Apple Containers

Apple container runs OCI containers inside lightweight VMs on macOS (hypervisor isolation, not just namespaces). Used for local dev environments with full Linux, SSH access via Tailscale, and Zed remote development.

Prerequisites

• macOS 26+ (Tahoe) on Apple silicon
• container CLI installed (via install.sh --apps)
• Daemon running: container system start
• A Tailscale auth key (from 1Password or provided by user)

Creating a Dev Container

Follow these steps in order. Do not skip any step.

1. Create and start the container

container run --name <name> -d --cpus 4 --memory 8G ubuntu:25.04 sleep infinity

Naming convention: ivs-<purpose> (e.g., ivs-klundstedt-ac, ivs-demo-ac).

2. Install base packages and create user

container exec <name> bash -c "
    apt-get update -qq && apt-get install -y -qq git curl sudo zsh >/dev/null 2>&1
    useradd -m -s /bin/zsh klundstedt
    echo 'klundstedt ALL=(ALL) NOPASSWD:ALL' > /etc/sudoers.d/klundstedt
    chmod 440 /etc/sudoers.d/klundstedt
"

Passwordless sudo is required — install.sh uses sudo for apt, chsh, systemctl, and tailscale commands. Without NOPASSWD, it hangs waiting for a password with no TTY.

3. Install Tailscale and dotfiles

Tailscale is required — it provides the stable hostname for SSH, Zed remote dev, and SSH agent forwarding from the Mac's 1Password agent.

Start tailscaled as a detached process first — do NOT use & inside container exec (it creates zombies). Use container exec -d instead:

container exec -d <name> bash -c "curl -fsSL https://tailscale.com/install.sh | sh && tailscaled --tun=userspace-networking"
sleep 3

Resolve the auth key and bring Tailscale up:

TS_AUTHKEY="$(op read 'op://Employee/Tailscale - iv-internal-dev/credential' --account industryvault.1password.com)"
container exec -e "TS_AUTHKEY=$TS_AUTHKEY" <name> tailscale up --authkey "$TS_AUTHKEY" --hostname <name> --ssh

Verify SSH connectivity from the host:

ssh -o StrictHostKeyChecking=accept-new <name> echo ok

Do not proceed until this succeeds.

Now install dotfiles via Tailscale SSH so the Mac's 1Password agent is forwarded. This gives install.sh access to GitHub over SSH and enables git commit signing automatically on first login:

ssh <name> -l klundstedt "curl -fsSL https://raw.githubusercontent.com/kylelundstedt/dotfiles/master/install.sh | bash"

Do not skip this step — without it, Zed's Claude agent will fail with "Query closed before response received."

4. Clone project repos

The Mac's SSH config forwards the 1Password agent to *.ts.net hosts (ForwardAgent yes). This means ssh <name> gives the container access to your GitHub SSH keys — no tokens needed. install.sh configures GitHub SSH over port 443 on Linux (port 22 is blocked on Apple Containers). Clone directly:

ssh <name> -l klundstedt git clone git@github.com:<org>/<repo>.git /home/klundstedt/<repo>

Git commit signing is automatically enabled on first login via Tailscale SSH (the shell detects the forwarded agent).

5. Connect from Zed

Open the project in Zed via CLI using the Tailscale hostname:

zed ssh://klundstedt@<name>/home/klundstedt/<repo>

Do not add ssh_connections to zed/settings.json — those are ephemeral VM references that don't belong in the dotfiles repo.

CLI Quick Reference

container list                          # List containers
container exec <name> <cmd>             # Run command in container
container exec -u klundstedt <name> <cmd>  # Run as klundstedt
container exec -d <name> <cmd>          # Run detached (for daemons)
container exec -e KEY=VAL <name> <cmd>  # Pass env var
container stop <name>                   # Stop container
container start <name>                  # Start stopped container
container rm <name>                     # Delete container
container inspect <name>                # Show container details
container logs <name>                   # View container logs

File Transfer

# Host to container (pipe via stdin)
cat local-file.txt | container exec -i <name> bash -c "cat > /path/in/container"

# Tar a directory in
tar -cf - -C /local/dir . | container exec -i <name> bash -c "tar -xf - -C /dest"

# Container to host
container exec <name> cat /path/in/container > local-file.txt

Troubleshooting

• Container won't start: Run container system start to ensure the daemon is running.
• SSH fails after Tailscale: Check tailscale status inside the container. Verify the hostname matches.
• install.sh fails: Check that git and curl are installed (step 2). Run with bash -x install.sh for debug output.
• Zed agent error "Query closed before response received": Claude Code isn't installed on the container. Run install.sh on the container.
• Zombie processes from tailscaled &: Never background processes with & inside container exec. Use container exec -d for persistent daemons.