Publish
ClearBlade uses the Pub/Sub Golang library, which leverages a persistent TCP connection under the covers.
...
| Code Block |
|---|
{
"credentials_map": { // This is the service account JSON object
"type": "service_account",
"project_id": "myprojectid",
"private_key_id": "blahblahblah",
"private_key": "<priv_key>",
"client_email": "a@a.com",
"client_id": "9126871624161341",
"auth_uri": "https://accounts.google.com/o/oauth2/auth",
"token_uri": "https://oauth2.googleapis.com/token",
"auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
"client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/dahjkdhajkd%40dajsdgajdadsad.iam.gserviceaccount.com"
},
"project_id": "myprojectid",
"topics": [ // This is to send data to Google Pub/Sub
{"path": "iotdemo"}, // Non IoT Core topic
{"path": "/devices/+/events", "type": 1, "target": "performance-testing"}, // IoT Core topic
{"path": "/devices/+/events/sub", "type": 1, "target": "performance-testing-sub", "sub_folder": "sub"}, // iot core topic
{"path": "/devices/+/state", "type": 2, "target": "performance-testing-state"} // IoT Core topic
],
"forwarders": { // This is to receive Google Pub/Sub messages
"ack_strategy": 0,
"poll_rate": 5000,
"max_messages_per_poll": 2,
"subscriptions": [
{
"mqtt_topic": "pubsub",
"pubsub_subscription": "test-sub"
}
]
},
} |
path is the topic the Pub/Sub client will subscribe to internally to the ClearBlade broker. type is the topic type. No type represents a non-IoT Core topic. 1 is for event and 2 is for state. target is the topic the Pub/Sub client will publish to in Pub/Sub. sub_folder is for the event's topic if it has a subfolder.
...
GET and DELETE support only. GET obtains all Pub/Sub connections for that system, and DELETE deletes all.
Receiving data
The following parameters exist for setting up your Google Pub/Sub forwarders to ClearBlade MQTT:
ack_strategy: 0 = ack immediately, 1 = never ack. for now, 0 should always be used
poll_rate: time (ms) between sending message batches to the broker. zero will send messages immediately.
max_messages_per_poll: max number of messages to send in a single batch to the broker. implicit minimum value of 1
Messages are received by ClearBlade as soon as possible from Google. ClearBlade will buffer them up internally and send in batches as defined above.