Skip to content

Latest commit

 

History

History
161 lines (146 loc) · 5.95 KB

API.md

File metadata and controls

161 lines (146 loc) · 5.95 KB
Raw

1.0.0 API Reference

Commands

Flags need to be formatted as -<key1>=<value1>,-<key2>=<value2>,...-<keyn>=<valuen>.

Required Flags

  • -kapacitorurl - set the url to the kapacitord server. Needs to include the schema, host and port values. eg: http://localhost:9092

Optional Flags

  • -incluster - configure the context of where this controller is to run. If it is inside a Kubernetes cluster, safe defaults will be used to fetch API data from environment variables.
  • -cleansubscriptions - enable influx subscription cleanup
  • -influxurl - set the url to the influxd server. Needs to include the schema, host and port values. eg: http://localhost:8086
  • -influxusername - set the username for influx connection
  • -influxpassword - set the password for the influx connection
  • -influxssl - set the http schema through this property
  • -influxunsafessl - skip ssl verification
  • -kubeconfig - path to the kubectl configuration file.
  • -prefixname - a custom prefix string to use for filtering ConfigMaps coming from the Kubernetes API
  • -loglevel - a value of 0-5 for capturing panic -> debug log messages.

ConfigMap

The configuration is loosely based off of the kapacitor define <task> -vars vars.json file contract located here.

Contract

kind: ConfigMap
apiVersion: v1
metadata:
  name: kapacitor-hpa-rule-{config-map-name}
  namespace: eng
data:
  # default tick template
  template: >-
    { "type" : "string", "value" : "autoscaling" }
  # target is the desired number of request per second per host
  target: >-
    { "type" : "float", "value" : 11 }
  # only one scaling event will be triggered by this time interval
  # https://docs.influxdata.com/kapacitor/v1.3/tick/syntax/#durations
  scalingCooldown: >-
    { "type" : "duration", "value" : "1m0s" }
  # only one descaling even twill be triggered by this time interval
  # https://docs.influxdata.com/kapacitor/v1.3/tick/syntax/#durations
  descalingCooldown: >-
    { "type" : "duration", "value" : "2m0s" }
  # database
  database: >-
    { "type" : "string", "value" : "telegraf" }
  # retention policy for database
  retentionPolicy: >-
    { "type" : "string", "value" : "2-weeks" }
  # dataset collected within the retention policy
  measurement: >-
    { "type" : "string", "value" : "docker_container_cpu" }
  # filter dataset for only preproduction data
  where_filter: >-
    { "type" : "lambda", "value" : "\"environment\" == 'preproduction'" }
  # data to be used for comparison with target
  field: >-
    { "type" : "string", "value" : "usage_percent" }
  # namespace deployment resides
  namespace: >-
    { "type" : "string", "value" : "{deployment-namespace}" }
  # name of deployment to scale for
  deploymentName: >-
    { "type" : "string", "value" : "{deployment-name}" }
  # name of release
  releaseName: >-
    { "type" : "string", "value" : "{release-name}" }
  # minimum amount of replicas running >-
  minReplicaCount: >-
    { "type" : "int", "value" : 1 }    
  # maximum amount of replicas running >-
  maxReplicaCount: >-
    { "type" : "int", "value" : 20 }

Replacement Tokens

  • {config-map-name} - name appending the kapacitor-hpa-rule- prefix.
  • {release-name} - release name issued from helm if given, or something arbitrary associated to the application.
  • {deployment-namespace} - namespace the deployment resides in
  • {deployment-name} - must be the same name registered with the ReplicateSet. This is the key used to target the replicaCount change within the TICK script.

TICK

autoscaling

This script is combined with the ConfigMap to scale up/down a replicate set based on collected data available from InfluxDB. We can assume all measurements are available based on any telegraf forwarded telemetry along with your own custom data points pushed.

// Database
var database string
// Retention policy for database
var retentionPolicy string
// Dataset collected within the retention policy
var measurement string
// Optional where filter
var whereFilter = lambda: TRUE
// Field data to use for the processing
var field string
// The time scale to calculate the average against
var movingAverageCount = 60
// Namespace the deployment lives in
var namespace = 'default'
// Deployment this is scaling for
var deploymentName = 'placeholder'
// Threshold for triggering
var target = 10.0
// Time interval per scaling up
var scalingCooldown = 2m
// Time interval per scaling down
var descalingCooldown = 5m
// Minimum replica count to maintain regardless of needs
var minReplicaCount = 1
// Maximum replica count to stop scaling at regardless of needs
var maxReplicaCount = 20
	
stream
	|from()
		.database(database)
		.retentionPolicy(retentionPolicy)
		.measurement(measurement)
		.where(whereFilter)
		.truncate(1s)
	|movingAverage(field, movingAverageCount)
		.as('averageResource')	
	|eval(lambda: int(ceil("averageResource" / float(target))))
		.as('replicaCount')
	|k8sAutoscale()
		// We are scaling a deployment.
		.kind('deployments')
		// The namespace of the deployment
		.namespace(namespace)
		// The name of the replicaset to scale is found in the 'replicaset' tag.
		.resourceName(deploymentName)
		// Set the cool down timer values.
		.increaseCooldown(scalingCooldown)
		.decreaseCooldown(descalingCooldown)
		// The minimum amount of replica to have regardless of averages
		.min(minReplicaCount)
		// The maximum amount of replica to have regardless of averages
		.max(maxReplicaCount)
		// Compute the desired number of replicas based on the
		// avg_point_per_second and target values.
		.replicas(lambda: "replicaCount")