Trigger Specification

This specification describes the azure-monitor trigger that scales based on an Azure Monitor metric.

triggers:
- type: azure-monitor
  metadata:
    resourceURI: Microsoft.ContainerService/managedClusters/azureMonitorCluster
    tenantId: xxx-xxx-xxx-xxx-xxx
    subscriptionId: yyy-yyy-yyy-yyy-yyy
    resourceGroupName: azureMonitor
    metricName: kube_pod_status_ready
    metricFilter: namespace eq 'default'
    metricAggregationInterval: "0:1:0"
    targetValue: "0.5"
    activationTargetValue: "3.5"
    activeDirectoryClientId: <client id value> # Optional, can use TriggerAuthentication as well
    activeDirectoryClientIdFromEnv: CLIENT_ID_ENV_NAME # Optional, can use TriggerAuthentication as well
    activeDirectoryClientPasswordFromEnv: CLIENT_PASSWORD_ENV_NAME # Optional, can use TriggerAuthentication as well
    # Optional (Default: AzurePublicCloud)
    cloud: Private
    # Required when cloud = Private
    azureResourceManagerEndpoint: https://management.azure.airgap.com/
    # Required when cloud = Private.
    activeDirectoryEndpoint: https://login.airgap.example/

Parameter list:

• resourceURI - Shortened URI to the Azure resource with format "<resourceProviderNamespace>/<resourceType>/<resourceName>".
• tenantId - Id of the tenant that contains the Azure resource. This is used for authentication.
• subscriptionId - Id of Azure subscription that contains the Azure resource. This is used for determining the full resource URI.
• resourceGroupName - Name of the resource group for the Azure resource.
• metricName - Name of the metric to query.
  • Azure metrics are available as a list in the official documentation.
  • Custom metric name when querying Azure Monitor custom metrics.
• metricNamespace - Name of the metric namespace. Required when metricName is a custom metric.
• targetValue - Target value to trigger scaling actions. (This value can be a float)
• activationTargetValue - Target value for activating the scaler. Learn more about activation here.(Default: 0, Optional, This value can be a float)
• metricAggregationType - Aggregation method of the Azure Monitor metric. Options include Average, Total, Maximum with a full list in the official documentation.
• metricFilter - Name of the filter to be more specific by using dimensions listed in the official documentation. (Optional)
• metricAggregationInterval - Collection time of the metric in format "hh:mm:ss" (Default: "0:5:0", Optional)
• activeDirectoryClientId - Id of the Active Directory application which requires at least Monitoring Reader permissions. (Optional)
• activeDirectoryClientPasswordFromEnv - Name of the environment variable that contains the active directory client password. (Optional)
• cloud - Name of the cloud environment that the Azure resource belongs to. (Values: AzurePublicCloud, AzureUSGovernmentCloud, AzureGermanCloud, AzureChinaCloud, Private, Default: AzurePublicCloud, Optional)
• azureResourceManagerEndpoint - Azure Resource Manager endpoint of the cloud environment. (Required when cloud is set to Private, e.g. https://management.chinacloudapi.cn/ for AzureChinaCloud).
• activeDirectoryEndpoint - Active Directory endpoint of the cloud environment. (Required when cloud is set to Private, e.g. https://login.chinacloudapi.cn/ for AzureChinaCloud).

Some parameters could be provided using environmental variables, instead of setting them directly in metadata. Here is a list of parameters you can use to retrieve values from environment variables:

• activeDirectoryClientIdFromEnv - Id of the Active Directory application which requires at least Monitoring Reader permissions, similar to activeDirectoryClientId, but reads it from an environment variable on the scale target. (Optional)

Authentication Parameters

You can use TriggerAuthentication CRD to configure the authentication by providing a set of Azure Active Directory credentials or by using pod identity.

Credential based authentication:

• activeDirectoryClientId - Id of the Active Directory application which requires at least Monitoring Reader permissions.
• activeDirectoryClientPassword - Password of the Active Directory application.

The user will need access to read data from the Azure resource.

Pod identity based authentication:

Azure AD Workload Identity provider can be used.

Example

apiVersion: v1
kind: Secret
metadata:
  name: azure-monitor-secrets
data:
  activeDirectoryClientId: <clientId>
  activeDirectoryClientPassword: <clientPassword>
---
apiVersion: keda.sh/v1alpha1
kind: TriggerAuthentication
metadata:
  name: azure-monitor-trigger-auth
spec:
  secretTargetRef:
    - parameter: activeDirectoryClientId
      name: azure-monitor-secrets
      key: activeDirectoryClientId
    - parameter: activeDirectoryClientPassword
      name: azure-monitor-secrets
      key: activeDirectoryClientPassword
  # or Pod Identity, kind: Secret is not required in case of pod Identity
  podIdentity:
      provider: azure-workload
---
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: azure-monitor-scaler
spec:
  scaleTargetRef:
    name: azure-monitor-example
  minReplicaCount: 1
  maxReplicaCount: 10
  triggers:
  - type: azure-monitor
    metadata:
      resourceURI: Microsoft.ContainerService/managedClusters/azureMonitorCluster
      tenantId: xxx-xxx-xxx-xxx-xxx
      subscriptionId: yyy-yyy-yyy-yyy-yyy
      resourceGroupName: azureMonitor
      metricName: pod_custom_metric
      metricNamespace: pod_custom_metrics_namespace # required when monitoring custom metrics
      metricFilter: namespace eq 'default'
      metricAggregationInterval: "0:1:0"
      metricAggregationType: Average
      targetValue: "1"
    authenticationRef:
      name: azure-monitor-trigger-auth