waynr/dfiles

Composable container application manager tool.

dfiles

dfiles is primarily two things:

• a collection of containerized desktop/GUI applications intended for Linux desktops
• a library designed to facilitate the quick development of new containerized desktop/GUI applications by abstracting away concerns such as providing container access to host services like pulseaudio, dbus, X11

About

Running your desktop application in a container has a number of benefits:

• Applications are isolated from one another as much as possible at the process level.
• You get to choose what parts of your filesystem are "seen" by each application.
• Many applications assume only you only ever want to use it in a single context (login, session state, project data, etc). With dfiles-managed applications you get the opportunity to specify differente runtime profiles using the -p/--profile flag to effectively isolate different use cases from one another.
• Containerized applications are highly portable between not only Linux distributions, but between different computers and across reinstalls; thanks to Cargo (rust's package manager), installing dfiles-based apps is trivially easy on new computers and (on the roadmap) will eventually allow you to choose the version of the app installed.
• Some people don't like installing proprietary libraries and applications onto their main operating system but some use case (Steam, Skype, Zoom, etc) require it; containerization lets them limit those applications' access to the rest of the system.

However, there can be some drawbacks:

• Since each application runs in its own Linux container/namespace with its own distinct filesystem, there will be reduced memory efficiencies from the use of shared/dynamically-linked libraries.

The target audience, at least during early stages of development, are technically savvy people who don't mind a few rough edges here and there while I (and anyone who wants to contribute) work to smooth them out.

Building & Installing

dfiles currently assumes that you have a reasonably up-to-date Rust toolchain and package manager installed. The rust-lang book installation guide is the best source of information on how to get Rust up and running.

Usage

Installing dfiles apps

Build a dfiles app

Assuming you have not cargo install'd the app directly from crates.io and assuming that your cargo bin directory is at the front of your PATH:

git clone git@github.com:waynr/dfiles
cd dfiles
cargo install -p firefox
firefox build

You should see the same output as you would see building a docker image using docker build ..

TODO: Install from crates.io

Run a dfiles app

After installing an app and building its associated container image:

firefox run

This will run firefox in the "default" profile. This is not to be confused with the built-in firefox concept of profiles but relates instead to the host system directories mounted into the container at run time. To mount a different set of profile directories, which in the case of firefox results in total isolation of session data, plugins, browse history, etc:

firefox run -p a-different-profile

For firefox and other applications with a built-in notion of profiles it may not make as much sense to do this, but for other applications where there is one assumed set of profile/session data for a given user, you may get more use out of this.

Configure a dfiles app

In addition to default behaviors built into applications it is possible to configure them the application level with customizations such as volume mounts, cpu/memory limits, etc:

firefox config --mount <hostpath>:<containerpath>
firefox config --memory 1024mb

Configuration specified in this way will apply to all of the application's profiles. To limit config settings to a specific profile:

firefox config --profile --mount <hostpath>:<containerpath>

Roadmap

• Before open source:
  • Aspect-oriented configuration schema for applications with support for profiles.
  • Implement configurable aspects:
    • CPU shares
    • Memory
    • Network mode
    • Locale
    • CurrentUser
      • Replace buildtime user setup with entrypoint script user setup.
  • Improve README.
  • Implement some kind of automated image build and push.
  • Replace all unwrap and Box<dyn Error> instances with better error handling
  • Figure out some kind of data directory approach that isolates dfiles application data directories to some kind of dfiles-specific XDG data directory. For example, don't let firefox use $HOME/.mozilla/firefox -- dfiles apps should not mess with application data managed by vanilla installs of the same app
  • Figure out container versioning schema of some kind.
  • Prune current apps of unnecessary aspects (most probably don't need SysAdmin or Shm)
• Remove NetworkHost default behavior.
• Consider framework for lightweight runtime container setup:
  • generate and inject entrypoint script at runtime
    • simple, easy to understand
    • but could burn through seconds every program startup
  • build user-specific image from prebuilt static base image with user-specific, config-dependent dynamic setup steps

Similar Projects

jessfraz/dockerfiles

dfiles is strongly influenced by github.com/jessfraz/dockerfiles and this blog post.

Significant differences include:

• dfiles generates Dockerfiles dynamically based on a combination of hard-coded and user-configured "Aspects"
  • makes it easy to share code between different applications
• dfiles hides implementation details of running containers by generating docker run command lines

snap

Snap is a distro-agnostic package manager that distributes containerized applications, similar in principle to the end result produce by dfiles but more well-fleshed out and probably more suitable if all you care about is just installing a thing and getting it running.

Significant differences include:

• dfiles targets Docker as its container runtime and aims to (eventually) leverage the docker registry ecosystem for distribution of images
• dfiles is more developer-oriented for people who like to build their own images