Davros File Storage

Davros lets you store all of your files in the cloud and sync them between your devices.

!Screenshot of Davros

Davros is built to run inside Sandstorm, an open source web application platform. You can either run Sandstorm yourself or let someone else host it for you.

Installation

• Set up Sandstorm
• Download the latest release and upload it to your Sandstorm server.

Development

Davros is built using Node.js and Ember.js. To run locally, you'll need to install node.js. We also recommend that you use yarn to install dependencies since that will lock versions to the ones that are used during deployment.

To install yarn run npm install -g yarn Then:

• yarn install
• yarn dev

In development, you can connect your desktop client to the backend URL (default http://localhost:8000/) with any username and password.

Office document previews

Previews are converted on the server into selectable PDFs using davros-preview. Supported formats are Microsoft Word (.doc, .docx), Excel (.xls, .xlsx), PowerPoint (.ppt, .pptx), and OpenDocument (.odt, .ods, .odp). The browser's built-in PDF viewer handles display, text selection, search, and page navigation. No Office parser or worker runs in the web app. A browser with PDF viewing enabled is required. Conversion finishes before display; cached PDFs support byte-range requests so the browser can fetch pages as needed. Spreadsheet pages expand to fit all columns at their natural size, retaining vertical pagination instead of splitting columns across pages or applying print-to-fit scaling.

yarn fetch:native-preview downloads the Linux amd64 davros-preview v0.3.4 release, verifies its pinned SHA-256, and installs the binary, fonts, and licenses under output/native-preview. Downloads are cached in tmp/ and verified on reuse. The Sandstorm build and CI use the same script; Rust is no longer needed to build Davros. Converter source, patches, and release tooling live in davros-preview. yarn build:server builds the HTTP server separately.

Only Liberation Sans, Serif, and Mono are packaged, with regular, bold, italic, and bold italic faces. Font substitution can change line wrapping and pagination; CJK and other scripts outside these fonts' coverage are not supported by this minimal font set. Text in images remains an image. The office2pdf build omits its embedded font packs, DOCX dispatch, and PDF merge/split CLI; local spreadsheet patches fix percentage precision, fractional zero-padding, and namespace-prefixed SpreadsheetML parsing.

Rendering runs one disposable native process at a time, coalesces requests for identical revisions, and cancels abandoned jobs. Limits are 32 MiB input, 32 MiB per decompressed ZIP entry, 128 MiB total decompression, 128 MiB PDF output, a 4 GiB process address space, and 60 seconds per conversion. Up to four jobs may be active or queued. The versioned disk cache under TEMP_STORAGE_PATH (or the OS temporary directory) is bounded to 256 MiB of PDFs. File identity, size, modification time, and change time invalidate cached previews.

The preview binary enables Linux Landlock before parsing any Office content, closes inherited descriptors other than standard I/O, and disables process dumping. Only the copied input, bundled font configuration/fonts, and a private job scratch directory are readable; only scratch is writable. Execution of other programs is denied. The server passes a minimal environment and keeps temporary files and font caches inside scratch. There is no extra sandbox executable or runtime dependency.

Landlock ABI 3 or newer must be enabled (upstream Linux 6.2+); unsupported hosts fail closed. Additional restrictions follow the available ABI: TCP at 4, abstract Unix sockets and signals outside the sandbox at 6, pathname Unix sockets at 9, and UDP at 10. Older ABIs emit a diagnostic about reduced coverage. Landlock does not restrict all metadata operations, including stat and chmod. This supplements Sandstorm's grain isolation, rather than fully isolating every same-grain operation. Tested with Sandstorm's default seccomp policy; its experimental policy blocks Landlock and previews will fail closed there. See the kernel Landlock documentation.

Converter and sandbox regression tests live in the davros-preview project. Davros's server tests exercise the downloaded release through the preview API.

For server tests, install Poppler (poppler-utils on Debian) for PDF text validation, and run yarn fetch:native-preview before yarn test:server. Development can set DAVROS_PREVIEW_NATIVE_DIR to an existing build directory.

Sandstorm Development

A few parts of Davros are dependent on running within Sandstorm, such as the authentication instructions on the Clients page. To run inside Sandstorm, first get vagrant-spk. Then, within the Davros directory, run

vagrant-spk vm up vagrant-spk dev

While this works it requires that you re-run vagrant-spk dev manually anytime you make a change. To have this done automatically consider using ember-cli-vagrant-spk instead which will monitor your filesystem for changes and restart the server for you.

Linting

• yarn lint:hbs
• yarn lint:js
• yarn lint:js -- --fix

Releasing

Releasing an app is a little bit convoluted. This assumes you are on a non-linux machine, running sandstorm via vagrant-spk. On linux, you might be able to get away with skipping step 1.

1. Edit .sandstorm/sandstorm-pkgdef.capnp and update appVersion and appMarketingVersion. Bump major version for major breaking changes, minor version for significant new features, and patch version for tiny features and bugfixes.
2. Edit CHANGELOG.md and add a section with your new version.
3. Run yarn build to build the UI.
4. Run vagrant-spk dev and navigate around the app testing various functionality. This is generally good to do, but when you exit, this will also update .sandstorm/sandstorm-files.list with any new files.
5. Run vagrant-spk pack build/[VERSION].spk (replacing [VERSION] with the version you chose in step 2)
6. On a sandstorm instance, upload the packed app file and install it. Test it to ensure everything works properly and that all files were included.
7. Commit any uncommitted changes and tag them v[VERSION].
8. Run vagrant-spk publish build/[VERSION].spk

Acknowledgements

• Built on Ember.js.
• WebDAV support built with jsDAV.

License

See LICENSE file.