Mölla

This is the reference implementation of the Kvarn server library, offering a simple config to get you started using Kvarn.

See moella --help for config options

It's e.g. currently used by my domains icelk.dev and kvarn.org.

See kvarn.org for an example config and the schema of the config. You can also take a look at the icelk.dev config for a production example.

Usage

First install moella.

Next, create a config file, let's say host.ron:

(
    hosts: [
        Plain (
            name: "my-website.com",
            pk: "pk.pem",
            cert: "cert.pem",
            auto_cert: true,
            path: "./",
            extensions: ["arbetrary-name"],
            options: (
                public_data_directory: "build",
                disable_server_cache: true,
                disable_client_cache: false,
            )
        ),
    ],
    extensions: {
        "arbetrary-name": [
            // most of this can be removed; it's just an example
            Csp ({
                "/*": FromDefault ({
                    script_src: [ UnsafeInline, WasmUnsafeEval ],
                    style_src: [
                        Uri("https://fonts.googleapis.com"),
                        Uri("https://fonts.googleapis.com"),
                        UnsafeInline,
                    ],
                    default_src: [ Uri("https://fonts.gstatic.com") ],
                    img_src: [ Uri("*"), Scheme("data:") ]
                }),
                // SVG XSS attacks if viewing file
                "/groups/logo-images/*": FromDefault ({}),

            }),
            ClientCache ({
                "/": MaxAge(3600),
                "/_app/immutable/": Full,
                "/groups/logo-images/": Changing,
                "/groups/data": Changing,
                "/groups/locations": Changing,
            }),
        ]
    },
    import: ["./some-other.config-file.ron"],
    ports: Standard(All),
)

Now, run moella -c host.ron --dev. Your website should be working. Remove the --dev flag when deploying.

Link to a systemd service template

See kvarn.org for more details.

Installation

If you have cargo installed, simply run cargo install moella.

There are builds available for Linux in Github Actions, and for other platforms under Releases.

To run it, download the binary appropriate for your platform.

• Platform specifics:
  • If you run Linux: run chmod +x <downloaded binary> to make it executable.
  • If you run macOS: run chmod +x <downloaded binary>, then open Finder and find the binary. Right click and click Open. Accept the warning.
  • On Windows, it should just run
• Lastly, run the command ./<downloaded binary> --help in your shell to get usage information.

Build from latest source

Install Rust and then run the following:

**If you're on macOS or Windows, you need to add --no-default-features -F bin.

$ cargo install moella

Documentation

• Kvarn website
• Library docs

Development

During development, Mölla requires Kvarn to be cloned at ../kvarn, Kvarn Search at ../kvarn-search, and Kvarn Auth at ../kvarn-auth.

Changelog

v0.2.0

Many bugfixes to reverse proxy, including websockets finally working and body streaming for large files (e.g. movies through Jellyfin). Zstd is also supported now, and compression levels are generally more fitting.

Added

• Zstd compression
• Reverse proxy body streaming for large files
• You can now use e.g. http://10.0.0.12:8096 as an option to the reverse proxy. Previously "tcp" was the only option.
• Option to make systemd services work with a bug in io_uring (kvarnctl)
  • Sometimes a double-free happens after Kvarn has finished. This can be ignored, and so a flag to ignore that was added to kvarnctl

Improved

• Faster HTTP/3
• Dynamic compress based on if the response is cached or not.
• Make io_uring even faster with less allocations
• Performance related to HTTP/1 requests and responses. Also useful for other HTTP versions when reverse proxy is used (HTTP/1 is used for reverse proxy).
• Updated dependencies

Fixed

• Caching issues for reverse proxy
• Reverse proxy websockets.
• Reverse proxy for Jellyfin
• Auto cert made more robust
• Auto cert in development behaves better
• Auto cert private key having permission 644 instead of 600
• kvarn_signal (used by kvarnctl) fixed commands sometimes not being sent