CredentialRetriever (jib-core 0.27.3 API)

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
```
@FunctionalInterface
public interface CredentialRetriever
```
Retrieves credentials for a registry.

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  java.util.Optional<Credential> retrieve()
  Fetches the credentials.

- Method Detail
  - retrieve
```
java.util.Optional<Credential> retrieve()
                                 throws CredentialRetrievalException
```
    Fetches the credentials. Implementations must be thread-safe.
    Implementations should return Optional.empty() if no credentials could be fetched with this CredentialRetriever (and so other credential retrieval methods may be tried), or throw an exception something went wrong when fetching the credentials.
    
    Returns:
    
    the fetched credentials or Optional.empty() if no credentials could be fetched with this provider
    
    Throws:
    
    CredentialRetrievalException - if the credential retrieval encountered an exception