Configure your managed Spring Cloud Config Server in Azure Spring Apps (2023)

This article applies to: ✔️ Java ✔️ C#

This article applies to: ✔️ Standard consumption and dedicated (Preview) ✔️ Basic/Standard ❌ Enterprise

This article shows you how to configure a managed Spring Cloud Config Server in Azure Spring Apps service.

Spring Cloud Config Server provides server and client-side support for an externalized configuration in a distributed system. The Config Server instance provides a central place to manage external properties for applications across all environments. For more information, see the Spring Cloud Config documentation.

Prerequisites

• An Azure subscription. If you don't have an Azure subscription, create a free account before you begin.
• An already provisioned and running Azure Spring Apps service instance using the Basic or Standard plan. To set up and launch an Azure Spring Apps service, see Quickstart: Deploy your first application to Azure Spring Apps. Spring Cloud Config Server isn't applicable to the Enterprise plan.
• Git.

Restriction

There are some restrictions when you use Config Server with a Git back end. The following properties are automatically injected into your application environment to access Config Server and Service Discovery. If you also configure those properties from your Config Server files, you might experience conflicts and unexpected behavior.

eureka.client.service-url.defaultZoneeureka.client.tls.keystoreeureka.instance.preferIpAddresseureka.instance.instance-idserver.portspring.cloud.config.tls.keystorespring.config.importspring.application.namespring.jmx.enabledmanagement.endpoints.jmx.exposure.include

Create your Config Server files

Azure Spring Apps supports Azure DevOps Server, GitHub, GitLab, and Bitbucket for storing your Config Server files. When your repository is ready, you can create the configuration files and store them there.

Some configurable properties are available only for certain types. The following sections describe the properties for each repository type.

Public repository

When you use a public repository, your configurable properties are more limited than with a private repository.

The following table lists the configurable properties that you can use to set up a public Git repository.

Private repository with SSH authentication

The following table lists the configurable properties that you can use to set up a private Git repository with SSH.

Private repository with basic authentication

The following table lists the configurable properties that you can use to set up a private Git repository with basic authentication.

Other Git repositories

The following table lists the configurable properties you can use to set up Git repositories with a pattern.

The following table shows some examples of patterns for configuring your service with an optional extra repository. For more information, see the Extra repositories section and the Pattern Matching and Multiple Repositories section of the Spring documentation.

Attach your Config Server repository to Azure Spring Apps

Now that your configuration files are saved in a repository, use the following steps to connect Azure Spring Apps to the repository.

1. Sign in to the Azure portal.

2. Go to your Azure Spring Apps Overview page.

3. Select Config Server in the left navigation pane.

4. In the Default repository section, set URI to https://github.com/Azure-Samples/piggymetrics-config.

5. Select Validate.

6. When validation is complete, select Apply to save your changes.

Updating the configuration can take a few minutes. You should get a notification when the configuration is complete.

Enter repository information directly to the Azure portal

You can enter repository information for the default repository and, optionally, for extra repositories.

Default repository

Use the steps in this section to enter repository information for a public or private repository.

• Public repository: In the Default repository section, in the Uri box, paste the repository URI. Enter config for the Label setting. Ensure that the Authentication setting is Public, and then select Apply.

• Private repository: Azure Spring Apps supports basic password/token-based authentication and SSH.

  • Basic Authentication: In the Default repository section, in the Uri box, paste the repository URI, and then select the setting under Authentication to open the Edit Authentication pane. In the Authentication type drop-down list, select HTTP Basic, and then enter your username and password/token to grant access to Azure Spring Apps. Select OK, and then select Apply to finish setting up your Config Server instance.

  Note

  Many Git repository servers support the use of tokens rather than passwords for HTTP basic authentication. Some repositories allow tokens to persist indefinitely. However, some Git repository servers, including Azure DevOps Server, force tokens to expire in a few hours. Repositories that cause tokens to expire shouldn't use token-based authentication with Azure Spring Apps.

  GitHub has removed support for password authentication, so you need to use a personal access token instead of password authentication for GitHub. For more information, see Token authentication requirements for Git operations.

  • SSH: In the Default repository section, in the Uri box, paste the repository URI, and then select the setting under Authentication to open the Edit Authentication pane. In the Edit Authentication pane, in the Authentication type drop-down list, select SSH, and then enter your private key. Optionally, specify your host key and host key algorithm. Include your public key in your Config Server repository. Select OK, and then select Apply to finish setting up your Config Server instance.

Extra repositories

If you want to configure your service with an optional extra repository, specify the Uri and Authentication settings as you did for the default repository. Be sure to include a Name setting for your pattern, and then select Apply to attach it to your instance.

Enter repository information into a YAML file

If you've written a YAML file with your repository settings, you can import the file directly from your local machine to Azure Spring Apps. The following example shows a simple YAML file for a private repository with basic authentication.

spring: cloud: config: server: git: uri: https://github.com/azure-spring-cloud-samples/config-server-repository.git username: <username> password: <password/token>

Select the Import settings button, and then select the YAML file from your project directory. Select Import.

Your Notifications displays an async operation. Config Server should report success after 1-2 minutes. The information from your YAML file displays in the Azure portal. Select Apply to finish the import.

Use Azure Repos for Azure Spring Apps configuration

Azure Spring Apps can access Git repositories that are public, secured by SSH, or secured using HTTP basic authentication. HTTP basic authentication is the easiest of the options for creating and managing repositories with Azure Repos.

Get repo URL and credentials

Use the following steps to get your repo URL and credentials.

1. In the Azure Repos portal for your project, select the Clone button:

2. Copy the clone URL from the textbox. This URL is typically in the following form:

   https://<organization name>@dev.azure.com/<organization name>/<project name>/_git/<repository name>

   Remove everything after https:// and before dev.azure.com, including the @ symbol. The resulting URL should be in the following form:

   https://dev.azure.com/<organization name>/<project name>/_git/<repository name>

   Save this URL for use in the next section.

3. Select Generate Git Credentials to display a username and password, which should be saved for use in the following section.

Configure Azure Spring Apps to access the Git repository

1. Sign in to the Azure portal.

2. Go to your Azure Spring Apps Overview page.

3. Select the service to configure.

4. In the left pane of the service page under Settings, select the Config Server tab. Configure the repository you created, as follows:

   • Add the repository URI that you saved in the previous section.
   • Select the setting under Authentication to open the Edit Authentication pane.
   • For Authentication type, select HTTP Basic.
   • For Username, specify the user name that you saved in the previous section.
   • For Password, specify the password that you saved in the previous section.
   • Select OK, and then wait for the operation to complete.

Delete your configuration

Select Reset on the Config Server tab to erase your existing settings. Delete the config server settings if you want to connect your Config Server instance to another source, such as when you're moving from GitHub to Azure DevOps Server.

Config Server refresh

When properties are changed, services consuming those properties must be notified before changes can be made. The default solution for Spring Cloud Config Server is to manually trigger the refresh event, which may not be feasible if there are many app instances. For more information, see Centralized Configuration

Instead, you can automatically refresh values from Config Server by letting the config client poll for changes based on a refresh internal. Use the following steps to automatically refresh values from Config Server.

1. Register a scheduled task to refresh the context in a given interval, as shown in the following example.

   @ConditionalOnBean({RefreshEndpoint.class})@Configuration@AutoConfigureAfter({RefreshAutoConfiguration.class, RefreshEndpointAutoConfiguration.class})@EnableSchedulingpublic class ConfigClientAutoRefreshConfiguration implements SchedulingConfigurer { @Value("${spring.cloud.config.refresh-interval:60}") private long refreshInterval; @Value("${spring.cloud.config.auto-refresh:false}") private boolean autoRefresh; private RefreshEndpoint refreshEndpoint; public ConfigClientAutoRefreshConfiguration(RefreshEndpoint refreshEndpoint) { this.refreshEndpoint = refreshEndpoint; } @Override public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) { if (autoRefresh) { // set minimal refresh interval to 5 seconds refreshInterval = Math.max(refreshInterval, 5); scheduledTaskRegistrar.addFixedRateTask(() -> refreshEndpoint.refresh(), refreshInterval * 1000); } }}

2. Enable autorefresh and set the appropriate refresh interval in your application.yml file. In the following example, the client polls for configuration changes every 60 seconds, which is the minimum value you can set for a refresh interval.

   By default, autorefresh is set to false and the refresh-interval is set to 60 seconds.

   spring: cloud: config: auto-refresh: true refresh-interval: 60management: endpoints: web: exposure: include: - refresh

3. Add @RefreshScope in your code. In the following example, the variable connectTimeout is automatically refreshed every 60 seconds.

   @RestController@RefreshScopepublic class HelloController { @Value("${timeout:4000}") private String connectTimeout;}

For more information, see the config-client-polling sample.

Next steps

In this article, you learned how to enable and configure your Spring Cloud Config Server instance. To learn more about managing your application, see Scale an application in Azure Spring Apps.