Added improved providervalidation logic which tests for read-after-write
property between connections. The new test was failing before the change
and is now passing for Google Drive, OneDrive and DropBox.
Also simplified validation test suite, which will simply test whether
the provider supports DoNotRecreate or properly rejects it without
external configuration.
* Add a new PutBlob option and blob error type
When `DoNotRecreate` is set as true, the blob put operation should
only succeed if no blob with the given blob ID already exists.
Othwerwise, `ErrBlobAlreadyExists` is returned.
* Validate default storage providers' support
By default, storage providers should not support idempotent creates.
This commit adds error handling to exit early if `DoNotRecreate` is
set to true. The commit also verifies this behavior in the provider
validation test.
* Implement support for new option in GCS storage
* Push PutBlob option handling down to Impl
When PutBlob options were introduced, error handling logic for them
was implemented for the Sharded storage interface. However, the
behavior of different providers that implement Sharded can be
different, so it's better to push the options down to be processed in
the provider implementations.
* Introduce new error type for unsupported put opts
To unify error handling code and make it more maintainable, introduce
a new error type `blob.ErrUnsupportedPutBlobOption`, which is to be
returned whenever a storage provider implementation is given put
options it does not support.
* cli: added 'repository validate-provider' which runs a set of tests against blob storage provider to validate it
This implements a provider tests which exercises subtle behaviors which are not always correctly implemented by providers claiming compatibility with S3, for example.
The test checks:
- not found behavior
- prefix scans
- timestamps
- write atomicity
* retry: improved error message on failure
* rclone: fixed stats reporting and awaiting for completion
* webdav: prevent panic when attempting to mkdir with empty name
* testing: run providervalidation.ValidateProvider as part of regular provider tests
* cli: print a recommendation to validate provider after repository creation
