Chapter 11. Subscribing functions to CloudEvents
You can subscribe a function to a set of events. This links your function to CloudEvent objects defined by your filters and enables automated responses.
11.1. Subscribing a function to CloudEvents
The subscribe command connects the function to a set of events, matching a series of filters for CloudEvent metadata and a Knative Broker as the source of events, from where they are consumed.
Prerequisites
- You have installed Knative Eventing on the cluster.
- You have configured a Knative Broker.
-
You have installed the Knative (
kn) CLI.
Procedure
Subscribe the function to events for a given broker by running the following command:
Example command
$ kn func subscribe --filter type=com.example.Hello --source my-broker
Use the
--sourceflag to specify the broker and one or more--filterflags to specify your filters.You can also omit the
--sourceflag to use the default broker:Example command
$ kn func subscribe --filter type=com.example --filter extension=my-extension-value
Deploy the function with Knative Triggers:
Example command
$ kn func deploy
Example output
🙌 Function image built: <registry>/hello:latest 🎯 Creating Triggers on the cluster ✅ Function deployed in namespace "default" and exposed at URL: http://hello.default.my-cluster.example.com
