bootstrap.yml configuration not processed anymore with Spring Cloud 2020.0

I spent a whole day trying to resolve this issue. For everyone who is following any outdated cloud tutorials:- from springboot 2.4 bootstrap starter dependency has to be added, to follow along the tutorial to use bootstrap.properties (bootstrap.yml) for external configuration.

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-bootstrap</artifactId>
</dependency>

As pointed put by Nicoll, With Spring Cloud Vault 3.0 and Spring Boot 2.4, the bootstrap context initialization (bootstrap.yml, bootstrap.properties) of property sources was deprecated. This can be fixed in one of the 2 ways

1. Use Spring Boot 2.4.0 Config Data API to import configuration from Vault (Preferred)
2. Legacy Processing: Enable the bootstrap context either by setting the configuration property spring.cloud.bootstrap.enabled=true or by including the dependency

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-bootstrap</artifactId>
</dependency>

1. Use Spring Boot 2.4.0 Config Data API (Preferred)

Move bootstrap.yml configuration to application.yml and updated file looks like below

application.yml

spring:
  cloud:
    vault:
      authentication: APPROLE
      app-role:
        role-id: ${role-id}
        secret-id: ${secret-id}
        role: pres-read
        app-role-path: approle
      uri: ${vault-server}
      connection-timeout: 5000
      read-timeout: 15000
  config:
    import: vault://secret/app/pres/

And define individual profiles as shown below. Add spring.config.import: vault://secret/app/pres/demo property.

application-demo.yml

## Server Properties
server:
  port: 8081

spring:
  config:
    import: vault://secret/app/pres/demo
  datasource:
    username: ${pres.db.username}
    password: ${pres.db.password}
    url: ${pres.db.url}
    driver-class-name: com.mysql.cj.jdbc.Driver

Repeat the same process for all profiles like dev, test, qc, staging and prod.

2. Legacy Processing:

Add the following dependency if you still want to use bootstrap.yml

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-bootstrap</artifactId>
</dependency>

to the project. The issue will be resolved.

See Spring Cloud Vault docs for more information