Publish events directly

gcloud

1. Open a terminal.

2. You can publish events to a bus by using the gcloud beta eventarc message-buses publish command. For example:

   gcloud beta eventarc message-buses publish BUS_NAME \
       --avro-message=AVRO_MESSAGE

   Or:
   gcloud beta eventarc message-buses publish BUS_NAME \
       --json-message=JSON_MESSAGE

   Or:
   gcloud beta eventarc message-buses publish BUS_NAME \
       --event-data=DATA_PAYLOAD \
       --event-id=EVENT_ID \
       --event-source=EVENT_SOURCE \
       --event-type=EVENT_TYPE \
       --event-attributes=EVENT_ATTRIBUTE

   Replace the following:

   • BUS_NAME: the ID or fully qualified identifier of the bus to which to publish the event.

   You must use only one of the following:

   • AVRO_MESSAGE: the event message in an Avro format according to this specification.
   • JSON_MESSAGE: the event message in a JSON format according to this specification.
   • DATA_PAYLOAD: the data of a published event.

   If using the --event-data flag, you must also use the following:

   • EVENT_ID: the event identifier. Event producers must ensure that source + id is unique for each distinct event.
   • EVENT_SOURCE: the event source of a published event.
   • EVENT_TYPE: the type of event related to the originating occurrence.

   If using the --event-data flag, you can optionally use the following:

   • EVENT_ATTRIBUTE: the attributes of a published event. You can repeat the --event-attributes flag to add more attributes.

     Note that events might include any number of additional custom CloudEvents attributes with distinct names (also known as extension attributes).

Examples:

gcloud beta eventarc message-buses publish my-bus \
    --event-data='{"key": "hello-world-data"}' \
    --event-id=hello-world-id-1234 \
    --event-source=hello-world-source \
    --event-type=hello-world-type \
    --event-attributes="datacontenttype=application/json"

gcloud beta eventarc message-buses publish my-bus --json-message='{
    "specversion" : "1.0",
    "type" :"com.example.someevent",
    "source" : "google.cloud.storage.object.v1.finalized",
    "id" : "A234-1234-1234",
    "time" : "2024-04-05T17:31:00Z",
    "bucket" : "bucketName",
    "datacontenttype" : "application/json",
    "data":{"key": "value"}
}'

REST API

To publish an event to a bus, use the projects.locations.messageBuses.publish method.

Before using any of the request data, make the following replacements:

• The full resource name of the bus in the format projects/PROJECT_ID/locations/LOCATION/messageBuses/BUS_NAME

  Replace the following:

  • PROJECT_ID: the Google Cloud project ID for the bus project.
  • LOCATION: the region in which the bus is deployed—for example, us-central1.
  • BUS_NAME: the name of the bus to which to publish the event.
• SPEC_VERSION: the version of the CloudEvents specification which the event uses—for example, 1.0.
• EVENT_TYPE: the type of event related to the originating occurrence.
• EVENT_SOURCE: the event source of a published event.
• EVENT_ID: the event identifier. Producers must ensure that source + id is unique for each distinct event.
• CONTENT_TYPE (optional): the content type of data value. If a JSON format event has no datacontenttype attribute, then it is assumed that the data is a JSON value conforming to the application/json media type.
• DATA_PAYLOAD (optional): the event payload encoded into the media format specified by datacontenttype and adhering to dataschema when those attributes are present.

Request JSON body:

{
"jsonMessage":
  "{\"specversion\":\"SPEC_VERSION\",
  \"type\":\"EVENT_TYPE\",
  \"source\":\"EVENT_SOURCE\",
  \"id\":\"EVENT_ID\",
  \"datacontenttype\":\"CONTENT_TYPE\",
  \"data\":\"DATA_PAYLOAD\"}"
}

To send your request, expand one of these options:

cat > request.json << 'EOF'
{
"jsonMessage":
  "{\"specversion\":\"SPEC_VERSION\",
  \"type\":\"EVENT_TYPE\",
  \"source\":\"EVENT_SOURCE\",
  \"id\":\"EVENT_ID\",
  \"datacontenttype\":\"CONTENT_TYPE\",
  \"data\":\"DATA_PAYLOAD\"}"
}
EOF

curl -X POST \
     -H "Authorization: Bearer $(gcloud auth print-access-token)" \
     -H "Content-Type: application/json; charset=utf-8" \
     -d @request.json \
     "https://eventarcpublishing.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/messageBuses/BUS_NAME:publish"

@'
{
"jsonMessage":
  "{\"specversion\":\"SPEC_VERSION\",
  \"type\":\"EVENT_TYPE\",
  \"source\":\"EVENT_SOURCE\",
  \"id\":\"EVENT_ID\",
  \"datacontenttype\":\"CONTENT_TYPE\",
  \"data\":\"DATA_PAYLOAD\"}"
}
'@  | Out-File -FilePath request.json -Encoding utf8

$cred = gcloud auth print-access-token
$headers = @{ "Authorization" = "Bearer $cred" }

Invoke-WebRequest `
    -Method POST `
    -Headers $headers `
    -ContentType: "application/json; charset=utf-8" `
    -InFile request.json `
    -Uri "https://eventarcpublishing.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/messageBuses/BUS_NAME:publish" | Select-Object -Expand Content

If successful, the server returns an HTTP 200 OK status code and the empty response body in JSON format:

200 OK

{}