Implementing External Configuration Store Pattern using Azure App Configuration

The External Configuration Store Pattern is a design pattern in software development that aims to keep the configuration of an application in an external store rather than hardcoding it directly into the application. Instead of defining configuration settings such as database connection strings, API endpoints, or other customizations directly in the code, they are stored in an external store like a database, a configuration file store, or a cloud-based service.

Here are the key concepts and principles of the External Configuration Store Pattern:

• External Store: The application’s configuration is kept in an external store, which is retrieved by the application. This can be a database, a configuration file, a key-value store, or a cloud-based service such as Azure App Configuration.
• Decoupling Configuration from Code: By using an external store for configurations, the configuration is decoupled from application development. This allows for updating configuration settings without making changes to the application code.
• Dynamic Updating: Applications can dynamically retrieve configurations from the external store, allowing changes to configuration settings to be applied without restarting the application. This enables flexible and responsive management of configuration changes.
• Support for Different Environments: The External Configuration Store Pattern supports the management of configurations for different environments such as development, testing, and production by providing different sets of configurations for each environment.
• Versioning and Tracking: The external store can offer version control and tracking features for configuration settings, allowing changes to be tracked, compared, and restored if needed.
• Security and Access Control: The external store can provide security and access control features to manage access to configuration settings and protect sensitive information.

By keeping configuration settings in an external store, the External Configuration Store Pattern offers a flexible and scalable solution for managing application configurations. It enables easier management, updating, and handling of configuration settings and supports a clean separation of configurations and application code.

Azure App Configuration Service

Azure App Configuration is a service that supports this pattern by providing a central and scalable platform for storing and managing application configurations.

Here’s how the External Configuration Store Pattern relates to Azure App Configuration:

• Centralized Configuration Storage: Azure App Configuration offers a centralized source for storing configuration data. Applications can access this external configuration source to retrieve their configurations instead of storing them locally.
• Dynamic Configuration Updates: Azure App Configuration enables dynamic updates of configurations without requiring an application restart. This means that changes to configurations can be immediately adopted by all instances of the application that access Azure App Configuration.
• Support for Different Environments: With Azure App Configuration, different environments such as development, testing, and production can be supported by providing different sets of configurations for each environment. This allows for a clean separation of configurations across different environments.
• Configuration Versioning: Azure App Configuration offers version control features for configuration data, enabling changes to be tracked, compared, and restored if necessary. This allows for better management and tracking of configuration changes over time.
• Integration into Applications: Applications can easily access and use configurations via the Azure App Configuration client libraries. This integration facilitates the use of the External Configuration Store Pattern in applications without requiring additional implementation effort.

Overall, Azure App Configuration provides a powerful platform for implementing the External Configuration Store Pattern by offering a centralized and flexible solution for managing application configurations. Developers can benefit from the advantages of this design pattern by using Azure App Configuration to make their applications more efficient and flexible.

In the second part you can see a coding example using an ASP.NET Core Api.