SinkBinding reference
This topic provides reference information about the configurable parameters for SinkBinding objects.
Supported parameters
A SinkBinding
resource supports the following parameters:
Field | Description | Required or optional |
---|---|---|
apiVersion | Specifies the API version, for example sources.knative.dev/v1 . | Required |
kind | Identifies this resource object as a SinkBinding object. | Required |
metadata | Specifies metadata that uniquely identifies the SinkBinding object. For example, a name . | Required |
spec | Specifies the configuration information for this SinkBinding object. | Required |
spec.sink | A reference to an object that resolves to a URI to use as the sink. | Required |
spec.subject | A reference to the resources for which the “runtime contract” is augmented by Binding implementations. | Required |
spec.ceOverrides | Defines overrides to control the output format and modifications to the event sent to the sink. | Optional |
Subject parameter
The Subject parameter references the resources for which the “runtime contract” is augmented by Binding implementations.
A subject
definition supports the following fields:
Field | Description | Required or optional |
---|---|---|
apiVersion | API version of the referent. | Required |
kind | Kind of the referent. | Required |
namespace | Namespace of the referent. If omitted, this defaults to the object holding it. | Optional |
name | Name of the referent. | Do not use if you configure selector . |
selector | Selector of the referents. | Do not use if you configure name . |
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. | Use one of matchExpressions or matchLabels |
Subject parameter examples
Given the following YAML, the Deployment
named mysubject
in the default
namespace is selected:
apiVersion: sources.knative.dev/v1
kind: SinkBinding
metadata:
name: bind-heartbeat
spec:
subject:
apiVersion: apps/v1
kind: Deployment
namespace: default
name: mysubject
...
Given the following YAML, any Job
with the label working=example
in the default
namespace is selected:
apiVersion: sources.knative.dev/v1
kind: SinkBinding
metadata:
name: bind-heartbeat
spec:
subject:
apiVersion: batch/v1
kind: Job
namespace: default
selector:
matchLabels:
working: example
...
Given the following YAML, any Pod
with the label working=example
OR working=sample
in the default
namespace is selected:
apiVersion: sources.knative.dev/v1
kind: SinkBinding
metadata:
name: bind-heartbeat
spec:
subject:
apiVersion: v1
kind: Pod
namespace: default
selector:
- matchExpression:
key: working
operator: In
values:
- example
- sample
...
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.
CloudEvent Overrides example
apiVersion: sources.knative.dev/v1
kind: SinkBinding
metadata:
name: bind-heartbeat
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 subject
as follows:
{ "extensions": { "extra": "this is an extra attribute", "additional": "42" } }