Tutorial: Connect to a managed Admin for Spring in Azure Container Apps

The Admin for Spring managed component offers an administrative interface for Spring Boot web applications that expose actuator endpoints. As a managed component in Azure Container Apps, you can easily bind your container app to Admin for Spring for seamless integration and management.

This tutorial shows you how to create an Admin for Spring Java component and bind it to your container app so that you can monitor and manage your Spring applications with ease.

In this tutorial, you learn how to:

• Create an Admin for Spring Java component.
• Bind your container app to an Admin for Spring Java component.

If you want to integrate Admin for Spring with Eureka Server for Spring, see Integrate Admin for Spring with Eureka Server for Spring in Container Apps instead.

Important

This tutorial uses services that can affect your Azure bill. If you decide to follow along, make sure you delete the resources featured in this article to avoid unexpected billing.

Prerequisites

• An Azure account with an active subscription. If you don't already have one, you can can create one for free.
• Azure CLI.

Considerations

When you run the Admin for Spring component in Container Apps, be aware of the following details:

Item	Explanation
Scope	Components run in the same environment as the connected container app.
Scaling	Component can’t scale. The scaling properties minReplicas and maxReplicas are both set to 1.
Resources	The container resource allocation for components is fixed. The number of the CPU cores is 0.5, and the memory size is 1 Gi.
Pricing	Component billing falls under consumption-based pricing. Resources consumed by managed components are billed at the active/idle rates. You can delete components that are no longer in use to stop billing.
Binding	Container apps connect to a component via a binding. The bindings inject configurations into container app environment variables. After a binding is established, the container app can read the configuration values from environment variables and connect to the component.

Setup

Before you begin to work with the Admin for Spring component, you first need to create the required resources.

Azure CLI

The following commands help you create your resource group and container app environment.

1. Create variables to support your application configuration. These values are provided for you for the purposes of this lesson.

   export LOCATION=eastus
   export RESOURCE_GROUP=my-resource-group
   export ENVIRONMENT=my-environment
   export JAVA_COMPONENT_NAME=admin
   export APP_NAME=sample-admin-client
   export IMAGE="mcr.microsoft.com/javacomponents/samples/sample-admin-for-spring-client:latest"
   

   Variable	Description
   LOCATION	The Azure region location where you create your container app and Java component.
   ENVIRONMENT	The container app environment name for your demo application.
   RESOURCE_GROUP	The Azure resource group name for your demo application.
   JAVA_COMPONENT_NAME	The name of the Java component created for your container app. In this case, you create an Admin for Spring Java component.
   IMAGE	The container image used in your container app.

2. Sign in to Azure with the Azure CLI.

   az login
   

3. Create a resource group.

   az group create \
       --name $RESOURCE_GROUP \
       --location $LOCATION \
       --query "properties.provisioningState"
   

   When you use the --query parameter, the response filters down to a simple success or failure message.

4. Create your container app environment.

   az containerapp env create \
       --name $ENVIRONMENT \
       --resource-group $RESOURCE_GROUP \
       --location $LOCATION
   

Azure portal

To create each of the resources necessary to create a container app, follow these steps:

1. Search for Container Apps in the Azure portal and select Create.

2. On the Basics tab, enter the following values:

   Property	Value
   Subscription	Select your Azure subscription.
   Resource group	Select Create new to create a new resource group named my-resource-group.
   Container app name	Enter sample-admin-client.
   Deployment source	Select Container image.
   Region	Select the region nearest you.
   Container app environment	Select Create new to create a new environment.

3. On the Create Container Apps environment window, enter the following values:

   Property	Value
   Environment name	Enter my-environment.
   Zone redundancy	Select Disabled.

4. Select Create, and then select the Container tab.

5. On the Container tab, enter the following values:

   Property	Value
   Name	Enter sample-admin-client.
   Image source	Select Docker Hub or other registries.
   Image type	Select Public.
   Registry sign-in server	Enter mcr.microsoft.com.
   Image and tag	Enter javacomponents/samples/sample-admin-for-spring-client:latest.

6. Select the Ingress tab.

7. On the Ingress tab, enter the following values and leave the rest of the form filled in with the default values.

   Property	Value
   Ingress	Select Enabled.
   Ingress traffic	Select Accept traffic from anywhere.
   Ingress type	Select HTTP.
   Target port	Enter 8080.

8. Select Review + create.

9. After the validation checks pass, select Create to create your container app.

Use the component

Azure CLI

Now that you have an existing environment, you can create your container app and bind it to a Java component instance of an Admin for Spring component.

1. Create the Admin for Spring Java component.

   az containerapp env java-component admin-for-spring create \
       --environment $ENVIRONMENT \
       --resource-group $RESOURCE_GROUP \
       --name $JAVA_COMPONENT_NAME \
       --min-replicas 1 \
       --max-replicas 1
   

2. Update the Admin for Spring Java component.

   az containerapp env java-component admin-for-spring update \
       --environment $ENVIRONMENT \
       --resource-group $RESOURCE_GROUP \
       --name $JAVA_COMPONENT_NAME \
       --min-replicas 2 \
       --max-replicas 2
   

Azure portal

Now that you have an existing environment and admin client container app, you can create a Java component instance of Admin for Spring.

1. Go to your container app's environment in the portal.

2. On the service menu, under Services, select Services.

3. Select the Configure dropdown, then select Java component.

4. On the Configure Java component pane, enter the following values:

   Property	Value
   Java component type	Select Admin for Spring.
   Java component name	Enter admin.

5. Select Next.

6. On the Review tab, select Configure.

Bind your container app to the Admin for Spring Java component

Azure CLI

1. Create the container app and bind it to the Admin for Spring component.

   az containerapp create \
       --name $APP_NAME \
       --resource-group $RESOURCE_GROUP \
       --environment $ENVIRONMENT \
       --image $IMAGE \
       --min-replicas 1 \
       --max-replicas 1 \
       --ingress external \
       --target-port 8080 \
       --bind $JAVA_COMPONENT_NAME
   

Azure portal

1. Go to your Container App environment in the portal.

2. On the service menu, under Services, select Services.

3. From the list, select admin.

4. Under Bindings, select the App name dropdown, then select sample-admin-client.

5. Select the Review tab.

6. Select Configure.

7. Return to your container app in the portal. Copy the URL of your app to a text editor so that you can use it in an upcoming step.

The bind operation binds the container app to the Admin for Spring Java component. The container app can now read the configuration values from environment variables, primarily the SPRING_BOOT_ADMIN_CLIENT_URL property, and connect to the Admin for Spring component.

The binding also injects the following property:

"SPRING_BOOT_ADMIN_CLIENT_INSTANCE_PREFER-IP": "true",

This property indicates that the Admin for Spring component client should prefer the IP address of the container app instance when you connect to the Admin for Spring server.

Optional: Unbind your container app from the Admin for Spring Java component

Azure CLI

To remove a binding from a container app, use the --unbind option.

az containerapp update \
    --name $APP_NAME \
    --unbind $JAVA_COMPONENT_NAME \
    --resource-group $RESOURCE_GROUP

Azure portal

1. Go to your container app environment in the portal.

2. On the service menu, under Services, select Services.

3. From the list, select admin.

4. Under Bindings, find the line for sample-admin-client, select it, and then select Delete.

5. Select Next.

6. Select the Review tab.

7. Select Configure.

View the dashboard

Important

To view the dashboard, you need to have at least the Microsoft.App/managedEnvironments/write role assigned to your account on the managed environment resource. You can explicitly assign the Owner or Contributor role on the resource. You can also follow the steps to create a custom role definition and assign it to your account.

1. Create the custom role definition.

   az role definition create --role-definition '{
       "Name": "<ROLE_NAME>",
       "IsCustom": true,
       "Description": "Can access managed Java Component dashboards in managed environments",
       "Actions": [
           "Microsoft.App/managedEnvironments/write"
       ],
       "AssignableScopes": ["/subscriptions/<SUBSCRIPTION_ID>"]
   }'
   

   Make sure to replace the placeholders in between the <> brackets with your values.

2. Assign the custom role to your account on the managed environment resource.

   Get the resource ID of the managed environment:

   export ENVIRONMENT_ID=$(az containerapp env show \
       --name $ENVIRONMENT --resource-group $RESOURCE_GROUP \ 
       --query id \
       --output tsv)
   

3. Assign the role to your account.

   Before you run this command, replace the placeholder - as indicated by the <> brackets - with your user or service principal ID or role name.

   az role assignment create \
       --assignee <USER_OR_SERVICE_PRINCIPAL_ID> \
       --role "<ROLE_NAME>" \
       --scope $ENVIRONMENT_ID
   

   Note

   The <USER_OR_SERVICE_PRINCIPAL_ID> value should be the identity that you use to access the Azure portal. The <ROLE_NAME> value is the name that you assigned in step 1.

4. Get the URL of the Admin for Spring dashboard.

   az containerapp env java-component admin-for-spring show \
       --environment $ENVIRONMENT \
       --resource-group $RESOURCE_GROUP \
       --name $JAVA_COMPONENT_NAME \
       --query properties.ingress.fqdn \
       --output tsv
   

   This command returns the URL that you can use to access the Admin for Spring dashboard. With the dashboard, you can also see your container app, as shown in the following screenshot.

   

Clean up resources

The resources created in this tutorial have an effect on your Azure bill. If you aren't going to use these services long term, run the following command to remove everything you created in this tutorial.

az group delete --resource-group $RESOURCE_GROUP

Dependency

When you use the admin component in your own container app, you need to add the following dependency in your pom.xml file. Replace the version number with the latest version available on the Maven Repository.

<dependency>
    <groupId>de.codecentric</groupId>
    <version>3.3.2</version>
    <artifactId>spring-boot-admin-starter-client</artifactId>
</dependency>

Configurable properties

Starting with Spring Boot 2, endpoints other than health and info aren't exposed by default. You can expose them by adding the following configuration in your application.properties file.

management.endpoints.web.exposure.include=*
management.endpoint.health.show-details=always

Allowed configuration list for your Admin for Spring

The following list details the admin component properties you can configure for your app. For more information, see Spring Boot Admin.

Property name	Description	Default value
spring.boot.admin.server.enabled	Enables the Spring Boot Admin Server.	true
spring.boot.admin.context-path	The path prefix where the Admin Server's statics assets and API are served. Relative to the Dispatcher-Servlet.
spring.boot.admin.monitor.status-interval	Time interval in milliseconds to check the status of instances.	10,000ms
spring.boot.admin.monitor.status-lifetime	Lifetime of status in milliseconds. The status isn't updated as long as the last status isn't expired.	10,000 ms
spring.boot.admin.monitor.info-interval	Time interval in milliseconds to check the info of instances.	1m
spring.boot.admin.monitor.info-lifetime	Lifetime of info in minutes. The info isn't updated as long as the last info isn't expired.	1m
spring.boot.admin.monitor.default-timeout	Default timeout when making requests. Individual values for specific endpoints can be overridden using spring.boot.admin.monitor.timeout.*.	10,000
spring.boot.admin.monitor.timeout.*	Key-value pairs with the timeout per endpointId.	Defaults to default-timeout value.
spring.boot.admin.monitor.default-retries	Default number of retries for failed requests. Requests that modify data (PUT, POST, PATCH, DELETE) are never retried. Individual values for specific endpoints can be overridden using spring.boot.admin.monitor.retries.*.	0
spring.boot.admin.monitor.retries.*	Key-value pairs with the number of retries per endpointId. Requests that modify data (PUT, POST, PATCH, DELETE) are never retried.	Defaults to default-retries value.
spring.boot.admin.metadata-keys-to-sanitize	Metadata values for the keys matching these regex patterns used to sanitize in all JSON output. Starting from Spring Boot 3, all actuator values are masked by default. For more information about how to configure the unsanitization process, see Sanitize Sensitive Values.	".*password$", ".*secret$", ".*key$", ".*token$", ".*credentials.*", ".*vcap_services$"
spring.boot.admin.probed-endpoints	For Spring Boot 1.x client applications, Spring Boot Admin probes for the specified endpoints using an OPTIONS request. If the path differs from the ID, you can specify this value as id:path - for example, health:ping.	"health", "env", "metrics", "httptrace:trace", "threaddump:dump", "jolokia", "info", "logfile", "refresh", "flyway", "liquibase", "heapdump", "loggers", "auditevents"
spring.boot.admin.instance-proxy.ignored-headers	Headers not to forwarded when making requests to clients.	"Cookie", "Set-Cookie", "Authorization"
spring.boot.admin.ui.title	The displayed page title.	"Spring Boot Admin"
spring.boot.admin.ui.poll-timer.cache	Polling duration in milliseconds to fetch new cache data.	2500
spring.boot.admin.ui.poll-timer.datasource	Polling duration in milliseconds to fetch new data source data.	2500
spring.boot.admin.ui.poll-timer.gc	Polling duration in milliseconds to fetch new gc data.	2500
spring.boot.admin.ui.poll-timer.process	Polling duration in milliseconds to fetch new process data.	2500
spring.boot.admin.ui.poll-timer.memory	Polling duration in milliseconds to fetch new memory data.	2500
spring.boot.admin.ui.poll-timer.threads	Polling duration in milliseconds to fetch new threads data.	2500
spring.boot.admin.ui.poll-timer.logfile	Polling duration in milliseconds to fetch new logfile data.	1000
spring.boot.admin.ui.enable-toasts	Enables or disables toast notifications.	false
spring.boot.admin.ui.title	Browser's window title value.	""
spring.boot.admin.ui.brand	HTML code rendered in the navigation header and defaults to the Spring Boot Admin label. By default, the Spring Boot Admin logo is followed by its name.	""
management.scheme	Value that is substituted in the service URL used for accessing the actuator endpoints.
management.address	Value that is substituted in the service URL used for accessing the actuator endpoints.
management.port	Value that is substituted in the service URL used for accessing the actuator endpoints.
management.context-path	Value that is appended to the service URL used for accessing the actuator endpoints.	${spring.boot.admin.discovery.converter.management-context-path}
health.path	Value that is appended to the service URL used for health checking. Ignored by the EurekaServiceInstanceConverter.	${spring.boot.admin.discovery.converter.health-endpoint}
spring.boot.admin.discovery.enabled	Enables the DiscoveryClient support for the admin server.	true
spring.boot.admin.discovery.converter.management-context-path	Value that is appended to the service-url of the discovered service when the management-url value is converted by the DefaultServiceInstanceConverter.	/actuator
spring.boot.admin.discovery.converter.health-endpoint-path	Value that is appended to the management-url of the discovered service when the health-url value is converted by the DefaultServiceInstanceConverter.	"health"
spring.boot.admin.discovery.ignored-services	Services that are ignored when using discovery and not registered as application. Supports simple patterns such as "foo*", "*bar", and "foo*bar*".
spring.boot.admin.discovery.services	Services included when using discovery and registered as application. Supports simple patterns such as "foo*", "*bar", and "foo*bar*".	"*"
spring.boot.admin.discovery.ignored-instances-metadata	Services ignored if they contain at least one metadata item that matches patterns in this list. Supports patterns such as "discoverable=false".
spring.boot.admin.discovery.instances-metadata	Services included if they contain at least one metadata item that matches patterns in list. Supports patterns such as "discoverable=true".

Common configurations

• Logging related configurations:
  • logging.level.*
  • logging.group.*
  • Any other configurations under logging.* namespace should be forbidden. For example, writing log files by using logging.file should be forbidden.

Related content

Integrate the managed Admin for Spring with Eureka Server for Spring