lxc-config/hooks/update-mounts

#!/usr/bin/env ruby

require 'pathname'
require_relative "lib/lxc"

LXC_ROOT = Pathname.new("/data/containers")
FSTAB_D = Pathname.new("/etc/fstab.d")
SYS_MOUNT = 165
MS_BIND = 4096

def mount(src_path, dest_path, mounts)
  unless src_path.exist?
    abort "container directory for shared mount does not exists #{dest_path}"
  end
  unless src_path.exist?
    abort "container directory for shared mount does not exists #{src_path}"
  end
  entries = mounts.map do |src, dest|
    src = src.gsub(/^\//, "")

    src_mount = dest_path.join(src)
    if dest == true
      dest_mount = src_path.join(src)
    else
      dest_mount = src_path.join(dest.gsub(/^\//, ""))
    end
    puts ("mkdir -p #{dest_mount}")
    FileUtils.mkdir_p(dest_mount)
    syscall(SYS_MOUNT, src_mount.to_s, dest_mount.to_s, "none", MS_BIND, 0)
  end

  entries
end

def main
  registry = Lxc::Registry.new
  network = registry.data["network"] || {}
  network.each do |name, container|
    src_path = LXC_ROOT.join(name, "rootfs")
    containers = container["mounts"]
    next if containers.nil?

    containers.each do |dest_container, mounts|
      dest_path = LXC_ROOT.join(dest_container, "rootfs")
      mount(src_path, dest_path, mounts)
    end
  end
end

main