CODEWITHSUNDEEP
python-3.xfeature-flags
Malcode
Malcode

Reputation: 301

Python : Implementing Feature Flags based on Environment (dev, prod)

I would like the features to be based on the environment. For example a feature is being worked or tested so I could have it on in DEV , but it's not ready for the public, so it's turned off in PROD.

Do I need to implement a custom strategy or can I use one of the existing strategies in a creative way?

If there any concise example that would be most helpful.

Upvotes: 0

Views: 1185

Answers (1)

Sandrine Adap
Sandrine Adap

Reputation: 9

The easiest way I’ve found to implement feature flags at the environment level is to use a third-party hosted management system. Many feature flag services allow you to control which environment a flag will be enabled in. In the example below, I used DevCycle’s Python SDK, referencing feature flags and environments I had created in the DevCycle dashboard.

First, I installed the SDK from the command line:

$ pip install devcycle-python-server-sdk

Then I initialized the SDK it with the SDK key that corresponded to my desired environment. In this case, I used the key for my Dev environment. DevCycle provides SDK keys for each environment you set up.

from __future__ import print_function
from devcycle_python_sdk import Configuration, DVCClient
from devcycle_python_sdk.rest import ApiException
configuration = Configuration()

# Set up authorization
configuration.api_key['Authorization'] = 'SDK_KEY_FOR_DEV_ENV'

# Create an instance of the API class
dvc = DVCClient(configuration)

# Create user object. All functions require user data to be an instance of the UserData class
user = UserData(
  user_id='test'
)

key = 'enable-feature-flag' # feature flag key created in the DevCycle Dashboard

try:
  # Fetch variable values using the identifier key, with a default value and user object
  # The default value can be of type string, boolean, number, or JSON
  flag = dvc.variable(user, key, False)

  # Use received value of feature flag. 
  if flag.value:
    # Put feature code here, or launch feature from here
  else:
    # Put existing functionality here

except ApiException as e:
  print("Exception when calling DVCClient->variable: %s" %e)

By passing in the SDK key for my Dev environment, 'SDK_KEY_FOR_DEV_ENV', it gives my program access to only the features enabled in Dev. You can choose which environment(s) a feature is enabled in directly from the DevCycle dashboard. So if 'enable-feature-flag' was set to true for your Dev environment, you would see your feature. Likewise, you could set 'enable-feature-flag' to false in your Prod environment, and replace 'SDK_KEY_FOR_DEV_ENV' with the key for your Prod environment. This would disable the new functionality from Prod.

Full disclosure: My name is Sandrine and I am a Developer Advocate for DevCycle. I hope this answer helps you get started on environment-specific feature flags.

Upvotes: 0

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