configurable endpoints:
https://github.com/spring-cloud/spring-cloud-aws/issues/333
    https://stackoverflow.com/questions/51235554/spring-cloud-aws-set-endpoint
vpc:
https://github.com/spring-cloud/spring-cloud-aws/issues/152

https://cloud.spring.io/spring-cloud-aws/reference/html/#parameter-store-and-secrets-manager-configuration-credentials-and-region-configuration
    The Parameter Store and Secrets Manager Configuration support uses a bootstrap context to configure a default
    AWSSimpleSystemsManagement client, which uses a com.amazonaws.auth.DefaultAWSCredentialsProviderChain
    and com.amazonaws.regions.DefaultAwsRegionProviderChain.
    If you want to override this, then you need to define your own Spring Cloud bootstrap configuration class with a bean
    of type AWSSimpleSystemsManagement that’s configured to use your chosen credentials and/or region provider.
    Because this context is created when your Spring Cloud Bootstrap context is created,
    you can’t simply override the bean in a regular @Configuration class.


https://aws.amazon.com/premiumsupport/knowledge-center/access-key-does-not-exist/
    https://github.com/minio/minio/blob/master/cmd/iam.go
    https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_use_switch-role-ec2_instance-profiles.html

@Retention(RetentionPolicy.RUNTIME)
@Import(ContextCredentialsConfigurationRegistrar.class)
@Target(ElementType.TYPE)
public @interface EnableContextCredentials {

By default we use
ContextCredentialsAutoConfiguration {
    ...
    @Override
    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
        // Do not register a credentials provider if a bean with the same name is already registered.
        if (registry.containsBeanDefinition(CredentialsProviderFactoryBean.CREDENTIALS_PROVIDER_BEAN_NAME)) {
                return;
        }
        ...
    }
    ...
}

public class CredentialsProviderFactoryBean extends AbstractFactoryBean<AWSCredentialsProvider> {
    /**
     * Name of the credentials provider bean.
     */
    public static final String CREDENTIALS_PROVIDER_BEAN_NAME = "credentialsProvider";
    ...
}

https://cloud.spring.io/spring-cloud-aws/reference/html/#parameter-store-and-secrets-manager-configuration-credentials-and-region-configuration
    !!!

https://cloud.spring.io/spring-cloud-aws/reference/html/#using-cloudformation-3
    ??? ... Application developers can use the org.springframework.cloud.aws.core.env.ResourceIdResolver interface to resolve the physical names that are generated based on the logical names.