Azure App Configuration Python Provider client library for Python

Azure App Configuration is a managed service that helps developers centralize their application configurations simply and securely. This provider adds additional functionality above the azure-sdk-for-python.

Using the provider enables loading sets of configurations from an Azure App Configuration store in a managed way.

Getting started

Get credentials

Use the Azure CLI snippet below to get the connection string from the Configuration Store.

az appconfig credential list --name <config-store-name>

Alternatively, get the connection string from the Azure Portal.

Creating a provider

You can create a client with a connection string:

from azure.appconfiguration.provider import load

config = load(connection_string="your-connection-string")

or with AAD:

from azure.appconfiguration.provider import load

config = load(endpoint="your-endpoint", credential=DefaultAzureCredential())

these providers will by default load all configurations with (No Label) from your configuration store into a dictionary of key/values.

Features

Currently the Azure App Configuration Provider enables:

• Connecting to an App Configuration Store using a connection string or Azure Active Directory.
• Selecting multiple sets of configurations using SettingSelector.
• Loading Feature Flags
• Dynamic Refresh
• Geo-Replication support
• Trim prefixes off key names.
• Resolving Key Vault References, requires AAD.
• Secret Resolver, resolve Key Vault References locally without connecting to Key Vault.
• Json Content Type

Future Features

List of features we are going to add to the Python Provider in the future.

• Configuration Placeholders

Examples

Selecting configurations

You can refine or expand the configurations loaded from your store by using SettingSelectors. Setting selectors provide a way to pass a key filter and label filter into the provider.

from azure.appconfiguration.provider import load, SettingSelector
from azure.identity import DefaultAzureCredential

selects = {SettingSelector(key_filter="*", label_filter="\0"), SettingSelector(key_filter="*", label_filter="dev")}
config = load(endpoint=endpoint, credential=DefaultAzureCredential(), selects=selects)

In this example all configuration with empty label and the dev label are loaded. Because the dev selector is listed last, any configurations from dev take priority over those with (No Label) when duplicates are found.

Dynamic Refresh

The provider can be configured to refresh configurations from the store on a set interval. This is done by providing a refresh_on to the provider, which is a list of key(s) that will be watched for changes, and when they do change a refresh can happen. refresh_interval is the period of time in seconds between refreshes. on_refresh_success is a callback that will be called only if a change is detected and no error happens. on_refresh_error is a callback that will be called when a refresh fails.

from azure.appconfiguration.provider import load, WatchKey
import os

connection_string = os.environ.get("APPCONFIGURATION_CONNECTION_STRING")

def my_callback_on_success():
    # Do something on success
    ...

def my_callback_on_fail(error):
    # Do something on fail
    ...

config = load(
    connection_string=connection_string,
    refresh_on=[WatchKey("Sentinel")],
    refresh_interval=60,
    on_refresh_success=my_callback_on_success,
    on_refresh_error=my_callback_on_fail,
    **kwargs,
)

In this example, the sentinel key will be checked for changes no sooner than every 60 seconds. In order to check for changes, the provider's refresh method needs to be called.

config.refresh()

Once the provider is refreshed, the configurations can be accessed as normal. And if any changes have been made it will be updated with the latest values. If the refresh_interval hasn't passed since the last refresh check, the provider will not check for changes.

For additional info check out Dynamic Refresh on MS Learn.

Trimming Keys

You can trim the prefix off of keys by providing a list of trimmed key prefixes to the provider. For example, if you have the key(s) like /application/message in your configuration store, you could trim /application/ from them.

from azure.appconfiguration.provider import load
from azure.identity import DefaultAzureCredential

trim_prefixes={"/application/"}
config = load(endpoint=endpoint, credential=DefaultAzureCredential(), trim_prefixes=trim_prefixes)
print(config["message"])

Resolving Key Vault References

Key Vault References can be resolved by providing credentials to your key vault to the provider using AzureAppConfigurationKeyVaultOptions.

With Credentials

You can provide AzureAppConfigurationKeyVaultOptions with a credential and all key vault references will be resolved with it. The provider will attempt to connect to any key vault referenced with the credential provided.

from azure.appconfiguration.provider import load, AzureAppConfigurationKeyVaultOptions
from azure.identity import DefaultAzureCredential

key_vault_options = AzureAppConfigurationKeyVaultOptions(credential=DefaultAzureCredential())
config = load(endpoint=endpoint, credential=DefaultAzureCredential(), key_vault_options=key_vault_options)

With Clients

You can provide AzureAppConfigurationKeyVaultOptions with a list of SecretClients.

from azure.appconfiguration.provider import load, AzureAppConfigurationKeyVaultOptions
from azure.identity import DefaultAzureCredential

key_vault_options = AzureAppConfigurationKeyVaultOptions(
    client_configs={key_vault_uri: {'credential': credential}})
config = load(endpoint=endpoint, credential=DefaultAzureCredential(), key_vault_options=key_vault_options)

Secret Resolver

If no Credentials or Clients are provided a secret resolver can be used. Secret resolver provides a way to return any value you want to a key vault reference.

from azure.appconfiguration.provider import load, AzureAppConfigurationKeyVaultOptions
from azure.identity import DefaultAzureCredential

def secret_resolver(uri):
    return "From Secret Resolver"

key_vault_options = AzureAppConfigurationKeyVaultOptions(
    secret_resolver=secret_resolver)
config = load(endpoint=endpoint, credential=DefaultAzureCredential(), key_vault_options=key_vault_options)

Geo Replication

The Azure App Configuration Provider library will automatically discover the provided configuration store's replicas and use the replicas if any issue arises. From more information see Geo-Replication.

Replica discovery is enabled by default. If you want to disable it, you can set replica_discovery_enabled to False.

from azure.appconfiguration.provider import load
from azure.identity import DefaultAzureCredential

config = load(endpoint=endpoint, credential=DefaultAzureCredential(), replica_discovery_enabled=False)

Loading Feature Flags

Feature Flags can be loaded from config stores using the provider. Feature flags are loaded as a dictionary of key/value pairs stored in the provider under the feature_management, then feature_flags.

config = load(endpoint=endpoint, credential=DefaultAzureCredential(), feature_flags_enabled=True)
alpha = config["feature_management"]["feature_flags"]["Alpha"]
print(alpha["enabled"])

By default all feature flags with no label are loaded when feature_flags_enabled is set to True. . If you want to load feature flags with a specific label you can use SettingSelector to filter the feature flags.

from azure.appconfiguration.provider import load, SettingSelector

config = load(endpoint=endpoint, credential=DefaultAzureCredential(), feature_flags_enabled=True, feature_flag_selectors=[SettingSelector(key_filter="*", label_filter="dev")])
alpha = config["feature_management"]["feature_flags"]["Alpha"]
print(alpha["enabled"])

To enable refresh for feature flags you need to enable refresh. This will allow the provider to refresh feature flags the same way it refreshes configurations. Unlike configurations, all loaded feature flags are monitored for changes and will cause a refresh. Refresh of configuration settings and feature flags are independent of each other. Both are trigged by the refresh method, but a feature flag changing will not cause a refresh of configurations and vice versa. Also, if refresh for configuration settings is not enabled, feature flags can still be enabled for refresh.

config = load(endpoint=endpoint, credential=DefaultAzureCredential(), feature_flags_enabled=True, feature_flag_refresh_enabled=True)

...

config.refresh()

Key concepts

Troubleshooting

Next steps

Check out our Django and Flask examples to see how to use the provider in a web application.

Django

Flask

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information, see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

Release History

2.0.0b1 (2024-09-11)

Features Added

• Added support for feature flag telemetry.

1.3.0 (2024-09-09)

Features Added

• Added support for auto failover between replicas.
• Added support for auto discovery of replicas.

1.2.0 (2024-05-24)

Features Added

• Enable loading of feature flags with feature_flag_enabled
• Select Feature Flags to load with feature_flag_selectors
• Enable/Disable Feature Flag Refresh with feature_flag_refresh_enabled

Bugs Fixed

• Fixes issue where loading configurations were slower due to returning a copy of the configurations.

1.1.0 (2024-01-29)

Features Added

• New API for Azure App Configuration Provider, refresh, which can be used to refresh the configuration from the Azure App Configuration service. refresh by default can check every 30 seconds for changes to specified sentinel keys. If a change is detected then all configurations are reloaded. Sentinel keys can be set by passing a list of SentinelKey's to refresh_on.
• Added new options on_refresh_success and on_refresh_failure callbacks to the load method. These callbacks are called when the refresh method successfully refreshes the configuration or fails to refresh the configuration.

Bugs Fixed

• Verifies that the refresh_interval is at least 1 second.

1.1.0b3 (2023-12-19)

Features Added

• Added on_refresh_success callback to load method. This callback is called when the refresh method successfully refreshes the configuration.
• Added minimum up time. This is the minimum amount of time the provider will try to be up before throwing an error. This is to prevent quick restart loops.

Bugs Fixed

• Fixes issue where the refresh timer only reset after a change was found.

Other Changes

• Renamed the type SentinelKey to be WatchKey.

1.1.0b2 (2023-09-29)

Features Added

• Added support for keyvault_credential, keyvault_client_configs, and secret_resolver as kwargs instead of using AzureAppConfigurationKeyVaultOptions.

Bugs Fixed

• Fixes issue where user_agent was required to be set.
• Fixes issue where correlation context info is wrong on refresh.

1.1.0b1 (2023-09-13)

Features Added

• New API for Azure App Configuration Provider, refresh, which can be used to refresh the configuration from the Azure App Configuration service. refresh by default can check every 30 seconds for changes to specified sentinel keys. If a change is detected then all configurations are reloaded. Sentinel keys can be set by passing a list of SentinelKey's to refresh_on.
• Added support for customer provided user agent prefix.

Other Changes

• Updated to use AZURE_APP_CONFIGURATION_TRACING_DISABLED environment variable to disable tracing.
• Changed the maximum number of retries to 2 from the default of 3 retries.
• Changed the maximum back off time between retries to 1 minute from the default of 2 minutes.
• Bumped minimum dependency on azure-core to >=1.25.0

1.0.0 (2023-03-09)

Breaking Changes

• Renamed load_provider to load
• Added AzureAppConfigurationKeyVaultOptions to take in a client_configs a Mapping of endpoints to client kwargs instead of taking in the whole client.
• Removed AzureAppConfigurationKeyVaultOptions secret_clients, client_configs should be used instead.
• Made key_filter and label_filter kwargs for Setting Selector
• Renamed trimmed_key_prefixes to trim_prefixes

Other Changes

• Made EMPTY_LABEL a constant. i.e. "\0"

1.0.0b2 (2023-02-15)

Features Added

• Added Async Support
• Added missing methods for Mapping API
• Made load method properties unordered.

Breaking Changes

• Changes how load works. Moves if from AzureAppConfigurationProvider.load to load_provider.
• Removed custom Key Vault Error
• Removed unneeded repr and copy methods.
• All Feature Flags are added to there own key and have there prefix removed

Bugs Fixed

• Fixed Issue where Key Vault Clients couldn't be set in some situations

Other Changes

• Updated method docs
• Fixed load doc that used selector instead of selects.
• Fixed CLI link in Readme.

1.0.0b1 (2022-10-13)

New Azure App Configuration Provider

Provides additional support above the Azure App Configuration SDK. Enables:

• Connecting to an Azure App Configuration store
• Selecting multiple keys using Setting Selector
• Resolve Key Vault References when supplied AzureAppConfigurationKeyVaultOptions

The Azure App Configuration Provider once loaded returns a dictionary of key/value pairs to use in configuration.

endpoint = "https://<your-store>.azconfig.io"
default_credential = DefaultAzureCredential()
config = AzureAppConfigurationProvider.load(
    endpoint=endpoint, credential=default_credential)
print(config["message"])