VMware Cloud Director: Push Notifications in Tenant Context

In VMware Cloud Director 10.1 (VCD) the organization users can subscribe to event and task push notifications which might be useful if the tenant needs to keep track of the activity in the cloud, connect CMDB or any other custom solution and does not want to permanently poll audit log via API.

Access to notifications was in the past only in the realm of service providers who needed to deploy RabbitMQ and connect their Cloud Director cells to it. They can still do so and in fact have to, if they need blocking taks or use VCD API extension (for example Container Service Extension, App Launch Pad or vRealize Operations Tenant App).

The new functionality is enabled by internal Artemis ActiveMQ bus that runs on every VCD cell. The MQTT client connects to the public https endpoint and uses WebSocket connnection to the bus. Authentication is provided via the JWT authentication token. The official documentation provides some detail here, but not enough to actually set this up.

Therefore I want to demonstrate here with very simple Python script how to set up connection and start utilizing this feature.

The Python 3 script leverages the Pyvcloud module (22.0 or newer is required) and Paho MQTT Python Client. Both can be installed simply with pip.

pip install pyvcloud paho-mqtt

In the example org admin credentials are used, which allows to subscription to all organization messages via publish/<org UUID>/* subscription string. It can also be used by system administrator while changing the subscription string to publish/*/*.

#!/usr/bin/python3

import paho.mqtt.client as mqtt
import json
import datetime
import pyvcloud.vcd.client
import pyvcloud.vcd.vdc

vcdHost = 'vcloud.fojta.com'
vcdPort = 443
path = "/messaging/mqtt"
logFile = 'vcd_log.log'

#org admin credentials
user = 'acmeadmin'
password = 'VMware1!'
org = 'acme'

credentials = pyvcloud.vcd.client.BasicLoginCredentials(user, org, password)
vcdClient = pyvcloud.vcd.client.Client(vcdHost+":"+str(vcdPort),None,True,logFile)
vcdClient.set_credentials(credentials)
accessToken = vcdClient.get_access_token()
headers = {"Authorization": "Bearer "+ accessToken}

if max(vcdClient.get_supported_versions_list()) < "34.0":
    exit('VMware Cloud Director 10.1 or newer is required')

org = vcdClient.get_org_list()
orgId = (org[0].attrib).get('id').split('org:',1)[1]

def on_message(client, userdata, message):
    event = message.payload.decode('utf-8')
    event = event.replace('\\','')
    eventPayload = event.split('payload":"',1)[1]
    eventPayload = eventPayload[:-2]
    event_json = json.loads(eventPayload)
    print(datetime.datetime.now())
    print (event_json)

# Enable for logging
# def on_log(client, userdata, level, buf):
#     print("log: ",buf)

client = mqtt.Client(client_id = "PythonMQTT",transport = "websockets")
client.ws_set_options(path = path, headers = headers)
client.tls_set_context(context=None)
# client.tls_insecure_set(True)
client.on_message=on_message
# client.on_log=on_log  #enable for logging
client.connect(host = vcdHost, port = vcdPort , keepalive = 60)
print('Connected')
client.subscribe("publish/"+orgId+"/*")
client.loop_forever()

Notice that the client needs to connect to the /messaging/mqtt path on the VCD endpoint and must provide valid JWT authentication token in the header. That rules some MQTT WebSocket clients that do not support custom headers (JavaScript).

The actual event is in JSON format with nested payload JSON providing the details. The code example prints the time when the event was received and just the nested payload JSON. The script runs forever until interrupted with Ctrl+C.

Note: The actual RabbitMQ extensibility configuration in VCD and the Non-blocking AMQP Notifications setting in the UI have no impact on this functionality and can be disabled if not used by the service provider.

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