Spaces Provider

The current implementation in oCIS might not yet fully reflect this concept. Feel free to add links to ADRs, PRs and Issues in short warning boxes like this.

A storage provider manages resources identified by a reference by accessing a storage system with a storage driver.

The oCIS frontend service starts all services that handle incoming HTTP requests:

• ocdav for ownCloud flavoured WebDAV
• ocs for sharing, user provisioning, capabilities and other OCS API endpoints
• datagateway for up and downloads
• TODO: ocm

The ocdav service not only handles all WebDAV requests under (remote.php/)(web)dav but also some other legacy endpoints like status.php:

The correct endpoint for a users home storage space in oc10 is remote.php/dav/files/<username>. In oc10 all requests at this endpoint use a path based reference that is relative to the users home. In oCIS this can be configured and defaults to /home as well. Other API endpoints like ocs and the web UI still expect this to be the users home.

In oc10 we originally had remote.php/webdav which would render the current users home storage space. The early versions (pre OC7) would jail all received shares into a remote.php/webdav/shares subfolder. The semantics for syncing such a folder are not trivially predictable, which is why we made shares freely mountable anywhere in the users home.

The current reva implementation jails shares into a remote.php/webdav/Shares folder for performance reasons. Obviously, this brings back the special semantics for syncing. In the future we will follow a different solution and jail the received shares into a dedicated /shares space, on the same level as /home and /spaces. We will add a dedicated API to list all storage spaces a user has access to and where they are mounted in the users namespace.

TODO rewrite this hint with /dav/spaces Existing folder sync pairs in legacy clients will break when moving the user home down in the path hierarchy like CernBox did. For legacy clients the remote.php/webdav endpoint will no longer list the users home directly, but instead present the different types of storage spaces:

• remote.php/webdav/home: the users home is pushed down into a new home storage space
• remote.php/webdav/shares: all mounted shares will be moved to a new shares storage space
• remote.php/webdav/spaces: other storage spaces the user has access to, e.g. group or project drives

The OCS Share API endpoint /ocs/v1.php/apps/files_sharing/api/v1/shares returns shares, which have their own share id and reference files using a path relative to the users home. They API also lists the numeric storage id as well as the string type storage_id (which is confusing … but yeah) which would allow constructing combined references with a storage space id and a path relative to the root of that storage space. The web UI however assumes that it can take the path from the file_target and append it to the users home to access it.

The API already returns the storage id (and numeric id) in addition to the file id:

    <storage_id>home::auser</storage_id>
    <storage>993</storage>
    <item_source>3994486</item_source>
    <file_source>3994486</file_source>
    <file_parent>3994485</file_parent>
    <file_target>/Shared/Paris.jpg</file_target>

Creating shares only takes the path as the argument so creating and navigating shares only needs the path. When you update or delete a share it takes the share id not the file id.

The OCS service makes a stat request to the storage provider to get a ResourceInfo object. It contains both, a ResourceId and an absolute path. If the resource exists a request is sent to the gateway. Depending on the type of share the Collaboration API, the Link API or the Open Cloud Mesh API endpoints are used.

The user and public share provider implementations identify the file using the ResourceId. The ResourceInfo is passed so the share provider can also store who the owner of the resource is. The path is not part of the other API calls, e.g. when listing shares. The OCM API takes an id based reference on the CS3 api, even if the OCM HTTP endpoint takes a path argument. @jfd: Why? Does it not need the owner? It only stores the owner of the share, which is always the currently logged-in user, when creating a share. Afterwards only the owner can update a share … so collaborative management of shares is not possible. At least for OCM shares.

The reva storage registry manages the CS3 global namespace: It is used by the reva gateway to look up address and port of the storage provider that should handle a reference.