Chapter 3. Knative CLI plugins

Prerequisites

• You have installed the Knative (kn) CLI.

Procedure

• Build an event:

  $ kn event build --field <field-name>=<value> --type <type-name> --id <id> --output <format>

  where:

  • The --field flag adds data to the event as a field-value pair. You can use it multiple times.
  • The --type flag enables you to specify a string that designates the type of the event.
  • The --id flag specifies the ID of the event.

  • You can use the json or yaml arguments with the --output flag to change the output format of the event.

    All of these flags are optional.

    Building a simple event

    $ kn event build -o yaml

    Resultant event in the YAML format

    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

    Building a sample transaction event

    $ 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

    Resultant event in the JSON format

    {
      "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="
      }
    }

Prerequisites

• You have installed the Knative (kn) CLI.

Procedure

• Send an event:

  $ kn event send \
    --field <field_name>=<value> \
    --type <type_name> \
    --id <id> \
    --to <url_or_cluster_resource> \
    --namespace <namespace>

  where:

  • The --field flag adds data to the event as a field-value pair. You can use it multiple times.
  • The --type flag enables you to specify a string that designates the type of the event.
  • The --id flag specifies the ID of the event.
  • The --to flag specifies the destination of the event.

  • The --namespace flag specifies the namespace. If omitted, the namespace is taken from the current context.

    All of these flags are optional, except for the destination specification.