`@VaultPropertySource` fails with `NoSuchMethodException`

Describe the bug

Code with @VaultPropertySource @Value that works with spring-cloud-vault before version 3.0; fails to work since 3.0 (haven't noticed any information regarding breaking change in release notes).

Versions used

spring-boot-starter-parent : 2.6.6
spring-cloud-dependencies : 2021.0.0 | spring-cloud-vault : 3.1.0

So, the below code stopped working and throw an exception

@Configuration
@VaultPropertySource(value = "secret/app/user", propertyNamePrefix = "user.")
public class UserConfig {

  @Value("${user.value}")
  private String userName;

  ....
}

Exception thrown

Caused by: java.lang.NoSuchMethodException: org.springframework.cloud.vault.config.VaultAutoConfiguration.\<init>()

Work Around for version >=3.0 Before spring-cloud-vault 3.0 (before ConfigData API) using @VaultPropertySource with @Value was straightforward but since 3.0 spring.config.import seems to be mandatory; if there is at least one VaultPropertySource configured with the spring.config.import properties in application.yml then all other @VaultPropertySource seem to be automatically working.

 spring.config.import:vault://secrets/app/user?path=user

@Configuration
@VaultPropertySource(value = "secret/app/user", propertyNamePrefix = "user.")
public class UserConfig {

  @Value("${user.value}")
  private String userName;

  ....
}

@Configuration
@VaultPropertySource(value = "secret/app/token", propertyNamePrefix = "token.")
public class TokenConfig {

  @Value("${token.value}")
  private String tokenValue;

  ....
}

The reason could be that without spring.config.import Spring Cloud Vault thinks ConfigData API isn't enabled and tries to use VaultAutoConfiguration, which fails.

Going forward (version > 3.*) is there a better way to use @VaultPropertySource

Expected Since documentation doesn't point at any breaking changes I expected no code changes are needed in my project when using the newer version or ConfigData API.

(I'm sorry if I'm missing any information and if this isn't an actual bug then any guidance on how to use @VaultPropertySource with the newer version would be appreciated)

After investigating the issue, we recommend using @VaultPropertySource in combination with AbstractVaultConfiguration to provide the required infrastructure separately from auto-configuration.

With version 3.0 of Spring Cloud Vault, all bootstrap configuration went into regular auto-configuration hence there is no longer a bootstrap context that hosts components required for Vault. The property source registration of @VaultPropertySource aims to provide config data as early as possible so downstream beans can consume secrets. If we delayed property source registration to a bean postprocessor, then we would resolve the problem of instantiating VaultAutoConfiguration. At the same time, we would not be able to provide secrets during bean bootstrapping and potential components that require property values from Environment would not see vault secrets until the context refresh has finished.

TL;DR: Delaying property source registration would render @VaultPropertySource useless.

This leaves users with two options:

Using AbstractVaultConfiguration by providing all configuration early on
Using Config Data imports via spring.config.import=vault://secrets/app/user?path=user

spring-cloud / spring-cloud-vault

`@VaultPropertySource` fails with `NoSuchMethodException` #642