Quickstart: Use Azure Cache for Redis with a Python app

Enable Microsoft Entra ID authentication on your cache

For an existing cache, first check to see if Microsoft Entra authentication is enabled. If it's not, complete the following steps to enable Microsoft Entra authentication. We recommend that you use Microsoft Entra ID for authentication in your applications.

1. In the Azure portal, select the Azure Cache for Redis instance where you'd like to use Microsoft Entra token-based authentication.

2. On the service menu, under Settings, select Authentication.

3. On the Authentication pane, check to see whether the Enable Microsoft Entra Authentication checkbox is selected. If it is, you can move on to the next section.

4. Otherwise, select the Enable Microsoft Entra Authentication checkbox. Then, enter the name of a valid user. Select Save. The user name that you enter is automatically assigned the Data Owner Access Policy.

   You also can enter a managed identity or a service principal to connect to your cache.

   

5. In a dialog box, you're asked if you want to update your configuration, and you're informed that making the update takes several minutes to finish. Select Yes.

   Important

   When the enable operation is finished, the nodes in your cache reboot to load the new configuration. We recommend that you complete this operation during your standard maintenance window or outside your peak business hours. The process can take up to 30 minutes.

For information about using Microsoft Entra ID with the Azure CLI, see the identity reference pages.

Install Microsoft Authentication Library

Microsoft Authentication Library (MSAL) gets security tokens from the Microsoft identity platform to authenticate users.

To install MSAL:

1. Install MSAL for Python.

2. Install the Python Azure identity client library. The library uses MSAL to provide token authentication support.

   Install this library by using pip:

pip install azure-identity

Create a Python script by using Microsoft Entra ID

1. Create a text file. Save the file as PythonApplication1.py.

2. In PythonApplication1.py, add and modify the following script.

   In the script:

   • Replace <Your Host Name> with the value from your Azure Cache for Redis instance. Your host name has the form <DNS name>.redis.cache.chinacloudapi.cn.
   • Replace <Your Username> with the value for your Microsoft Entra ID user.

   import redis
   from azure.identity import DefaultAzureCredential
   
   scope = "https://redis.azure.com/.default"
   host = "<Your Host Name>"
   port = 6380
   user_name = "<Your Username>"
   
   
   def hello_world():
       cred = DefaultAzureCredential()
       token = cred.get_token(scope)
       r = redis.Redis(host=host,
                       port=port,
                       ssl=True,    # ssl connection is required.
                       username=user_name,
                       password=token.token,
                       decode_responses=True)
       result = r.ping()
       print("Ping returned : " + str(result))
   
       result = r.set("Message", "Hello!, The cache is working with Python!")
       print("SET Message returned : " + str(result))
   
       result = r.get("Message")
       print("GET Message returned : " + result)
   
       result = r.client_list()
       print("CLIENT LIST returned : ")
       for c in result:
           print(f"id : {c['id']}, addr : {c['addr']}")
   
   if __name__ == '__main__':
       hello_world()
   

3. Before you run your Python code in a terminal, authorize the terminal to use Microsoft Entra ID:

   azd auth login

4. Run the PythonApplication1.py file by using Python. Verify that the output looks similar to this example:

   

Create a Python script by using reauthentication

A Microsoft Entra ID access token has a limited lifespan of approximately 75 minutes. To maintain a connection to your cache, you must refresh the token.

This example demonstrates how to refresh a token by using Python.

1. Create a text file. Save the file as PythonApplication2.py.

2. In PythonApplication2.py, add and modify the following script.

   In the script:

   • Replace <Your Host Name> with the value from your Azure Cache for Redis instance. Your host name has the form <DNS name>.redis.cache.chinacloudapi.cn.
   • Replace <Your Username> with the value for your Microsoft Entra ID user.

   import time
   import logging
   import redis
   from azure.identity import DefaultAzureCredential
   
   scope = "https://redis.azure.com/.default"
   host = "<Your Host Name>"
   port = 6380
   user_name = "<Your Username>"
   
   def re_authentication():
       _LOGGER = logging.getLogger(__name__)
       cred = DefaultAzureCredential()
       token = cred.get_token(scope)
       r = redis.Redis(host=host,
                       port=port,
                       ssl=True,   # ssl connection is required.
                       username=user_name,
                       password=token.token,
                       decode_responses=True)
       max_retry = 3
       for index in range(max_retry):
           try:
               if _need_refreshing(token):
                   _LOGGER.info("Refreshing token...")
                   tmp_token = cred.get_token(scope)
                   if tmp_token:
                       token = tmp_token
                   r.execute_command("AUTH", user_name, token.token)
               result = r.ping()
               print("Ping returned : " + str(result))
   
               result = r.set("Message", "Hello!, The cache is working with Python!")
               print("SET Message returned : " + str(result))
   
               result = r.get("Message")
               print("GET Message returned : " + result)
   
               result = r.client_list()
               print("CLIENT LIST returned : ")
               for c in result:
                   print(f"id : {c['id']}, addr : {c['addr']}")
               break
           except redis.ConnectionError:
               _LOGGER.info("Connection lost. Reconnecting.")
               token = cred.get_token(scope)
               r = redis.Redis(host=host,
                               port=port,
                               ssl=True,   # ssl connection is required.
                               username=user_name,
                               password=token.token,
                               decode_responses=True)
           except Exception:
               _LOGGER.info("Unknown failures.")
               break
   
   
   def _need_refreshing(token, refresh_offset=300):
       return not token or token.expires_on - time.time() < refresh_offset
   
   if __name__ == '__main__':
       re_authentication()
   

3. Run the PythonApplication2.py file by using Python. Verify that the output looks similar to this example:

   

   Unlike in the preceding example, if your token expires, the code in this example automatically refreshes the token.

Get the host name, ports, and access key

To connect to your Azure Cache for Redis server, the cache client needs the cache's host name, ports, and an access key. Some clients might refer to these items by using slightly different names. You can get the host name, ports, and keys in the Azure portal.

• To get an access key for your cache:

  1. In the Azure portal, go to your cache.
  2. On the service menu, under Settings, select Authentication.
  3. On the Authentication pane, select the Access keys tab.
  4. To copy the value for an access key, select the Copy icon in the key field.

  

• To get the host name and ports for your cache:

  1. In the Azure portal, go to your cache.
  2. On the service menu, select Overview.
  3. Under Essentials, for Host name, select the Copy icon to copy the host name value. The host name value has the form <DNS name>.redis.cache.chinacloudapi.cn.
  4. For Ports, select the Copy icon to copy the port values.

  

Read and write to the cache at the command line

To test your cache, run Python from the command line.

1. Initiate the Python interpreter in your command line by entering py.

2. Modify and then run the following code.

   In the code, replace <Your Host Name> and <Your Access Key> with the values from your Azure Cache for Redis instance. Your host name has the form <DNS name>.redis.cache.chinacloudapi.cn.

   >>> import redis
   >>> r = redis.Redis(host='<Your Host Name>',
           port=6380, db=0, password='<Your Access Key>', ssl=True)
   >>> r.set('foo', 'bar')
   True
   >>> r.get('foo')
   b'bar'
   

Create a Python script by using access keys

1. Create a new text file. Save the file as PythonApplication1.py.

2. In PythonApplication1.py, add and modify the following script.

   In the script:

   • Replace <Your Host Name> with the value from your Azure Cache for Redis instance. Your host name has the form <DNS name>.redis.cache.chinacloudapi.cn.
   • Replace <Your Access Key> with the value for your Microsoft Entra ID user.

   import redis
   
   myHostname = "<Your Host Name>"
   myPassword = "<Your Access Key>"
   
   r = redis.Redis(host=myHostname, port=6380,
                         password=myPassword, ssl=True)
   
   result = r.ping()
   print("Ping returned : " + str(result))
   
   result = r.set("Message", "Hello!, The cache is working with Python!")
   print("SET Message returned : " + str(result))
   
   result = r.get("Message")
   print("GET Message returned : " + result)
   
   result = r.client_list()
   print("CLIENT LIST returned : ")
   for c in result:
       print(f"id : {c['id']}, addr : {c['addr']}")
   

3. Run the PythonApplication1.py file by using Python. Verify that results like the following example appear as output: