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 and event you should utilize send subcommand. The send command leverages the same builder-like interface as build command does. You could send an event to public address of your application by using --to-url option, or to supported in-cluster resources by using --to option.

Sending to public address

To send event to public address you use --to-url 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-url http://ce-api.foo.example.org/

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

Sending to in-cluster resources

Sending event to in-cluster resources is done with a companion Job that is deployed on your cluster. In that way kn-event and send your event even to resources that are not publicly accessible.

Send an event to a Knative service event-display in namespace default:

$ kn event send \
    --type org.example.kn.ping \
    --id $(uuidgen) \
    --field event.type=test \
    --field event.data=98765 \
    --to Service:serving.knative.dev/v1:event-display

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

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.