dev106

Dev106

6.106 development containers and configuration for neovim users.

Features:

1. dev106 automatically detects your git repository root. You can invoke a shell from anywhere inside your repo and it will seek the repository root.
2. Telerun configuration gets synced with the host. Run authorize-telerun in any dev106 shell, and then never again.
3. UID/GID preservation; when you exec into a dev106 container, you are a dev106 user, but with the same uid and gid as on your host machine. No permission hiccups. sudo works automatically (provided you have a good image).

$ cd {some_6106_assignment}
# pull the image first
$ dev106 pull
# this will give you a shell into a running container. authorize-telerun will
# save your telerun credentials and have it persist across containers.
$ dev106
dev106@64bf911d7f23:/workspace$ authorize-telerun
Enter your telerun credentials
Username: ^C
dev106@64bf911d7f23:/workspace$
logout

# this will kill the container
$ dev106 kill
# this will attempt to kill and restart a container.
$ dev106 restart
dev106@64bf911d7f23:/workspace$
logout

Installation

I'll hopefully get precompiled binaries up and running, but for now, just do

go install github.com/junikimm717/dev106@latest
# run the binary, this should work if ~/go/bin is in your $PATH
dev106

If that program runs successfully, it should have generated a config at ~/.config/dev106/config.toml (on your host machine).

Go to ~/.config/dev106/config.toml and change the name of the docker image to your image (by default it uses Juni's neovim image).

Container Bootstrapper

Important: The home directory of the dev106 user is hard coded to be /home/dev106. This is important to note when you create docker images, as you should think from the perspective of the dev106 user, not the root user.

There is a container entrypoint in ./cmd/bootstrap (in this source code tree) that works to set the UID and GID of the running docker process to match your machine. It accepts the following environment variables:

• DEV_UID - your UID on your host machine. Must be a nonnegative integer.
• DEV_GID - your GID on your host machine. Must be a nonnegative integer.

Environment variables configured by the Dockerfile authors:

• DEV_CHOWN - a colon-separated list of directories to run a recursive chown on (e.g. /nvim:/dir/dir2); the image authors should be responsible for this.
• DEV_CHOWNEXCLUDE - a colon separated list of directories to exclude from chowning when doing the recursive chown operation. You should use this on massive artifact directories that don't actually need to be written to.

In short, here is the flow of what happens when you launch a dev106 container:

1. The CLI launches a dev106 container.
2. The bootstrapper uses the env vars above to rewrite the owner UID and GID's on the container filesystem
3. The CLI starts a shell into the dev106 container with the same UID and GID as the user.

Image Sample

Please reference this image when creating your own docker images.

I'll hopefully create a github repo soon with a sample Dockerfile and GitHub actions configuration.

# this image already has the entire 6.106 toolchain installed.
FROM ghcr.io/junikimm717/dev106/mit_6106:latest

# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
# Neovim Installation and Configuration

RUN mkdir -p /home/dev106/.config/nvim && \
  curl -L https://github.com/junikimm717/nvim2025/archive/master.tar.gz\
  | tar -xz --strip-components=1 -C /home/dev106/.config/nvim
# this is a custom runtime configuration file for juni's neovim setup, ignore
# for your own config.
RUN <<EOF cat > /home/dev106/.config/nvim/lua/configs/init.lua
---@type Config
return {
  mason = {},
  lazy = require("themes.kanagawa"),
  treesitter = { "c", "make", "bash", "asm" }
}
EOF
RUN cd /home/dev106/.config/nvim && make -j$(nproc)
RUN /home/dev106/.config/nvim/build/bin/setup-nvim
# <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
# Home Directory Configuration

# you almost certainly want opencilk's bin directory first (so that you have
# access to their clangd lsp)
RUN <<EOF cat > /home/dev106/.profile
# I like using vim mode
set -o vi
export PATH=/opt/6106/opencilk/bin:$PATH
export PATH=/nvim/build/bin:$PATH
EOF
# <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
# Env Var Configuration

# Values for the two environment variables below are formatted as
# /my/dir/1:/my/dir2:... (colon-separated)

# if you have directories outside of /home/dev106 that need to be chowned to be
# owned by dev106 at runtime, do that here.
ENV DEV_CHOWN=""

# There is no need to chown these packages, and they take up significant
# overhead on runtime startup
ENV DEV_CHOWNEXCLUDE="/home/dev106/.config/nvim/build/pkgs"
# <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

# We recommend you keep this option as-is.
WORKDIR /workspace