This example shows how to use the WebSocket API to connect to a Pulsar cluster and then produce and consume messages to and from the Pulsar cluster.
  • This document assumes that you have created a service account, and have granted the service account produce and consume permissions to the namespace for the target topic.
  • To use the WebSocket API to connect to a Pulsar cluster, you need to enable the WebSocket service in advance. For details, see enable WebSocket service.
  • If Web Socket Secure (WSS) protocol is used, you should use the port 9443.

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Prerequisites

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Steps

  1. Connect to the Pulsar cluster. 
    import websocket, base64, json

# TOPIC = 'ws://CLUSTER_HOST:9090/ws/v2/consumer/persistent/public/default/test/sub'
TOPIC = 'wss://CLUSTER_HOST:9443/ws/v2/consumer/persistent/public/default/test/sub'
token = "YOUR_TOKEN"
header = ["Authorization:Bearer" + token]
ws = websocket.create_connection(TOPIC, header=header)
while True:
  msg = json.loads(ws.recv())
  if not msg: break
  print("Received: {} - payload: {}".format(msg, base64.b64decode(msg['payload'])))
  # Acknowledge successful processing
  ws.send(json.dumps({'messageId' : msg['messageId']}))

ws.close()
    Replace the CLUSTER_HOST parameter with the domain name of the cluster.
  2. Create a consumer and use the consumer to consume messages. 
    import websocket, base64, json

# TOPIC = 'ws://CLUSTER_HOST:9090/ws/v2/consumer/persistent/public/default/test/sub'
TOPIC = 'wss://CLUSTER_HOST:9443/ws/v2/consumer/persistent/public/default/test/sub'
token = "YOUR_TOKEN"
header = ["Authorization:Bearer " + token]
ws = websocket.create_connection(TOPIC, header=header)
while True:
  msg = json.loads(ws.recv())
  if not msg: break
  print("Received: {} - payload: {}".format(msg, base64.b64decode(msg['payload'])))
  # Acknowledge successful processing
  ws.send(json.dumps({'messageId' : msg['messageId']}))

ws.close()
  3. Create a producer and use the producer to produce messages. 
    import websocket, base64, json

# TOPIC = 'ws://CLUSTER_HOST:9090/ws/v2/producer/persistent/public/default/test'
TOPIC = 'wss://CLUSTER_HOST:9443/ws/v2/producer/persistent/public/default/test'

token = "YOUR_TOKEN"

header = ["Authorization:Bearer " + token]

ws = websocket.create_connection(TOPIC, header=header)

# Send one message as JSON
ws.send(json.dumps({
'payload' : base64.b64encode('Hello World'),
'properties': {
  'key1' : 'VALUE1',
  'key2' : 'VALUE2'
},
'context' : 5
}))

response =  json.loads(ws.recv())
if response['result'] == 'ok':
  print('Message published successfully')
else:
  print('Failed to publish message:', response)
ws.close()