kn-plugin-event

kn-plugin-event is a plugin of Knative Client, for managing cloud events from command line.

Description

With this plugin, you can build and send the cloud events to publicly available addresses (URLs) or to Addressable (Kubernetes service, Knative service, broker, channels, etc) inside of Kubernetes cluster.

Usage

Build an event

You could use build subcommand to create an event with a help of convenient builder-like interface. It may be helpful to send that even later or use it in other context.

Simplest event

$ kn event build -o yaml
data: {}
datacontenttype: application/json
id: 81a402a2-9c29-4c27-b8ed-246a253c9e58
source: kn-event/v0.4.0
specversion: "1.0"
time: "2021-10-15T10:42:57.713226203Z"
type: dev.knative.cli.plugin.event.generic

More complex example

$ kn event build \
    --field operation.type=local-wire-transfer \
    --field operation.amount=2345.40 \
    --field operation.from=87656231 \
    --field operation.to=2344121 \
    --field automated=true \
    --field signature='FGzCPLvYWdEgsdpb3qXkaVp7Da0=' \
    --type org.example.bank.bar \
    --id $(head -c 10 < /dev/urandom | base64 -w 0) \
    --output json
{
  "specversion": "1.0",
  "id": "RjtL8UH66X+UJg==",
  "source": "kn-event/v0.4.0",
  "type": "org.example.bank.bar",
  "datacontenttype": "application/json",
  "time": "2021-10-15T10:43:23.113187943Z",
  "data": {
    "automated": true,
    "operation": {
      "amount": "2345.40",
      "from": 87656231,
      "to": 2344121,
      "type": "local-wire-transfer"
    },
    "signature": "FGzCPLvYWdEgsdpb3qXkaVp7Da0="
  }
}

Send an event

To send an event, you should use the send subcommand. The send command uses the same builder-like interface as the build command. You can send an event to the public address of your application or to a supported in-cluster resource by using the --to option.

Sending to a public address

To send an event to a public address, you should pass the address to the --to option:

$ kn event send \
    --field player.id=6354aa60-ddb1-452e-8c13-24893667de20 \
    --field player.game=2345 \
    --field points=456 \
    --type org.example.gaming.foo \
    --to http://ce-api.foo.example.org/

NOTE: All arguments, except --to are optional. Use kn event send --help to see full usage information.

Sending to the in-cluster resources

Sending events to the in-cluster resources is done with a companion Job that is deployed on your cluster. This allows kn-event to send your events to resources that are not publicly accessible.

Send an event to a Knative service showcase in current namespace:

$ kn event send \
    --type org.example.kn.ping \
    --id $(uuidgen) \
    --field event.data=98765 \
    --to showcase

To send the event to the broker named foo in my-ns namespace:

$ kn event send --to broker:foo:my-ns

NOTE: The --to option follows the Kn sink format. Use kn event send --help to see full format description.

Install

You can download a pre-built version of kn-plugin-event from our release page . Choose the one that fits your platform.

When the download is ready, you should be ready to use kn-plugin-event as a standalone binary. Check the available commands with:

kn-event-<OS>-<ARCH> --help

Install to work with kn CLI

If you'd like to use the plugin with kn CLI, install the plugin by simply copying the executable file under kn plugins directory as:

$ mkdir -p ~/.config/kn/plugins
$ cp build/_output/bin/kn-event-<OS>-<ARCH> \
    ~/.config/kn/plugins/kn-event

Check if plugin is loaded

$ kn -h

Run it

$ kn event -h

Building

If you'd like to build the plugin yourself, you will need to have Golang installed on your machine. Check the go.mod file for current minimum version.

To build the plugin, just invoke the following script:

$ ./mage

Project will check, test and build binaries for various platforms. You'll get an executable plugin binary named kn-event-<OS>-<ARCH> in build/_output/bin dir.

You could list all available build targets with:

$ ./mage -l

Updating dependencies

To update dependencies, please utilize the standard hack/update-deps.sh script. It's also needed to run this script if you are doing any changes to Go libraries. Read more about it at knative/hack repository.