Helix devcontainer

devcontainer.sh

#!/usr/bin/env bash

set -e

remove_flag=""
if [ "$1" = "true" ]; then
    remove_flag="--remove-existing-container"
fi

# Generate certificate
path=tmp/devcontainers
mkdir -p $path && pushd $path
ssh_key=$(cat /dev/urandom | tr -dc '[:alpha:]' | fold -w ${1:-20} | head -n 1)
ssh-keygen -q -N '' -t rsa -f $ssh_key
popd

# Start container
devcontainer up $remove_flag \
    --mount "type=bind,source=$HOME/.config/helix,target=/home/archlinux/.config/helix" \
    --mount "type=bind,source=$HOME/.wakatime.cfg,target=/home/archlinux/.wakatime.cfg" \
    --workspace-folder .

script="
# Copy generated keys
mkdir -p \$HOME/.ssh
cat \$PWD/$path/$ssh_key.pub > \$HOME/.ssh/authorized_keys
chmod 644 \$HOME/.ssh/authorized_keys
chmod 700 \$HOME/.ssh
"

# Add pub key to SSH allow list
devcontainer exec --workspace-folder . sh -c "$script"
devcontainer exec --workspace-folder . sudo /usr/local/share/ssh-init.sh

name=$(devcontainer read-configuration --workspace-folder . | jq -r '.configuration.name')
container_name="${name}_devcontainer-app-1" # you might also need to change this if `devcontainer-cli` creates a differently named container
ip_addr=$(docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' $container_name)

PORT=${PORT:-2222}

# Create a `known_hosts` file that will be used by only this project
ssh-keyscan -t ssh-rsa -p $PORT $ip_addr >> tmp/known_hosts

# Connect directly via IP address instead of localhost
ssh -t -i $PWD/$path/$ssh_key \
    -o UserKnownHostsFile=tmp/known_hosts \
    -o NoHostAuthenticationForLocalhost=yes \
    -o UserKnownHostsFile=/dev/null \
    -o GlobalKnownHostsFile=/dev/null \
    -p $PORT "archlinux@$ip_addr" \
    "cd /workspaces/${PWD##*/}; fish --login" # you might need to change this according to the shell inside the image

First you must enable your devcontainer to have SSH. You can use this devcontainer.json. To have the devcontainer have a running ssh daemon, you can use this reference.

Put the below script on your $PATH, make it executable and run it in your project folder. You will be dropped into the terminal of your devcontainer from where you can run helix . to start up helix.

So via your solution, run my container and just connect via ssh into it?
How should I use your script correctly?

Just cd into the project with has the .devcontainer folder in it. Then you can run this script (I have it saved as ~/.local/bin/devcontainers.sh. After this, you will be dropped into the shell of the container. There you can run hx . and continue editing as you would in helix.

This is interesting. So, from an existing project to get helix inside a devcontainer running, I have to do the followig:

1. Create a .devcontainer folder with at least a devcontainer.json inside
2. Run the script above

Did you work with devcontainer in vscode too? How is this different from this approach?

Thanks!

The basic idea is that you should have a running ssh daemon inside your devcontainer to connect to. The links I have provided above lead to my specific devcontainer configuration that do that. Of course you're free to devise your own configuration.

Yes i have worked extensively with vscode devcontainers. Devcontainers in vscode work on almost the same premise, but instead of connecting to an ssh daemon, they connect to a vscode-server (which gets installed once the devcontainer is created the first time) and work via a client server model (AFAIK).

Am I understanding this correctly that I'd be using helix from the container instead of locally?
If so, how's responsiveness (and a bit about your network performance metrics)?

It's been a long time since I last used this, but i don't remember having any problems about responsiveness. The connection is made over localhost and ssh is quite fast :)