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

Article
11/18/2024

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

To finish this project, you need the following items:

Requirement	Instructions
Azure account	An active subscription is required. If you don't have one, you can create one for free.
Azure CLI	Install the 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 1Gi.
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. Once 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
Azure portal

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

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

export LOCATION=chinaeast
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.

az cloud set -n AzureChinaCloud
az login
# az cloud set -n AzureCloud   //means return to Public Azure.

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.

Create your container app environment.

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

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

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

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.

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

Property Value

Environment name Enter my-environment.

Zone redundancy Select Disabled.
Select Create, and then select the Container tab.

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

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.

Select the Ingress tab.
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.
Select Review + create.
After the validation checks pass, select Create to create your container app.

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

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.

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

Update 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 2 \
  --max-replicas 2

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

Go to your container app's environment in the portal.
On the service menu, under Services, select Services.
Select the + Configure dropdown, and select Java component.
On the Configure Java component pane, enter the following values:

Property Value

Java component type Select Admin for Spring.

Java component name Enter admin.
Select Next.
On the Review tab, select Configure.

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

Bind your container app to the Admin for Spring Java component

Azure CLI
Azure portal

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

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
Azure portal

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

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.

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.

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 -o tsv)

Assign the role to your account.

Before you run this command, replace the placeholder in between the <> brackets with your user or service principal ID.
```
az role assignment create \
  --assignee <USER_OR_SERVICE_PRINCIPAL_ID> \
  --role "<ROLE_NAME>" \
  --scope $ENVIRONMENT_ID
```
Note

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

Next step

Configure Admin for Spring settings

Integrate the managed Admin for Spring with Eureka Server for Spring