Skip to main content

Data Access through Subscription

To register subscription, a user must request for consent from the provider, obtain a token from IUDX Auth server and then access the Subscription API.

Obtaining token to Subscribe a resource

A consumer can obtain a token using the Create Token APIs with the following request body. Make sure that the appropriate resource (or) resource_group id is used to obtain a token.

Example For a subscription at a resource level

{
  "itemId": "datakaveri.org/04a15c9960ffda227e9546f3f46e629e1fe4132b/rs.iudx.org.in/pune-env-aqm/184ba502-22a8-ad15-a8f1-c966cd3aa7a7",
  "itemType": "resource",
  "role": "consumer"
}

Example For a subscription at a resource group level

{
  "itemId": "datakaveri.org/04a15c9960ffda227e9546f3f46e629e1fe4132b/rs.iudx.org.in/pune-env-aqm",
  "itemType": "resource_group",
  "role": "consumer"
}

It is to be noted that unless an explicit policy for subscription is specified by the Provider in the IUDX Authorisation Server a consumer will not obtain any access token.

Creating a new subscription

A consumer can use the Subscription APIs to register a new subscription. On registration, information about the streaming server which includes URL, port, vHost along with subscription-id, username and apiKey will be shared. Using the above information a consumer can connect to the streaming server to get the requested data as a stream.

import pika
import urllib.parse

username = '15c7506f-c800-48d6-adeb-0542b03947c6' #change this to your user name
password = 'u-Tdy3g_ToeQikHfnovjMA' #change this to your password.
host = 'localhost'
port = 49153
vhost = 'IUDX'
queue_name = '15c7506f-c800-48d6-adeb-0542b03947c6/itms-application' #change this to your queue-name (id)
encoded_username = urllib.parse.quote_plus(username)

connection = pika.BlockingConnection(
    pika.URLParameters(f'amqp://{encoded_username}:{password}@{host}:{port}/{vhost}'))

channel = connection.channel()

print(' [*] Waiting for data. To exit press CTRL+C')


def callback(ch, method, properties, body):
    print(" [x] %r" % body)

channel.basic_consume(
    queue=queue_name, on_message_callback=callback, auto_ack=True)

channel.start_consuming()

Obtaining token to refresh an existing Subscription of a resource

A consumer can obtain a token to refresh an existing subscription using the same approach as mention in Obtaining token to Subscribe a resource.

Refreshing a subscription

In order to keep the subscription open and live, consumer should call the Refresh Subscription API every 12 hours until policy expiry. On failure to do so, the access to subscription will be revoked. A consumer should then use the Append Subscription API to restart the subscription.

Adding a new resource to an existing subscription

A consumer can use the Append Subscription API to add new resources to an existing subscription. This will make the consumer to receive more than one resource in the same stream.

Note: A resource can be differentiated using the id available in the data packet.

Deleting a subscription

A consumer can use the Delete Subscription API to delete a subscription. This will delete the subscription queue and all existing resources streamed through the queue will be inaccessible.

Reset Streaming User Password

A consumer can reset the password given to them by the streaming server using the Reset Streaming Password API. This change will reset all active connections and a consumer should restart their client applications accordingly.