predicate filter action Predicate Filter Action

Provided by: "Apache Software Foundation"

Support Level for this Kamelet is: "Preview"

Filter based on a JsonPath Expression

Configuration Options

The following table summarizes the configuration options available for the predicate-filter-action Kamelet:

Property Name Description Type Default Example

expression *

Expression

The JsonPath Expression to evaluate, without the external parenthesis. Since this is a filter, the expression will be a negation, this means that if the foo field of the example is equals to John, the message will go ahead, otherwise it will be filtered out.

string

"@.foo =~ /.*John/"

Fields marked with (*) are mandatory.

Usage

This section summarizes how the predicate-filter-action can be used in various contexts.

Knative Action

The predicate-filter-action Kamelet can be used as intermediate step in a binding.

predicate-filter-action-binding.yaml
apiVersion: camel.apache.org/v1alpha1
kind: KameletBinding
metadata:
  name: predicate-filter-action-binding
spec:
  source:
    ref:
      kind: Kamelet
      apiVersion: camel.apache.org/v1alpha1
      name: timer-source
    properties:
      message: "Hello"
  steps:
  - ref:
      kind: Kamelet
      apiVersion: camel.apache.org/v1alpha1
      name: predicate-filter-action
    properties:
      expression: "@.foo =~ /.*John/"
  sink:
    ref:
      kind: InMemoryChannel
      apiVersion: messaging.knative.dev/v1
      name: mychannel

Make sure you have Camel K installed into the Kubernetes cluster you’re connected to.

Save the predicate-filter-action-binding.yaml file into your hard drive, then configure it according to your needs.

You can run the action using the following command:

kubectl apply -f predicate-filter-action-binding.yaml