setup-nix-docker.sh

#!/bin/sh

set -e

echo "This script will:"
echo ""
echo "- retrieve and start lnl7/nix-docker container"
echo "- modify ~/.ssh/config ~root/.ssh/config /etc/nix/machines /etc/nix/nix.conf"
echo "- restart nix daemon"
echo "- test the remote builder"
echo ""
echo "Press Ctrl-C to cancel, any other key to continue."

read


SSH_KEY_FILE=$(mktemp)
SSH_ROOT_CONFIG=$(mktemp)
SSH_USER_CONFIG=$(mktemp)
NIX_MACHINES_CONFIG=$(mktemp)
NIX_CONFIG=$(mktemp)

cat >> $SSH_ROOT_CONFIG <<EOF
Host nix-docker
  User root
  HostName 127.0.0.1
  Port 3022
  IdentityFile /etc/nix/docker_rsa
EOF

cat >> $SSH_USER_CONFIG <<EOF
Host nix-docker
  User root
  HostName 127.0.0.1
  Port 3022
  IdentityFile ~/.ssh/docker_rsa
EOF

cat >> $NIX_MACHINES_CONFIG <<EOF
nix-docker x86_64-linux /etc/nix/docker_rsa 4 1
EOF

cat >> $NIX_CONFIG <<EOF
builders = @/etc/nix/machines
EOF

# -----------------------------------------------
echo "-- retrieving the nix-docker ssh key ..."
# -----------------------------------------------

curl --silent https://raw.githubusercontent.com/LnL7/nix-docker/master/ssh/insecure_rsa > $SSH_KEY_FILE
chmod 600 $SSH_KEY_FILE
echo "-- copying ssh key to /etc/nix/docker_rsa (requires sudo) ..."
sudo cp $SSH_KEY_FILE /etc/nix/docker_rsa
echo "-- copying ssh key to ~/.ssh/ ..."
cp $SSH_KEY_FILE ~/.ssh/docker_rsa

# -----------------------------------------------
echo "-- adding ssh config to ~/.ssh/config ..."
# -----------------------------------------------

mkdir -p ~/.ssh/

if ! grep -q "nix-docker" ~/.ssh/config ; then
  cat $SSH_USER_CONFIG >> ~/.ssh/config
fi

# -----------------------------------------------
echo "-- adding ssh config to /var/root/.ssh/config ..."
# -----------------------------------------------

sudo mkdir -p /var/root/.ssh
sudo touch /var/root/.ssh/config

if ! sudo sh -c "grep -q 'nix-docker' /var/root/.ssh/config" ; then
  sudo sh -c "cat $SSH_ROOT_CONFIG >> /var/root/.ssh/config"
fi

# -----------------------------------------------
echo "-- adding remote builder to nix config ..."
# -----------------------------------------------

sudo touch /etc/nix/machines
if ! grep -q "nix-docker" /etc/nix/machines ; then
  sudo sh -c "cat $NIX_MACHINES_CONFIG >> /etc/nix/machines"
fi

# -----------------------------------------------
echo "-- configuring remote builders ..."
# -----------------------------------------------

if ! grep -q "builders = @/etc/nix/machines" /etc/nix/nix.conf ; then
  sudo sh -c "cat $NIX_CONFIG >> /etc/nix/nix.conf"
fi

# -----------------------------------------------
echo "-- restarting nix daemon ..."
# -----------------------------------------------

sudo launchctl unload /Library/LaunchDaemons/org.nixos.nix-daemon.plist
sudo launchctl load /Library/LaunchDaemons/org.nixos.nix-daemon.plist

# -----------------------------------------------
echo "-- starting lnl7/nix-docker container ..."
# -----------------------------------------------

if ! docker ps | grep "nix-docker" >/dev/null ; then
  docker run --restart always --name nix-docker -d -p 3022:22 lnl7/nix:ssh
fi

# -----------------------------------------------
echo "-- testing ssh connection ..."
# -----------------------------------------------

ssh nix-docker -C uname
sudo sh -c "ssh nix-docker -C uname"

# -----------------------------------------------
echo "-- testing builder ..."
# -----------------------------------------------

nix build '(with import <nixpkgs> {}; runCommand "unameNixDocker" {} "uname -a > $out")' --builders ssh://nix-docker --option system x86_64-linux
cat result

echo ""
echo ""
echo "All good, your builder is up and working!"