Editor support

Every sandbox is reachable over SSH under a host name ending in .fbk. Editors with remote development over SSH can open the workspace in the sandbox, so the editor’s language servers, terminals and agents run in the sandbox instead of on your host.

SSH host names

fbkd generates an SSH key pair and an SSH config in ~/.local/share/firebrick/ssh (or $XDG_DATA_HOME/firebrick/ssh), and adds an Include line for that config to the top of ~/.ssh/config. It rewrites the generated config whenever sandboxes are added or removed; don’t edit it, because your changes are overwritten.

Each sandbox gets a host name after its project directory: the directory’s name in lowercase, with every run of other characters than letters and digits replaced by -, followed by .fbk. A project in ~/projects/My.App gets my-app.fbk. When two projects share a directory name, the second gets my-app-2.fbk, the third my-app-3.fbk, and so on. fbk ls lists the host name of each sandbox.

ssh my-app.fbk

The host entries log in as the agent user with Firebrick’s own key and known_hosts file, and run fbk ssh-proxy as their ProxyCommand. That hidden command tunnels the connection through the daemon’s socket to the SSH server in the sandbox, so no SSH port is published on your host. Connecting to a stopped sandbox starts it.

The sandbox’s SSH server doesn’t support agent forwarding (ssh -A), so your SSH keys stay on the host. Use git over HTTPS with a secret instead; see Git over HTTPS.

VS Code, VS Code Insiders, Cursor and VSCodium

These editors connect with the Remote - SSH extension, which reads the hosts from ~/.ssh/config. Remote - SSH asks for the platform of each new host, so fbkd maps every .fbk host to linux in the remote.SSH.remotePlatform setting of each of these editors that’s installed. It edits the editor’s user settings.json and leaves your other settings, comments and formatting as they are:

Platform	Settings file
Linux	~/.config/<editor>/User/settings.json
macOS	~/Library/Application Support/<editor>/User/settings.json

<editor> is Code, Code - Insiders, Cursor or VSCodium. On Linux, $XDG_CONFIG_HOME replaces ~/.config when it’s set. fbkd skips an editor whose User directory doesn’t exist.

fbk start prints a command that opens the workspace in the sandbox:

$ fbk start
Connect with: ssh my-app.fbk
Open in VS Code: code --folder-uri vscode-remote://ssh-remote+my-app.fbk/workspaces/my-app
Open in Zed: zed ssh://my-app.fbk/workspaces/my-app

Run the printed code command, or pick the host in Remote - SSH and open /workspaces/my-app. For Cursor, VS Code Insiders or VSCodium, replace code with cursor, code-insiders or codium.

Zed

Zed’s remote development uses the system ssh, so the .fbk hosts work as they are. fbkd adds one entry per sandbox, with its workspace as the project, to ssh_connections in Zed’s settings.json, so you can pick the sandbox in Zed’s Remote Projects dialog. It owns the entries whose host ends in .fbk and leaves the rest of the file as you wrote it.

Zed’s settings live in ~/.config/zed/settings.json; on Linux, $XDG_CONFIG_HOME replaces ~/.config when it’s set. fbkd does nothing when the zed directory doesn’t exist.

Run the zed command that fbk start prints:

zed ssh://my-app.fbk/workspaces/my-app

JetBrains IDEs

JetBrains Gateway and the Remote Development feature of IntelliJ IDEA, PyCharm and the other JetBrains IDEs connect over SSH, but Firebrick doesn’t configure them. Set up the connection by hand:

1. Start the sandbox with fbk start.
2. In Gateway, or under File | Remote Development in the IDE, choose SSH and create a connection to the host my-app.fbk. Use your SSH config (OpenSSH config and authentication agent), so the connection goes through the ProxyCommand that fbk sets up; the user is agent.
3. Pick the IDE to install in the sandbox, and open the project at /workspaces/my-app.

The IDE backend runs in the sandbox, so give the sandbox enough memory in resources.memory; see Configuration.