Server-side blobs

The server-side implementation of blobs provides HTTP APIs for data storage using a filesystem backend.

HTTP APIs

Soledad Server provides two different REST APIs for interacting with blobs:

• A Public Blobs HTTP API, providing the Blobs service for Soledad Client (i.e. actual users of the infrastructure).
• A Local Incoming Box HTTP API, providing the delivery part of the Incoming Box service, currently used for the MX mail delivery.

Authentication is handled differently for each of the endpoints, see Authentication for more details.

Filesystem backend

On the server side, all blobs are currently stored in the filesystem, under /var/lib/soledad/blobs by default. Blobs are split in subdirectories according to the user’s uuid, the namespace, and the 1, 3 and 6-letter prefixes of the blobs uuid to prevent too many files in the same directory. A second file with the extension .flags stores the flags for a blob.

As an example, a PUT request to /blobs/some-user-id/some-blob-id would result in the following filesystem structure in the server:

/var/lib/soledad/blobs
└── some-user-id
    └── default
        └── s
            └── som
                └── some-b
                    ├── some-blob-id
                    └── some-blob-id.flags