Publish events directly

gcloud

1. Open a terminal.

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

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

   Or:

   gcloud  
   eventarc  
   message-buses  
   publish  
    BUS_NAME 
     
    \ 
     
   --json-message = 
    JSON_MESSAGE 
   

   Or:

   gcloud  
   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  
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  
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

{}