Deploy CAP Java App to SAP Business Technology Platform

You first need to provision your SAP HANA Cloud instance, which is a prerequisite to later on create a SAP HANA HDI Container to deploy your database artifacts to.

1. Follow the tutorial Provision an Instance of SAP HANA Cloud (Step 1+2). Make sure to allow access to your SAP HANA Cloud from all IPs and that the instance of the SAP HANA you have created is mapped to your subaccount and space (Step 1) where you working with this tutorial.

1. To prepare the project, execute the following in the root level of your project:

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   cds add hana,mta,xsuaa,approuter --for production
   

   --for production adds all configuration added by this command in the .cdsrc.json file into a requires.[production] block.

   hana configures deployment for SAP HANA, so a data source of type hana is added in the requires.[production].db block.

   mta adds the mta.yaml file. This file reflects your project configuration.

   xsuaa creates an xs-security.json and also the needed configuration in the mta.yaml file. An authentication of kind xsuaa is added in the requires.[production].auth block.

   approuter adds the configuration and needed files for a standalone AppRouter so that the authentication flow works after deployment.

   Learn more about those steps in the Deploy to Cloud Foundry guide in the CAP documentation.

2. (Optional) Following this tutorial strictly, you don’t have an own UI yet in your project. To enable the index page with SAP Fiori preview, add the following configuration in the application.yaml of your bookstore project in VS Code:

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   ---
   spring:
     config.activate.on-profile: cloud
   cds:
     index-page.enabled: true
   

   Setting cds.index-page.enabled: true turns on the generated index page and the SAP Fiori preview in production mode, just like you’ve seen in your local application in previous tutorials. These features are designed to assist you during development and should not be used in productive applications.

When you’ve followed the previous tutorials, you’ve already added this dependency and can skip this step.

Cloud Foundry uses the Open Service Broker API to provide services to applications. When running your application on Cloud Foundry, an environment variable VCAP_SERVICES is available, which contains all required service credentials. CAP Java can automatically read this environment variable and configure your application to use the SAP HANA database. In addition you want to make sure that your application is secure by default, when you deploy it to the cloud. The required dependencies for these aspects are included in the cds-starter-cloudfoundry dependency bundle, which you added in the previous tutorial.

1. Check the pom.xml in the srv directory (not the pom.xml file located in the root project folder) and under the <dependencies> that the cds-starter-cloudfoundry dependency is there.
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   <dependency>
       <groupId>com.sap.cds</groupId>
       <artifactId>cds-starter-cloudfoundry</artifactId>
   </dependency>
   

The XSUAA security descriptor (xs-security.json) that describes the roles for your application can be generated from your CDS service definitions. It is used to configure your XSUAA service instance and has been generated using the CDS facet cds add xsuaa in a previous step.

1. Open the xs-security.json file in SAP Business Application Studio and update the file so it looks like that:
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   {
     "xsappname": "bookstore",
     "tenant-mode": "dedicated",
     "scopes": [
       {
         "name": "$XSAPPNAME.Administrators",
         "description": "Administrators"
       }
     ],
     "attributes": [],
     "role-templates": [
       {
         "name": "Administrators",
         "description": "generated",
         "scope-references": [
           "$XSAPPNAME.Administrators"
         ],
         "attribute-references": []
       }
     ],
     "role-collections": [
       {
         "name": "BookStore_Administrators",
         "description": "BookStore Administrators",
         "role-template-references": ["$XSAPPNAME.Administrators"]
       }
     ],
     "oauth2-configuration": {
       "redirect-uris": ["https://*.cfapps.us10-001.hana.ondemand.com/**"]
     }
   }
   

   You added the name of your application in the attribute xsappname and declared a role collection to which you can assign users later.

   The value of the last attribute “oauth2-configuration” depends on the landscape where your account is deployed. Check the API URL returned by the command cf target and change data center ID in the value https://*.cfapps.**us10-001**.hana.ondemand.com/** accordingly.

The Cloud Foundry API endpoint is required so that you can log on to your SAP BTP Cloud Foundry space through Cloud Foundry CLI in the next step.

1. Go to SAP BTP Trial Cockpit and choose Go To Your Trial Account.

   

2. Navigate to your subaccount by hitting the corresponding tile.

   

3. Copy the Cloud Foundry API endpoint value as you will need it in the next step.

   

1. In SAP Business Application Studio, open a terminal by choosing Terminal → New Terminal from the main menu.

2. Run the following command to configure which Cloud Foundry environment you want to connect to in the terminal. Replace <CF_API_ENDPOINT> with the actual value you obtained in the previous step.

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   cf api <CF_API_ENDPOINT>
   

3. Authenticate using your login credentials using the following command in the terminal:

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   cf login
   

SAP provides an application format that respects the single modules and their technologies and keeps those modules in the same lifecycle: Multitarget Application

The MBT Build tool uses the mta.yaml file that has been created using cds add mta before, to build the deployable archive. The MultiApps CF CLI plugin adds the deploy command and orchestrates the deployment steps.

1. In the root of your project, execute the following command to build the archive.

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   mbt build -t gen --mtar mta.mtar
   

   For this you need the MBT Build Tool, which SAP Business Application Studio has already installed.

   The -t option defines the target folder of the build result as the gen folder of your project. As part of this build implicitly cds build --production is executed. This implicit build uses then all the configuration you’ve added in the step 1.2 when using --for production.

2. Deploy the archive using cf deploy.

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   cf deploy gen/mta.mtar
   

   For this you need the MultiApps CF CLI plugin, which SAP Business Application Studio has already installed.

   During deployment all needed service instances are created and the applications as well as database artifacts are deployed.

   This process takes some minutes. In this one step the archive is uploaded to Cloud Foundry, service instances are created, the applications are staged, and then deployed to their target runtimes.

   If your deployment fails during deploy of bookstore-db-deployer, make sure that your IP address is configured for connections to SAP HANA Cloud. Or allow connections to all IP addresses at your own risk. We recommend to revert that setting after you’ve completed the tutorial.

3. In the deploy log, find the application URL of bookstore:

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   Application "bookstore" started and available at "[org]-[space]-bookstore.cfapps.[region].hana.ondemand.com"
   

   This is the URL of the AppRouter, which enforces the authentication flow.

4. Open this URL in the browser and try out the provided links, for example, odata/v4/BooksService/Books. Application data is fetched from SAP HANA.

5. Observe that your application is now secured by requiring authentication on service and entity endpoints. In the following tutorials you will learn how to configure authentication and authorization in the cloud.