) Origin

func (h *Health) Origin() string

Origin returns the URL of the HTTP server.

func (*Health) SampleConfig

func (*Health) SampleConfig() string

func (*Health) ServeHTTP

func (h *Health) ServeHTTP(rw http.ResponseWriter, _ *http.Request)

func (*Health) Write

func (h *Health) Write(metrics []telegraf.Metric) error

Write runs all checks over the metric batch and adjust health state.