Azure Spring Cloud enables you to easily run a Spring Boot based microservices application on Azure.

This quickstart shows you how to deploy an existing Java Spring Cloud application to Azure. When you're finished, you can continue to manage the application via the Azure CLI or switch to using the Azure portal.

You will:

• Build an existing application locally
• Provision an Azure Spring Cloud service instance
• Deploy the application to Azure
• Open the application

In order to deploy a Java app to cloud, you need an Azure subscription. If you do not already have an Azure subscription, you can activate your MSDN subscriber benefits or sign up for a free Azure account.

In addition, you will need the following:

| Azure CLI version 2.0.67 or higher | Java 11 | Gradle | Git |

Create an instance of Azure Cache for Redis Enterprise: | Step-by-step directions | Start here https://aka.ms/redis-enterprise which includes preview feature flag |

Important: Enable the 'redisearch' module from the Advanced tab during the creation process.

Install the Azure Spring Cloud extension for the Azure CLI using the following command

    az extension add --name spring-cloud

    mkdir source-code
    git clone https://github.com/selvasingh/brewdis

    cd brewdis
    ./gradlew build

This will take a few minutes.

Create a bash script with environment variables by making a copy of the supplied template:

    cp .scripts/setup-env-variables-azure-template.sh .scripts/setup-env-variables-azure.sh

Open .scripts/setup-env-variables-azure.sh and enter the following information:

    export SUBSCRIPTION=subscription-id # customize this
    export RESOURCE_GROUP=resource-group-name # customize this
    ...
    export SPRING_CLOUD_SERVICE=azure-spring-cloud-name # customize this
    ...
    export SPRING_REDIS_HOST=redis-server-host # customize this
    export SPRING_REDIS_PASSWORD=redis-password # customize this

Then, set the environment:

    source .scripts/setup-env-variables-azure.sh

Login to the Azure CLI and choose your active subscription. Be sure to choose the active subscription that is whitelisted for Azure Spring Cloud

    az login
    az account list -o table
    az account set --subscription ${SUBSCRIPTION}

Prepare a name for your Azure Spring Cloud service. The name must be between 4 and 32 characters long and can contain only lowercase letters, numbers, and hyphens. The first character of the service name must be a letter and the last character must be either a letter or a number.

Create a resource group to contain your Azure Spring Cloud service.

    az group create --name ${RESOURCE_GROUP} \
        --location ${REGION}

Create an instance of Azure Spring Cloud.

    az spring-cloud create --name ${SPRING_CLOUD_SERVICE} \
        --resource-group ${RESOURCE_GROUP} \
        --location ${REGION}

The service instance will take around five minutes to deploy.

Set your default resource group name and cluster name using the following commands:

    az configure --defaults \
        group=${RESOURCE_GROUP} \
        location=${REGION} \
        spring-cloud=${SPRING_CLOUD_SERVICE}

Create Spring Cloud microservice retail app.

    az spring-cloud app create --name ${APP_NAME} --instance-count 1 --is-public true \
        --memory 2 \
        --runtime-version Java_11 \
        --jvm-options='-Xms2048m -Xmx2048m'

Deploy the application to Azure.

    az spring-cloud app deploy --name ${APP_NAME} \
        --jar-path ${BREWDIS_JAR} \
        --env SPRING_REDIS_HOST=${SPRING_REDIS_HOST} \
              SPRING_REDIS_PASSWORD=${SPRING_REDIS_PASSWORD} \
              SPRING_REDIS_PORT=${SPRING_REDIS_PORT} \
              STOMP_HOST=${STOMP_HOST} \
              STOMP_PORT=${STOMP_PORT}

    az spring-cloud app show --name ${APP_NAME} | grep url

Navigate to the URL provided by the previous command to open the brewdis application.

When viewing the application you will find that if you are a user of the Edge browser, then you will see the availability count shown on the catalog page. We are testing out this new feature, and to start with we are just targeting users of the Edge browser.

boolean showAvailabilityCount = featureManager.isEnabledAsync("beta").block();

This is done by using a Feature Flag and a Feature Filter to check which browser is being used. This is a custom Feature Filter that was designed to target 1 of 3 browsers, Edge, Firefox, and Chrome, depending on the configuration.

public class BrowserFilter implements FeatureFilter {

    @Autowired
    private HttpServletRequest request;

    @Override
    public boolean evaluate(FeatureFilterEvaluationContext context) {
        String userAgent = request.getHeader(USERAGENT);
        String browser = (String) context.getParameters().get(BROWSER);
        if (userAgent.contains(EDGE_USERAGENT) && browser.equals(EDGE_BROWSER)) {
            return true;
        } else if (userAgent.contains(FIREFOX_USERAGENT) && browser.equals(FIREFOX_BROWSER)) {
            return true;
        } else if (userAgent.contains(CHROME_USERAGENT) && !userAgent.contains(EDGE_USERAGENT)
                && browser.equals(CHROME_BROWSER)) {
            return true;
        }
        return false;
    }
}

Additional information on how to use Feature Flags can be found here.

In addition to managing Feature Flags from a config file, they also can be stored and updated from Azure App Configuration.

1. Create a new Azure App Configuration store

az appconfig create -l ${REGION} -g ${RESOURCE_GROUP} --sku standard -n ${APP_NAME}-config

1. Create config store endpoint environment variable from the value given in the previous step

export CONFIG_STORE_ENDPOINT={YOUR_ENDPOINT_VALUE}

1. In the Azure Portal go to your Azure Spring Cloud instance, select Apps, your app, under Settings select Identity, then switch the Status toggle to On.

2. In the Azure Portal go to your new App Configuration instance, select Access control (IAM), + Add, Add role assignment.

   1. Select App Configuration Data Reader as the role

   2. In select enter {Azure Spring Cloud resource name}/apps/{App Name}, example brewdis/apps/retail. Note: If no value is found close the side bar, wait a moment and reselect + Add, then Add role assignment.

   3. Select Save.

3. Upload the first Feature Flag from the CLI

az appconfig kv import -n ${APP_NAME}-config -s file --path data/featureflag.yml --format yaml

Your Feature Flag has now been added to Azure App Configuration. You can view it in the portal by going to your App Configuration instance, and selecting Feature manager. Here you will see a key beta, which is your feature flag and it currently has a state of conditional. If you right click on the row and select edit you will see the feature flag information.

Here there is a list of feature filters, currently only browserFilter. Selecting the ... and selecting Edit parameters you will see the conditions used to trigger the feature flag. This is currently set to browser and edge. For this filter the valid values are; edge, chrome, and firefox.

To modify the condition update the value column and select Apply in the Edit parameters pane, then Apply again in the edit pane.

If your application is currently running, refreshing the page twice will allow the new feature flag to take effect. The first refresh is activity on the application to allow for a refresh to be triggered, the second one will update the page with the new feature flag. If no change happens this can be caused by the system cache of the feature flag value, by default this value is 30 seconds. Waiting 30 seconds and again twice refreshing the page will allow the value to be updated.

You can open the log stream from your development machine.

    az spring-cloud app logs -f -n ${APP_NAME}

If you do not have a Key Vault yet, run the following commands to provision a Key Vault:

    export KEY_VAULT=your-keyvault-name # customize this
    az keyvault create --name ${KEY_VAULT} -g ${RESOURCE_GROUP}

Create a service principal with enough scope/role to manage your Azure Spring Cloud resource group:

    az ad sp create-for-rbac --role contributor --scopes /subscriptions/<SUBSCRIPTION_ID>/resourceGroups/<RESOURCEGROUP_ID> --sdk-auth

With results:

    {
        "clientId": "<GUID>",
        "clientSecret": "<GUID>",
        "subscriptionId": "<GUID>",
        "tenantId": "<GUID>",
        "activeDirectoryEndpointUrl": "https://login.microsoftonline.com",
        "resourceManagerEndpointUrl": "https://management.azure.com/",
        "sqlManagementEndpointUrl": "https://management.core.windows.net:8443/",
        "galleryEndpointUrl": "https://gallery.azure.com/",
        "managementEndpointUrl": "https://management.core.windows.net/"
    }

Add this service principle as a secret named AZURE-CREDENTIALS-BREWREDIS-PROD to your Key Vault, along with SPRING-REDIS-HOST and SPRING-REDIS-PASSWORD.

To generate a key to access the Key Vault, execute command below:

    az ad sp create-for-rbac --role contributor --scopes /subscriptions/<SUBSCRIPTION_ID>/resourceGroups/<RESOURCE_GROUP>/providers/Microsoft.KeyVault/vaults/<KEY_VAULT> --sdk-auth

Then, follow the steps here to add access policy for the Service Principal.

In the end, add this service principal as secrets named "AZURE_KEY_VAULT" in your forked GitHub repo following the steps here.

Finally, edit the workfolw file .github/workflows/app.yml in your forked repo to fill in the names of resource group and the Azure Spring Cloud instance name that you just created:

    env:
      RESOURCE_GROUP: brewdis-prod # customize this
      SPRING_CLOUD_SERVICE: brewdis-spring-cloud # customize this
      SPRING_CLOUD_APP: brewdis-storefront # customize this

After you commited this change, you will see GitHub Actions triggered to build and deploy the brewdis-api app to your Azure Spring Cloud instance.

In this quickstart, you've deployed an existing Spring Boot application using Azure CLI. To learn more about Azure Spring Cloud, go to:

• Azure Spring Cloud
• Azure Spring Cloud docs
• Deploy Spring microservices from scratch
• Deploy existing Spring microservices
• Azure for Java Cloud Developers
• Spring Cloud Azure
• Spring Cloud