cuckoo

README

Cuckoo

Cuckoo, like the bird in the clock, is a very simple application that polls Consul for a count of healthy instances of a service and posts it to AWS CloudWatch as a metric.

Usage

Use the -help flag to display all the available parameters:

cuckoo -help
  -block duration
        Consul blocking query time (default 10m0s)
  -d    enables debug logging mode
  -metric-name string
        CloudWatch metric data name (default "service_monitoring")
  -metric-namespace string
        CloudWatch metric namespace (default "microservices")
  -service string
        Consul name of the Service to check
  -tag string
        Consul tag of the Service to check
  -version
        print version and exit

The only two required flags are -service and -tag but others exist to tweak preferences. For example:

cuckoo -service voltdb -tag prod

Using the above command will tell Cuckoo to go to Consul and look for all healthy services named voltdb tagged with prod and will post that count number returned from Consul to a CloudWatch metric within the namespace "microservices" and metric data name of "service_monitoring" because these are the default values.

If for example we want to reduce the Consul query blocking time from 10 minutes to 5 we'll need to send the -block flag and the argument with the unit of time. For example:

cuckoo -service voltdb -tag prod -block 5m

There are two environment variables that can be used to set the AWS region in which Cuckoo will post metrics too but if no region is set the default one will be us-east-1

• AWS_DEFAULT_REGION
• AWS_REGION

If Consul is not running in localhost use the default Consul address variable CONSUL_HTTP_ADDR to set for a reachable address

Documentation

Index

• func NewServiceCheck(svcConfig *ServiceCheckConfig) (*serviceCheck, error)
• type ServiceCheckConfig
  • func DefaultServiceCheck() *ServiceCheckConfig

Functions

func NewServiceCheck

func NewServiceCheck(svcConfig *ServiceCheckConfig) (*serviceCheck, error)

newServiceCheck returns a new service check

Types

type ServiceCheckConfig

type ServiceCheckConfig struct {
	Name            string
	Tag             string
	MetricName      string
	MetricNamespace string
	BlockTime       time.Duration
	Logger          *log.Logger
}

serviceCheckConfig is used to represent the configuration of a service check

func DefaultServiceCheck

func DefaultServiceCheck() *ServiceCheckConfig

defaultServiceCheck returns a defaul service check config