ApiServerSource reference
- ApiServerSource

ApiServerSource reference

This topic provides reference information about the configurable fields for the ApiServerSource object.

ApiServerSource

An ApiServerSource definition supports the following fields:

Field	Description	Required or optional
`apiVersion`	Specifies the API version, for example `sources.knative.dev/v1`.	Required
`kind`	Identifies this resource object as an ApiServerSource object.	Required
`metadata`	Specifies metadata that uniquely identifies the ApiServerSource object. For example, a `name`.	Required
`spec`	Specifies the configuration information for this ApiServerSource object.	Required
`spec.mode`	EventMode controls the format of the event. Set to `Reference` to send a `dataref` event type for the resource being watched. Only a reference to the resource is included in the event payload. Set to `Resource` to have the full resource lifecycle event in the payload. Defaults to `Reference`.	Optional
`spec.owner`	ResourceOwner is an additional filter to only track resources that are owned by a specific resource type. If ResourceOwner matches Resources[n] then Resources[n] is allowed to pass the ResourceOwner filter.	Optional
`spec.resources`	The resources that the source tracks so it can send related lifecycle events from the Kubernetes ApiServer. Includes an optional label selector to help filter.	Required
`spec.serviceAccountName`	The name of the ServiceAccount to use to run this source. Defaults to `default` if not set.	Optional
`spec.sink`	A reference to an object that resolves to a URI to use as the sink.	Required
`spec.ceOverrides`	Defines overrides to control the output format and modifications to the event sent to the sink.	Optional

Owner parameter

ResourceOwner is an additional filter to only track resources that are owned by a specific resource type. If ResourceOwner matches Resources[n] then Resources[n] is allowed to pass the ResourceOwner filter.

An owner definition supports the following fields:

Field	Description	Required or optional
`apiVersion`	API version of the resource to watch.	Required
`kind`	Kind of the resource to watch.	Required

Example: Owner parameter

apiVersion: sources.knative.dev/v1
kind: ApiServerSource
metadata:
 name: <apiserversource>
 namespace: <namespace>
spec:
  ...
  owner:
    apiVersion: apps/v1
    kind: Deployment
  ...

Resources parameter

The resources parameter specifies the resources that the source tracks so that it can send related lifecycle events from the Kubernetes ApiServer. The parameter includes an optional label selector to help filter.

A resources definition supports the following fields:

Field	Description	Required or optional
`apiVersion`	API version of the resource to watch.	Required
`kind`	Kind of the resource to watch.	Required
`selector`	LabelSelector filters this source to objects to those resources pass the label selector.	Optional
`selector.matchExpressions`	A list of label selector requirements. The requirements are ANDed.	Use one of `matchExpressions` or `matchLabels`
`selector.matchExpressions.key`	The label key that the selector applies to.	Required if using `matchExpressions`
`selector.matchExpressions.operator`	Represents a key’s relationship to a set of values. Valid operators are `In`, `NotIn`, `Exists` and `DoesNotExist`.	Required if using `matchExpressions`
`selector.matchExpressions.values`	An array of string values. If `operator` is `In` or `NotIn`, the values array must be non-empty. If `operator` is `Exists` or `DoesNotExist`, the values array must be empty. This array is replaced during a strategic merge patch.	Required if using `matchExpressions`
`selector.matchLabels`	A map of key-value pairs. Each key-value pair in the `matchLabels` map is equivalent to an element of `matchExpressions`, where the key field is `matchLabels.<key>`, the `operator` is `In`, and the `values` array contains only “matchLabels.“. The requirements are ANDed.	Use one of `matchExpressions` or `matchLabels`

Example: Resources parameter

Given the following YAML, the ApiServerSource object receives events for all Pods and Deployments in the namespace:

apiVersion: sources.knative.dev/v1
kind: ApiServerSource
metadata:
  name: <apiserversource>
  namespace: <namespace>
spec:
  # ...
  resources:
    - apiVersion: v1
      kind: Pod
    - apiVersion: apps/v1
      kind: Deployment

Example: Resources parameter using matchExpressions

Given the following YAML, ApiServerSource object receives events for all Pods in the namespace that have a label app=myapp or app=yourapp:

apiVersion: sources.knative.dev/v1
kind: ApiServerSource
metadata:
  name: <apiserversource>
  namespace: <namespace>
spec:
  # ...
  resources:
    - apiVersion: v1
      kind: Pod
      selector:
        matchExpressions:
          - key: app
            operator: In
            values:
              - myapp
              - yourapp

Example: Resources parameter using matchLabels

Given the following YAML, the ApiServerSource object receives events for all Pods in the namespace that have a label app=myapp:

apiVersion: sources.knative.dev/v1
kind: ApiServerSource
metadata:
  name: <apiserversource>
  namespace: <namespace>
spec:
  # ...
  resources:
    - apiVersion: v1
      kind: Pod
      selector:
        matchLabels:
          app: myapp

Sink parameter

Sink is a reference to an object that resolves to a URI to use as the sink.

A sink definition supports the following fields:

Field	Description	Required or optional
`ref`	This points to an Addressable.	Required if not using `uri`
`ref.apiVersion`	API version of the referent.	Required if using `ref`
`ref.kind`	Kind of the referent.	Required if using `ref`
`ref.namespace`	Namespace of the referent. If omitted this defaults to the object holding it.	Optional
`ref.name`	Name of the referent.	Required if using `ref`
`uri`	This can be an absolute URL with a non-empty scheme and non-empty host that points to the target or a relative URI. Relative URIs are resolved using the base URI retrieved from Ref.	Required if not using `ref`

Note

At least one of ref or uri is required. If both are specified, uri is resolved into the URL from the Addressable ref result.

Example: Sink parameter

Given the following YAML, if ref resolves into "http://mysink.default.svc.cluster.local", then uri is added to this resulting in "http://mysink.default.svc.cluster.local/extra/path".

apiVersion: sources.knative.dev/v1
kind: ApiServerSource
metadata:
 name: <apiserversource>
 namespace: <namespace>
spec:
  ...
  sink:
    ref:
      apiVersion: v1
      kind: Service
      namespace: default
      name: mysink
    uri: /extra/path

Contract

This results in the K_SINK environment variable being set on the sink container as "http://mysink.default.svc.cluster.local/extra/path".

CloudEvent Overrides

CloudEvent Overrides defines overrides to control the output format and modifications of the event sent to the sink.

A ceOverrides definition supports the following fields:

Field	Description	Required or optional
`extensions`	Specifies which attributes are added or overridden on the outbound event. Each `extensions` key-value pair is set independently on the event as an attribute extension.	Optional

Note

Only valid CloudEvent attribute names are allowed as extensions. You cannot set the spec defined attributes from the extensions override configuration. For example, you can not modify the type attribute.

Example: CloudEvent Overrides

apiVersion: sources.knative.dev/v1
kind: ApiServerSource
metadata:
 name: <apiserversource>
 namespace: <namespace>
spec:
  ...
  ceOverrides:
    extensions:
      extra: this is an extra attribute
      additional: 42

Contract

This results in the K_CE_OVERRIDES environment variable being set on the sink container as follows:

{ "extensions": { "extra": "this is an extra attribute", "additional": "42" } }