Installing nerdctl (contaiNERD CTL) and BuildKit

A Docker-compatible CLI for Containerd

More to come—such as using eStargz—but for now see below. Create a file with the contents below, then simply execute it:

#!/usr/bin/env bash

# Credits to: https://www.guide2wsl.com/nerdctl/
setup_nerdctl() {
  mkdir /tmp/nerdctl || true
  cd /tmp/nerdctl

  set -x

  ARCHITECTURE="$([ "$(uname -m)" = "x86_64" ] && echo "amd64" || echo "arm64")"

  VERSION_NERDCTL_OFFICIAL="$(curl --silent 'https://api.github.com/repos/containerd/nerdctl/releases/latest' | jq '.tag_name')"
  VERSION_NERDCTL="${VERSION_NERDCTL_OFFICIAL//v/}"
  VERSION_CNI="$(curl --silent 'https://api.github.com/repos/containernetworking/plugins/releases/latest' | jq '.tag_name')"
  VERSION_BUILDKIT="$(curl --silent 'https://api.github.com/repos/moby/buildkit/releases/latest' | jq '.tag_name')"

  wget "https://github.com/containerd/nerdctl/releases/download/v${VERSION_NERDCTL}/nerdctl-${VERSION_NERDCTL}-linux-${ARCHITECTURE}.tar.gz"
  tar -zxf nerdctl-${VERSION_NERDCTL}-linux-${ARCHITECTURE}.tar.gz nerdctl
  sudo mv nerdctl /usr/bin/nerdctl
  rm nerdctl-${VERSION_NERDCTL}-linux-${ARCHITECTURE}.tar.gz

  wget "https://github.com/containernetworking/plugins/releases/download/${VERSION_CNI}/cni-plugins-linux-${ARCHITECTURE}-${VERSION_CNI}.tgz"
  sudo mkdir -p /opt/cni/bin/
  sudo tar -zxf cni-plugins-linux-${ARCHITECTURE}-${VERSION_CNI}.tgz -C /opt/cni/bin/
  rm cni-plugins-linux-${ARCHITECTURE}-${VERSION_CNI}.tgz

  # https://github.com/moby/buildkit for building images
  wget "https://github.com/moby/buildkit/releases/download/${VERSION_BUILDKIT}/buildkit-${VERSION_BUILDKIT}.linux-${ARCHITECTURE}.tar.gz"
  tar -zxvf buildkit-${VERSION_BUILDKIT}.linux-${ARCHITECTURE}.tar.gz
  sudo mv bin/* /usr/bin/
  rm buildkit-${VERSION_BUILDKIT}.linux-${ARCHITECTURE}.tar.gz

  chmod 700 ${HOME}/bin
  cp "$(which nerdctl)" ${HOME}/bin
  sudo chown root ${HOME}/bin/nerdctl
  sudo chmod +s ${HOME}/bin/nerdctl

  mkdir -pv ~/.local/bin || true
  ln -sv "$(which nerdctl)" ~/.local/bin/docker
  ln -sv "$(which nerdctl)" ~/bin/docker
  ln -sv "$(which nerdctl)" ~/.bin/docker

  sudo apt install containerd
  # sudo chgrp "$(id -gn)" /run/containerd/containerd.sock

  wget https://raw.githubusercontent.com/containerd/nerdctl/main/extras/rootless/containerd-rootless-setuptool.sh
  wget https://raw.githubusercontent.com/containerd/nerdctl/main/extras/rootless/containerd-rootless.sh
  chmod +x containerd-rootless-setuptool.sh
  chmod +x containerd-rootless.sh
  PATH="$(pwd):${PATH}" ./containerd-rootless-setuptool.sh
  systemctl --user enable containerd.service
  systemctl --user start containerd.service

  sudo loginctl enable-linger "$(whoami)"

  # systemd-analyze --system unit-paths
  # mkdir -pv ~/.local/share/systemd/user || true
  # cd ~/.local/share/systemd/user
  mkdir -pv ~/.config/systemd/user.control || true
  cd ~/.config/systemd/user.control

  wget https://raw.githubusercontent.com/moby/buildkit/master/examples/systemd/user/buildkit-proxy.service
  wget https://raw.githubusercontent.com/moby/buildkit/master/examples/systemd/user/buildkit-proxy.socket
  wget https://raw.githubusercontent.com/moby/buildkit/master/examples/systemd/user/buildkit.service

  systemctl --user daemon-reload
  systemctl enable --user --now buildkit-proxy.service
  systemctl enable --user --now buildkit-proxy.socket
  systemctl enable --user --now buildkit.service
  systemctl start --user --now buildkit-proxy.service
  systemctl start --user --now buildkit.service

  # systemd-analyze --global unit-paths
  # Probably /usr/lib/systemd/system
  sudo mkdir -pv /usr/lib/systemd/system
  cd /usr/lib/systemd/system
  sudo wget https://raw.githubusercontent.com/moby/buildkit/master/examples/systemd/system/buildkit.service
  sudo wget https://raw.githubusercontent.com/moby/buildkit/master/examples/systemd/system/buildkit.socket

  sudo systemctl daemon-reload
}
setup_nerdctl