enable-dynamic-configuration-go-console-app.md

title	Tutorial - Use dynamic configuration in a Go console app
titleSuffix	Azure App Configuration
description	In this quickstart, learn how to dynamically refresh Azure App Configuration data in a Go console application
ms.service	azure-app-configuration
services	azure-app-configuration
author	linglingye
ms.devlang	golang
ms.topic	quickstart
ms.custom	quickstart, mode-other, devx-track-go
ms.date	05/22/2025
ms.author	linglingye

Tutorial: Enable dynamic configuration refresh in a Go console app

In this quickstart, you'll enhance a basic Go console application to dynamically refresh configuration from Azure App Configuration. This allows your application to pick up configuration changes without requiring a restart.

Prerequisites

• Complete the Quickstart: Create a Go console app with Azure App Configuration as the starting point for this quickstart

Reload data from App Configuration

1. Open the file appconfig.go. Inside the loadAzureAppConfiguration function, update the options to enable refresh. Go provider will reload the entire configuration whenever it detects a change in any of the selected key-values (those starting with Config. and having no label). For more information about monitoring configuration changes, see Best practices for configuration refresh.

   options := &azureappconfiguration.Options{
       Selectors: []azureappconfiguration.Selector{
           {
               KeyFilter: "Config.*",
           },
       },
       TrimKeyPrefixes: []string{"Config."},
       RefreshOptions: azureappconfiguration.KeyValueRefreshOptions{
           Enabled:  true,
       },
   }

   [!TIP] You can set the Interval property of the RefreshOptions to specify the minimum time between configuration refreshes. In this example, you use the default value of 30 seconds. Adjust to a higher value if you need to reduce the number of requests made to your App Configuration store.

2. Open the file main.go and add the following code to your main function:

   // Existing code in main.go
   // ... ...
   fmt.Println("\nRaw JSON Configuration:")
   fmt.Println("------------------------")
   fmt.Println(string(jsonBytes))
   
   // Register refresh callback to update the configuration
   provider.OnRefreshSuccess(func() {
   	var updatedConfig Config
   	// Re-unmarshal the configuration
   	err := provider.Unmarshal(&updatedConfig, nil)
   	if err != nil {
   		log.Printf("Error unmarshalling updated configuration: %s", err)
   		return
   	}
   
   	fmt.Printf("Message: %s\n", updatedConfig.Message)
   })
   
   // Setup a channel to listen for termination signals
   done := make(chan os.Signal, 1)
   signal.Notify(done, syscall.SIGINT, syscall.SIGTERM)
   
   fmt.Println("\nWaiting for configuration changes...")
   fmt.Println("(Update values in Azure App Configuration to see refresh in action)")
   fmt.Println("Press Ctrl+C to exit")
   
   // Start a ticker to periodically trigger refresh
   ticker := time.NewTicker(30 * time.Second)
   defer ticker.Stop()
   
   // Keep the application running until terminated
   for {
       select {
       case <-ticker.C:
           // Trigger refresh in background
           go func() {
               ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
               defer cancel()
               
               if err := provider.Refresh(ctx); err != nil {
                   log.Printf("Error refreshing configuration: %s", err)
               }
           }()
       case <-done:
           fmt.Println("\nExiting...")
           return
       }
   }

Run the application

1. Run your application:

    go mod tidy
    go run .

2. Keep the application running.

3. Navigate to your App Configuration store and update the value of the Config.Message key.

   Key	Value	Content type
   Config.Message	Hello World - updated!	Leave empty

4. Observe your console application - within 30 seconds, it should detect the change and display the updated configuration.

Clean up resources

[!INCLUDE azure-app-configuration-cleanup]