Azure App Configuration client library for Python

Azure App Configuration is a managed service that helps developers centralize their application configurations simply and securely.

Modern programs, especially programs running in a cloud, generally have many components that are distributed in nature. Spreading configuration settings across these components can lead to hard-to-troubleshoot errors during an application deployment. Use App Configuration to securely store all the settings for your application in one place.

Use the client library for App Configuration to create and manage application configuration settings.

Source code | Package (Pypi) | API reference documentation | Product documentation

Getting started

Install the package

Install the Azure App Configuration client library for Python with pip:

pip install azure-appconfiguration

Prerequisites

• Python 2.7, or 3.5 or later is required to use this package.
• You need an Azure subscription, and a Configuration Store to use this package.

To create a Configuration Store, you can use the Azure Portal or Azure CLI.

After that, create the Configuration Store:

az appconfig create --name <config-store-name> --resource-group <resource-group-name> --location eastus

Authenticate the client

In order to interact with the App Configuration service, you'll need to create an instance of the AzureAppConfigurationClient class. To make this possible, you can either use the connection string of the Configuration Store or use an AAD token.

Use connection string

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.

Create client

Once you have the value of the connection string, you can create the AzureAppConfigurationClient:

from azure.appconfiguration import AzureAppConfigurationClient

connection_str = "<connection_string>"
client = AzureAppConfigurationClient.from_connection_string(connection_str)

Use AAD token

Here we demonstrate using DefaultAzureCredential to authenticate as a service principal. However, AzureAppConfigurationClient accepts any azure-identity credential. See the azure-identity documentation for more information about other credentials.

Create a service principal (optional)

This Azure CLI snippet shows how to create a new service principal. Before using it, replace "your-application-name" with the appropriate name for your service principal.

Create a service principal:

az ad sp create-for-rbac --name http://my-application --skip-assignment

Output:

{
    "appId": "generated app id",
    "displayName": "my-application",
    "name": "http://my-application",
    "password": "random password",
    "tenant": "tenant id"
}

Use the output to set AZURE_CLIENT_ID ("appId" above), AZURE_CLIENT_SECRET ("password" above) and AZURE_TENANT_ID ("tenant" above) environment variables. The following example shows a way to do this in Bash:

export AZURE_CLIENT_ID="generated app id"
export AZURE_CLIENT_SECRET="random password"
export AZURE_TENANT_ID="tenant id"

Assign one of the applicable App Configuration roles to the service principal.

Create a client

Once the AZURE_CLIENT_ID, AZURE_CLIENT_SECRET and AZURE_TENANT_ID environment variables are set, DefaultAzureCredential will be able to authenticate the AzureAppConfigurationClient.

Constructing the client also requires your configuration store's URL, which you can get from the Azure CLI or the Azure Portal. In the Azure Portal, the URL can be found listed as the service "Endpoint"

from azure.identity import DefaultAzureCredential
from azure.appconfiguration import AzureAppConfigurationClient

credential = DefaultAzureCredential()

client = AzureAppConfigurationClient(base_url="your_endpoint_url", credential=credential)

Key concepts

Configuration Setting

A Configuration Setting is the fundamental resource within a Configuration Store. In its simplest form it is a key and a value. However, there are additional properties such as the modifiable content type and tags fields that allow the value to be interpreted or associated in different ways.

The Label property of a Configuration Setting provides a way to separate Configuration Settings into different dimensions. These dimensions are user defined and can take any form. Some common examples of dimensions to use for a label include regions, semantic versions, or environments. Many applications have a required set of configuration keys that have varying values as the application exists across different dimensions. For example, MaxRequests may be 100 in "NorthAmerica", and 200 in "WestEurope". By creating a Configuration Setting named MaxRequests with a label of "NorthAmerica" and another, only with a different value, in the "WestEurope" label, an application can seamlessly retrieve Configuration Settings as it runs in these two dimensions.

Properties of a Configuration Setting:

key : str
label : str
content_type : str
value : str
last_modified : str
read_only : bool
tags : dict
etag : str

Examples

The following sections provide several code snippets covering some of the most common Configuration Service tasks, including:

• Create a Configuration Setting
• Get a Configuration Setting
• Delete a Configuration Setting
• List Configuration Settings
• Async APIs

Create a Configuration Setting

Create a Configuration Setting to be stored in the Configuration Store. There are two ways to store a Configuration Setting:

• add_configuration_setting creates a setting only if the setting does not already exist in the store.

config_setting = ConfigurationSetting(
    key="MyKey",
    label="MyLabel",
    value="my value",
    content_type="my content type",
    tags={"my tag": "my tag value"}
)
added_config_setting = client.add_configuration_setting(config_setting)

• set_configuration_setting creates a setting if it doesn't exist or overrides an existing setting.

config_setting = ConfigurationSetting(
    key="MyKey",
    label="MyLabel",
    value="my set value",
    content_type="my set content type",
    tags={"my set tag": "my set tag value"}
)
returned_config_setting = client.set_configuration_setting(config_setting)

Get a Configuration Setting

Get a previously stored Configuration Setting.

fetched_config_setting = client.get_configuration_setting(
    key="MyKey", label="MyLabel"
)

Delete a Configuration Setting

Delete an existing Configuration Setting.

deleted_config_setting = client.delete_configuration_setting(
    key="MyKey", label="MyLabel"
)

List Configuration Settings

List all configuration settings filtered with label_filter and/or key_filter.

filtered_listed = client.list_configuration_settings(
    label_filter="My*", key_filter="My*"
)
for item in filtered_listed:
    pass  # do something

Async APIs

Async client is supported for python 3.5+. To use the async client library, import the AzureAppConfigurationClient from package azure.appconfiguration.aio instead of azure.appconfiguration

from azure.appconfiguration.aio import AzureAppConfigurationClient

connection_str = "<connection_string>"
async_client = AzureAppConfigurationClient.from_connection_string(connection_str)

This async AzureAppConfigurationClient has the same method signatures as the sync ones except that they're async. For instance, to retrieve a Configuration Setting asynchronously, async_client can be used:

fetched_config_setting = await async_client.get_configuration_setting(
    key="MyKey", label="MyLabel"
)

To use list_configuration_settings, call it synchronously and iterate over the returned async iterator asynchronously

filtered_listed = async_client.list_configuration_settings(
    label_filter="My*", key_filter="My*"
)
async for item in filtered_listed:
    pass  # do something

Troubleshooting

Logging

This SDK uses Python standard logging library. You can configure logging print out debugging information to the stdout or anywhere you want.

import logging

logging.basicConfig(level=logging.DEBUG)

Http request and response details are printed to stdout with this logging config.

Next steps

More sample code

Several App Configuration client library samples are available to you in this GitHub repository. These include:

• Hello world / Async version
• Hello world with labels / Async version
• Make a configuration setting readonly / Async version
• Read revision history / Async version
• Get a setting if changed / Async version

For more details see the samples README.

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

1.1.1 (2020-10-05)

Features

• Improve error message if Connection string secret has incorrect padding #14140

1.1.0 (2020-09-08)

Features

• Added match condition support for set_read_only method #13276

1.0.1 (2020-08-10)

Fixes

• Doc & Sample fixes

1.0.0 (2020-01-06)

Features

• Add AAD auth support #8924

Breaking changes

• List_configuration_settings & list_revisions now take string key/label filter instead of keys/labels list #9066

1.0.0b6 (2019-12-03)

Features

• Add sync-token support #8418

Breaking changes

• Combine set_read_only & clear_read_only to be set_read_only(True/False) #8453

1.0.0b5 (2019-10-30)

Breaking changes

• etag and match_condition of delete_configuration_setting are now keyword argument only #8161

1.0.0b4 (2019-10-07)

• Add conditional operation support
• Add set_read_only and clear_read_only methods

1.0.0b3 (2019-09-09)

• New azure app configuration