spring-boot-mutlitenancy-app

Description

This is a test project about implementing Java backend microservices on SAP BTP Cloud Foundry Platform.

Project details

• Guide to developing cloud applications using SAP Cloud Platform and Cloud Foundry.
• Spring-Boot Crud operations
• Deployment on Cloud Foundry (SAP BTP)
• O-Auth 2.0 protocol (XSUAA service)
• SaaS multi-tenant application (Schema isolation), saas-registry service

Create an Application with SAP Java Buildpack

Simple Java application by using cf CLI via Spring Boot.

• This simple app will be invoked through a web microservice (application router).
• This app will set authentication checks and an authorization role to properly access your web application.

Add XSUAA authorisation service:

cf create-service xsuaa application xsuaa-service -c xs-security.json
cf unbind-service 'app_name' xsuaa-service cf delete-service 'xsuaa-service'

Where:

• 'xsuaa-service' is name of xsuaa service in SAP BTP
• 'application' is an application name

Build project:

1. In 'web' run commands which will create package.json and add approuter service:

npm init
npm install @sap/approuter --save

2. In the root run:

mvn clean install

Deploy app to SAP BTP Cloud Foundry:

1. Set the Cloud Foundry API endpoint for your subaccount on SAP BTP:

cf api https://api.cf.eu20.hana.ondemand.com
cf login or cf login --sso

2. Deploy java application on SAP BTP Cloud Foundry:

mvn clean install cf push

Using Postman for API Testing with XSUAA

Read values from the environment variable of the application:

cf env app_name

• open Postman

• create Get request

• http field: put link on approuter from BTP Cloud Foundry

• authorisation tab:

• • Grant Type: 'Password credential'
• • Access Token URL = xsuaa[0].credentials.url + "/oauth/token"
• • Client ID = xsuaa[0].credentials.clientid
• • Client Secret = xsuaa[0].credentials.clientsecret
• • Scope = xsuaa[0].credentials.xsappname + ".admin"

Useful commands:

cf logs cf logs --recent //show logs from SAP BTP
cf marketplace //show available services
cf marketplace -s postgresql //show info about one service
cf events //show events cf create-service postgresql v9.6-dev postgres cf bind-service //connect two services

cf services //show services in your dev spase
cf apps //show downloaded apps cf app //show statistics

Add log service from SAP BTP

cf marketplace
cf create-service application-logs lite 'myapplogs'
cf services
cf bind-service 'appname' 'myapplogs'
cf restage 'appname'

Persistence

Deep Dive 6 with SAP Cloud SDK: Extend your Cloud Foundry Application with Tenant-Aware Persistency

cf create-service postgresql-db trial postgres-instance cf bind-service sbtp postgres-instance //if you write it in manifest then ut will be automatically cf restage sbtp

where:

• sbtp is APP_NAME in BTP CLoud Foundry
• postgresql-db <- name from: cf marketplace
• trial <- your plan in BTP Cockpit
• postgres-instance <- name of your new instance 'postgresql-db'

Connect to database running on Cloud Foundry locally through ssh:

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1. Activate SSH for your app:

cf enable-ssh sbtp

2. Create a service key for your service instance using the cf create-service-key command:

cf create-service-key <service_instance_name_in_BTP> <my_new_key_name>

3. Retrieve your new service key using the cf service-key command:

cf service-key <service_instance_name_in_BTP> <my_new_key_name>

4. Open SSH connection:

cf ssh -L <local_port>:<service_hostname>:<service_port> <app_name>
like:
cf ssh -L 63306:postgres-ade9561e-2985-4c20-b601-097eee32029a.cqryblsdrbcs.us-east-1.rds.amazonaws.com:4605 sbtp

• <local_port> is available local port for port forwarding. For example, 63306
• <service_hostname> is the address provided under hostname in the service key retrieved earlier.
• <service_port> is the port provided under port.
• <app_name> is the name of your app in SAP BTP.

5. Access your service instance from Intelij Idea

Add Multi-tenancy

1. Add SaaS Provisioning service Create config.json is a configuration file for SaaS Provisioning service

{
  "xsappname":"helloworld",
  "appUrls": {
    "onSubscription" : "https://helloworld-ap25.cfapps.eu10.hana.ondemand.com/callback/v1.0/tenants/{tenantId}"
  },
  "displayName" : "Helloworld MTA",
  "description" : "Helloworld MTA sample application",
  "category" : "Custom SaaS Applications"
}

Create the SaaS Provisioning service instance with the config.json file:

cf create-service saas-registry application saas-registry-instance -c config.json

2. Create a route for a consumer subaccount:

cf map-route 'approuter_name' cfapps.us10-001.hana.ondemand.com --hostname 'subaccount_subdomain'-'first_part_of_approuter_rout'

Debug an Application Running on SapMachine:

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1. Configure application for debugging. Add setting to manifest.yaml:

JBP_CONFIG_JAVA_OPTS: "[java_opts: '-agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n,onjcmd=y']"
env:
  JBP_CONFIG_SAP_MACHINE_JDK: "[default_debug_agent_active: true]"

2. Redeploy application:

cf push

3. Enter in file system of a remote app:

cf ssh < app name >

4. Move to 'bin' directory:

cd app/META-INF/.sap_java_buildpack/sap_machine_jdk/bin

5. Run the following command to found $JAVA_PID of debug process:
   'META-INF/.sap_java_buildpack/sap_machine_jdk/bin/java'

ps aux
exit

6. Start the debug process. Replace $JAVA_PID on your number, and <app_name>:

cf ssh sbtp -c "export JAVA_PID=ps java pid= && app/META-INF/.sap_java_buildpack/sap_machine_jdk/bin/jcmd $JAVA_PID VM.start_java_debugging"

7. Open SSH connection to debug process:

cf ssh -N -T -L 8000:localhost:8000 <app_name>

8. Edit configuration for the debug process in Intellij IDEA:

Mutlitenancy testing using by Postman

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1. Prepare request like this [Using Postman for API Testing with XSUAA]

https://sbtp-app-rout.cfapps.us10-001.hana.ondemand.com

2. Delete scope
3. Change 'Grand Type' to 'Client credentials'
4. Expand 'advanced' and create parameter x-zid, value is a subaccount tenant ID in CF:
   
5. Get token for current tenant and use it on route of application (You can parse your token by JWT.io, and check "x-zid" section to make sure that you have correct tenantId):

https://sbtp-app-rout.cfapps.us10-001.hana.ondemand.com/books

Migration from manifest.yaml to mtad.yaml

Tests generation using plugin Sapient AI

Home page Installation and Documentation

Additional resources:

1. Fundamentals of Multitenancy in SAP BTP
2. Guide to Developing Cloud Applications with SAP Cloud Platform and Cloud Foundry
3. Remote Debugging on Cloud Foundry