Azure Function to read key values from Azure App Configuration

Almost 3 years ago, I wrote a blog post about How to get Key-values from Azure App Configuration within Logic Apps, and this is still valid today since we still don’t have an App Configuration Connector available out of the box. But I realize that I never blog about this resource in my blog.

There are many ways to store application configurations in Azure. At the top of the list is Key Vault which is ideal for storing secrets like passwords that should have limited access to the number of people that can see and modify these values.

However, not all configurations should need that tremendous restricted access. Neither all configurations are secrets. Of course, you can also use Key Vault to store non-secret information. But there are other options available like:

  • Using a SQL database with an app configuration table to store key values.
  • Depending on the services you are using, you can also use the default built-in App Configuration settings. For example, Azure Functions have it:

But you can also make use of the Azure App Configuration service.

Azure App Configuration stores configuration data as key-values. Key-values are a flexible and straightforward representation of developers’ application settings to make these configurations settings dynamic without redeploying your application if changes are required. However, they are not encrypted like the Key Vault, so it is a good solution to store non-sensitive data that you want to make dynamic in your application. 

Combining Azure App Configuration to store and manage your configurations and Azure Key Vault to store your secrets, we will obtain a powerful configuration management nearly for free.

App Configuration makes it easier to implement the following scenarios:

  • Centralize management and distribution of hierarchical configuration data for different environments and geographies
  • Dynamically change application settings without the need to redeploy or restart an application
  • Control feature availability in real-time

The only problem was that unlike Key Vault, which has an available connector to be used inside Logic Apps, App Configuration doesn’t have a connector available.

Get Azure App Configuration Value Function

This Function App is intended to close this gap and for you to be able to use it inside Logic Apps (or any other resource) and read App Configurations.

You can download the complete code for the function from GitHub. The link is below at the bottom of the blog post. Here is a small code snippet:

public static class GetAzureAppConfigurationValue
        public static async Task Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", Route = null)] HttpRequest req,
            ILogger log)
            string appKey = req.Query["appKey"];


                var builder = new ConfigurationBuilder();
                var build = builder.Build();

                string keyValue = build[appKey.ToString()];

                if (string.IsNullOrEmpty(keyValue))
                else return new OkObjectResult(keyValue);
            catch(Exception ex)
                var result = new ObjectResult(ex.Message);
                result.StatusCode = StatusCodes.Status500InternalServerError;
                return result;

This function requires that you pass as a query parameter the appKey parameter:

  • https://URL?appKey='<key-name>’

Where can I download it?

You can download the complete Azure Function source code here:

Hope you find this helpful! So, if you liked the content or found it helpful and want to help me write more content, you can buy (or help buy) my son a Star Wars Lego! 

Author: Sandro Pereira

Sandro Pereira lives in Portugal and works as a consultant at DevScope. In the past years, he has been working on implementing Integration scenarios both on-premises and cloud for various clients, each with different scenarios from a technical point of view, size, and criticality, using Microsoft Azure, Microsoft BizTalk Server and different technologies like AS2, EDI, RosettaNet, SAP, TIBCO etc. He is a regular blogger, international speaker, and technical reviewer of several BizTalk books all focused on Integration. He is also the author of the book “BizTalk Mapping Patterns & Best Practices”. He has been awarded MVP since 2011 for his contributions to the integration community.

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