OpenStack Metric Latest

Scale applications based on a threshold reached by a specific measure from OpenStack Metric API.

Availability: v2.3+ Maintainer: Community

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Trigger Specification

This specification describes the openstack-metric trigger for OpenStack metrics.

The OpenStack metric API follows Gnocchi API. Attempt to the fact that Gnocchi API is an open-source time series database embedded in OpenStack system and every parameter on OpenStack Metric API follows its patterns but you don’t need to reference anything from Gnocchi. It scales based on a specific measure from a given resource metric. It’s highly recommended to check Gnocchi docs.

triggers:
- type: openstack-metric
  metadata:
    metricsURL: http://localhost:8041/v1/metric #required
    metricID: 003bb589-166d-439d-8c31-cbf098d863de #required
    aggregationMethod: "mean" #required
    granularity: 300 #required (seconds)
    threshold: 1250 #required
    timeout: 30 #optional

Protocol (http or https) should always be provided when specifying URLs

Parameter list:

  • metricsURL - The URL to check for the metrics API, based. It must contain the hostname, the metric port, the API version, and the resource ID. The pattern is: http://<host>:<metric_port>/<openstack_metric_api_version>/<resource_id>/metric
  • metricID - The Id of the intendend metric
  • aggregationMethod - The aggregation method that will be used to calculate metrics, it must follows the configured possible metrics derived from gnocchi API like: mean, min, max, std, sum, count, the complete aggregation methods list can be found here.
  • granularity - The configured granularity from metric collection in seconds. it must follow the same value configured in OpenStack, but it must be coutned in seconds. Sample: If you have a 5 minutes time window granularity defined, so you must input a value of 300 seconds (5*60).
  • threshold - The target value that, when reached, will scale the application.
  • timeout - The timeout, in seconds, for the HTTP client requests that will query the Metric API. If not specified, the default value is 30 seconds. This must be an integer value. If 0 or negative value is provided it defaults to 300 milliseconds.

Authentication Parameters

To authenticate, this scaler uses tokens. Tokens are automatically retrieved by the scaler from Keystone, the official OpenStack Identity Provider. You can provide your credentials using Secrets either by using the “password” method or the “application credentials” method. Both cases use TriggerAuthentication.

Password

  • authURL - The Keystone authentication URL. The pattern is: http://<host>:<keystone_port>/<keystone_version>/
  • userID - The OpenStack project user ID
  • password - The password for the provided user
  • projectID - The OpenStack project ID

Application Credentials

  • authURL - The Keystone authentication URL. The pattern is: http://<host>:<keystone_port>/<keystone_version>/
  • appCredentialID - The Application Credential ID
  • appCredentialSecret - The Application Credential secret

Example

Password method

Here is an example of how to deploy a scaled object with the openstack-metric scale trigger which uses TriggerAuthentication and the Password method from above.

apiVersion: v1
kind: Secret
metadata:
  name: openstack-secret-password
  namespace: default
type: Opaque
data:
  authURL: aHR0cDovL2xvY2FsaG9zdDo1MDAwL3YzLw==
  userID: MWYwYzI3ODFiNDExNGQxM2E0NGI4ODk4Zjg1MzQwYmU=
  password: YWRtaW4=
  projectID: YjE2MWRjNTE4Y2QyNGJkYTg0ZDk0ZDlhMGU3M2ZjODc=
---
apiVersion: keda.sh/v1alpha1
kind: TriggerAuthentication
metadata:
  name: metrics-password-trigger-authentication
  namespace: default
spec:
  secretTargetRef:
  - parameter: authURL
    name: openstack-secret-password
    key: authURL
  - parameter: userID
    name: openstack-secret-password
    key: userID
  - parameter: password
    name: openstack-secret-password
    key: password
  - parameter: projectID
    name: openstack-secret-password
    key: projectID
---
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: openstack-metric-scaledobject
  namespace: default
spec:
  scaleTargetRef:
    name: my-deployment
  pollingInterval: 10
  cooldownPeriod: 10
  minReplicaCount: 0
  triggers:
  - type: openstack-metric
    metadata:
      metricsURL: http://localhost:8041/v1/metric 
      metricID: faf01aa5-da88-4929-905d-b83fbab46771
      aggregationMethod: "mean"
      granularity: 300 
      threshold: 1250 
      timeout: 30 
    authenticationRef:
        name: openstack-metric-password-trigger-authentication

Application Credentials method

You can also use the Application Credentials method.

apiVersion: v1
kind: Secret
metadata:
  name: openstack-secret-appcredentials
  namespace: default
type: Opaque
data:
  authURL: aHR0cDovL2xvY2FsaG9zdDo1MDAwL3YzLw==
  appCredentialID: OWYyY2UyYWRlYmFkNGQxNzg0NTgwZjE5ZTljMTExZTQ=
  appCredentialSecret: LVdSbFJBZW9sMm91Z3VmZzNEVlBqcll6aU9za1pkZ3c4Y180XzRFU1pZREloT0RmajJkOHg0dU5yb3NudVIzWmxDVTZNLTVDT3R5NDFJX3M5R1N5Wnc=
---
apiVersion: keda.sh/v1alpha1
kind: TriggerAuthentication
metadata:
  name: openstack-metric-appcredentials-trigger-authentication
  namespace: default
spec:
  secretTargetRef:
  - parameter: authURL
    name: openstack-secret-appcredentials
    key: authURL
  - parameter: appCredentialID
    name: openstack-secret-appcredentials
    key: appCredentialID
  - parameter: appCredentialSecret
    name: openstack-secret-appcredentials
    key: appCredentialSecret
---
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: openstack-metric-scaledobject
  namespace: default
spec:
  scaleTargetRef:
    name: my-deployment
  pollingInterval: 10
  cooldownPeriod: 10
  minReplicaCount: 0
  triggers:
  - type: openstack-metric
    metadata:
       metricsURL: http://localhost:8041/v1/metric 
      metricID: faf01aa5-da88-4929-905d-b83fbab46771
      aggregationMethod: "mean"
      granularity: 300 
      threshold: 1250
    authenticationRef:
        name: openstack-metric-appcredentials-trigger-authentication


Currently available scalers for KEDA