how to configure vcap.services property for mtar deployment of spring boot application on SAP CloudFoundry? - sap-cloud-platform

Question

I am working on a Spring Boot application using SAP Cloud SDK for Java and deploying the application on SAP CloudFoundry.
The application is dependent on a user provided service for configuration and we can access this service using vcap.services property.
An example of the manifest.yml that is working for me is as below.
---
applications:
- name: some-app-name
buildpacks:
- sap_java_buildpack
env:
SPRING_CLOUD_CONFIG_URI: ${vcap.services.config-server-uri.credentials.uri}
services:
- config-server-uri
In the above manifest.yml, config-server-uri is the name of the service and the application environment variable SPRING_CLOUD_CONFIG_URI derives the value using ${vcap.services.config-server-uri.credentials.uri}.
Now, I want to deploy the same above as MTAR application on SAP Cloud platform Cloud Foundry.
To achieve this, I configured mta.yml as below.
ID: some_id
_schema-version: '2.1'
description: some description
version: 0.0.1
parameters:
keep-existing-routes: true
modules:
- name: some-app-name
type: java
properties:
SPRING_CLOUD_CONFIG_URI: ${vcap.services.config-server-uri.credentials.uri}
requires:
- name: config-server-uri
resources:
- name: config-server-uri
type: org.cloudfoundry.user-provided-service
However, deployment with the above mta.yml configuration fails as ${vcap.services.config-server-uri.credentials.uri} for SPRING_CLOUD_CONFIG_URI could not be resolved.
Instead, if I replace ${vcap.services.config-server-uri.credentials.uri} with the actual url, mtar deployment of the application works fine.
Can anyone please guide me here on what am I doing wrong and how to configure/access vcap.services property in mta.yml for mtar deployment?

Answer 1

I would recommend to not read/map this environment variable as part of the manifest.yml or the mta.yml but read the value as part of your Spring application, for example using a bootstrap.yml.
The following link also provides an example how to configure it for Cloud Foundry:
https://cloud.spring.io/spring-cloud-config/multi/multi__spring_cloud_config_client.html#_security_2
If you deploy your apps on Cloud Foundry, the best way to provide the password is through service credentials (such as in the URI, since it does not need to be in a config file). The following example works locally and for a user-provided service on Cloud Foundry named configserver:
bootstrap.yml
spring:
cloud:
config:
uri: ${vcap.services.configserver.credentials.uri:http://user:password#localhost:8888}