Devcontainer setup¶

VS Code features don't work with Podman

In VS Code, I had to abandon working with VS Code features, such as adding Zsh or ChezMoi to my devcontainer.

In a cryptic summary: these features need a BuildKit way of creating container images, and this is not yet compatible with Podman.

As a result, I had to change some of my devcontainer setups, switching to a more classical ContainerFile setup.

In my VS Code user settings, I have added my GitHub dotfiles repository, and that contains an install script with the software I want in my container.

settings.json

{
    "dotfiles.repository": "rolfkleef/dotfiles",
    "dotfiles.installCommand": "./install.sh",
    "dotfiles.targetPath": "~/.local/share/chezmoi",
}

With VS Code's support for a dotfiles repository in my user settings, I then use the install script in my dotfiles repository to add for instance Zsh and OhMyZsh to the container.

install.sh

#!/bin/sh

# -e: exit on error
# -u: exit on unset variables
set -eu

# 1. Upgrade packages (for Debian/Ubuntu-based images)
export DEBIAN_FRONTEND=noninteractive
apt-get update && apt-get upgrade -y

# 2. Install helpers
apt-get install -y zsh curl git nano

# 3. Install Oh My Zsh
if [ ! -d "$HOME/.oh-my-zsh" ]; then
  sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)" "" --unattended
fi

# 4. Set Zsh as the default shell for the container user
chsh -s $(which zsh) "$(whoami)"

# 5. Install and init chezmoi
sh -c "$(curl -fsLS get.chezmoi.io)" -- -b /usr/local/bin
chezmoi init --apply

I do have to run zsh by hand the first time a fresh container starts.

My conventions¶

At the moment, all my devcontainer setups are Debian/Ubuntu-based, so the install script above works everywhere.
I always use a bind mount to make my host directory available inside my container, and always in the directory /workspace. In both Docker Desktop and Podman, the user root within the container is mapped to the local user on the host system, and file permissions should work ok.
It also allows me to configure Zsh in my dotfiles to store its history in /workspace/.zsh_history, so it is stored in the host directory, to have a persistent shell history across container rebuilds.
The host directory typically contains a .env file. At a minimum, I specify a Compose project name. When additional services like a database are included, this is a good place to include usernames and passwords for that.
The default timezone in a container is usually set to UTC. I therefore add my own timezone to the .env file, so that timestamps on files are shown the same as on my host system.
.env
```
COMPOSE_PROJECT_NAME=drostan-notes
TZ=Europe/Amsterdam
```
and that file is added to the service for the devcontainer:
compose.yml
```
services:
  mkdocs:
    image: python:3.12
    command: sleep infinity
    volumes:
      - ..:/workspace
    env_file:
      - ../.env
```

Tip

To let a container also reach other services via localhost, add the following to its definition in compose.yml:

extra_hosts:

- localhost:host-gateway

Of course, this requires them to run on unique ports.