Rakefile

# -*- coding: utf-8 -*-
# -*- mode: ruby -*-
# vi: set ft=ruby :
#
# Tails: The Amnesic Incognito Live System
# Copyright © 2012 Tails developers <tails@boum.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

require 'date'
require 'libvirt'
require 'open3'
require 'rbconfig'
require 'uri'

require_relative 'vagrant/lib/tails_build_settings'

# Path to the directory which holds our Vagrantfile
VAGRANT_PATH = File.expand_path('../vagrant', __FILE__)

# Branches that are considered 'stable' (used to select SquashFS compression)
STABLE_BRANCH_NAMES = ['stable', 'testing']

EXPORTED_VARIABLES = [
  'MKSQUASHFS_OPTIONS',
  'TAILS_BUILD_FAILURE_RESCUE',
  'TAILS_DATE_OFFSET',
  'TAILS_MERGE_BASE_BRANCH',
  'TAILS_OFFLINE_MODE',
  'TAILS_PROXY',
  'TAILS_PROXY_TYPE',
  'TAILS_RAM_BUILD',
  'GIT_COMMIT',
  'GIT_REF',
  'BASE_BRANCH_GIT_COMMIT',
]
ENV['EXPORTED_VARIABLES'] = EXPORTED_VARIABLES.join(' ')

EXTERNAL_HTTP_PROXY = ENV['http_proxy']

# In-VM proxy URL
INTERNAL_HTTP_PROXY = "http://#{VIRTUAL_MACHINE_HOSTNAME}:3142"

ENV['ARTIFACTS'] ||= '.'

class CommandError < StandardError
  attr_reader :status, :stderr

  def initialize(message = nil, opts = {})
    opts[:status] ||= nil
    opts[:stderr] ||= nil
    @status = opts[:status]
    @stderr = opts[:stderr]
    super(message % {status: @status, stderr: @stderr})
  end
end

def run_command(*args)
  Process.wait Kernel.spawn(*args)
  if $?.exitstatus != 0
    raise CommandError.new("command #{args} failed with exit status " +
                           "%{status}", status: $?.exitstatus)
  end
end

def capture_command(*args)
  stdout, stderr, proc_status = Open3.capture3(*args)
  if proc_status.exitstatus != 0
    raise CommandError.new("command #{args} failed with exit status " +
                           "%{status}: %{stderr}",
                           stderr: stderr, status: proc_status.exitstatus)
  end
  return stdout, stderr
end

def git_helper(*args)
  question = args.first.end_with?('?')
  args.first.sub!(/\?$/, '')
  status = 0
  stdout = ''
  begin
    stdout, _ = capture_command('auto/scripts/utils.sh', *args)
  rescue CommandError => e
    status = e.status
  end
  if question
    return status == 0
  else
    return stdout.chomp
  end
end

class VagrantCommandError < CommandError
end

# Runs the vagrant command, letting stdout/stderr through. Throws an
# exception unless the vagrant command succeeds.
def run_vagrant(*args)
  run_command('vagrant', *args, :chdir => './vagrant')
rescue CommandError => e
  raise(VagrantCommandError, "'vagrant #{args}' command failed with exit " +
                             "status #{e.status}")
end

# Runs the vagrant command, not letting stdout/stderr through, and
# returns [stdout, stderr, Preocess:Status].
def capture_vagrant(*args)
  capture_command('vagrant', *args, :chdir => './vagrant')
rescue CommandError => e
  raise(VagrantCommandError, "'vagrant #{args}' command failed with exit " +
                             "status #{e.status}: #{e.stderr}")
end

[:run_vagrant, :capture_vagrant].each do |m|
  define_method "#{m}_ssh" do |*args|
    method(m).call('ssh', '-c', *args, '--', '-q')
  end
end

def vagrant_ssh_config(key)
  # Cache results
  if $vagrant_ssh_config.nil?
    $vagrant_ssh_config = capture_vagrant('ssh-config').first.split("\n") \
                           .map { |line| line.strip.split(/\s+/, 2) } .to_h
    # The path in the ssh-config output is quoted, which is not what
    # is expected outside of a shell, so let's get rid of the quotes.
    $vagrant_ssh_config['IdentityFile'].gsub!(/^"|"$/, '')
  end
  $vagrant_ssh_config[key]
end

def current_vm_cpus
  capture_vagrant_ssh('grep -c "^processor\s*:" /proc/cpuinfo').first.chomp.to_i
end

def vm_state
  out, _ = capture_vagrant('status')
  status_line = out.split("\n")[2]
  if    status_line['not created']
    return :not_created
  elsif status_line['shutoff']
    return :poweroff
  elsif status_line['running']
    return :running
  else
    raise "could not determine VM state"
  end
end

def enough_free_host_memory_for_ram_build?
  return false unless RbConfig::CONFIG['host_os'] =~ /linux/i

  begin
    usable_free_mem = `free`.split[12].to_i
    usable_free_mem > VM_MEMORY_FOR_RAM_BUILDS * 1024
  rescue
    false
  end
end

def free_vm_memory
  capture_vagrant_ssh('free').first.chomp.split[12].to_i
end

def enough_free_vm_memory_for_ram_build?
  free_vm_memory > BUILD_SPACE_REQUIREMENT * 1024
end

def enough_free_memory_for_ram_build?
  if vm_state == :running
    enough_free_vm_memory_for_ram_build?
  else
    enough_free_host_memory_for_ram_build?
  end
end

def is_release?
  git_helper('git_on_a_tag?')
end

def system_cpus
  return nil unless RbConfig::CONFIG['host_os'] =~ /linux/i

  begin
    File.read('/proc/cpuinfo').scan(/^processor\s+:/).count
  rescue
    nil
  end
end

task :parse_build_options do
  options = []

  # Default to in-memory builds if there is enough RAM available
  options << 'ram' if enough_free_memory_for_ram_build?

  # Default to build using the in-VM proxy
  options << 'vmproxy'

  # Default to fast compression on development branches
  options << 'gzipcomp' unless is_release?

  # Default to the number of system CPUs when we can figure it out
  cpus = system_cpus
  options << "cpus=#{cpus}" if cpus

  options += ENV['TAILS_BUILD_OPTIONS'].split if ENV['TAILS_BUILD_OPTIONS']

  options.uniq.each do |opt|
    case opt
    # Memory build settings
    when 'ram'
      ENV['TAILS_RAM_BUILD'] = '1'
    when 'noram'
      ENV['TAILS_RAM_BUILD'] = nil
    # Bootstrap cache settings
    # HTTP proxy settings
    when 'extproxy'
      abort "No HTTP proxy set, but one is required by TAILS_BUILD_OPTIONS. Aborting." unless EXTERNAL_HTTP_PROXY
      ENV['TAILS_PROXY'] = EXTERNAL_HTTP_PROXY
      ENV['TAILS_PROXY_TYPE'] = 'extproxy'
    when 'vmproxy'
      ENV['TAILS_PROXY'] = INTERNAL_HTTP_PROXY
      ENV['TAILS_PROXY_TYPE'] = 'vmproxy'
    when 'noproxy'
      ENV['TAILS_PROXY'] = nil
      ENV['TAILS_PROXY_TYPE'] = 'noproxy'
    when 'offline'
      ENV['TAILS_OFFLINE_MODE'] = '1'
    # SquashFS compression settings
    when 'gzipcomp'
      ENV['MKSQUASHFS_OPTIONS'] = '-comp gzip -Xcompression-level 1'
      if is_release?
        raise 'We must use the default compression when building releases!'
      end
    when 'defaultcomp'
      ENV['MKSQUASHFS_OPTIONS'] = nil
    # Virtual hardware settings
    when /machinetype=([a-zA-Z0-9_.-]+)/
      ENV['TAILS_BUILD_MACHINE_TYPE'] = $1
    when /cpus=(\d+)/
      ENV['TAILS_BUILD_CPUS'] = $1
    when /cpumodel=([a-zA-Z0-9_-]+)/
      ENV['TAILS_BUILD_CPU_MODEL'] = $1
    # Git settings
    when 'ignorechanges'
      ENV['TAILS_BUILD_IGNORE_CHANGES'] = '1'
    when /dateoffset=([-+]\d+)/
      ENV['TAILS_DATE_OFFSET'] = $1
    # Developer convenience features
    when 'keeprunning'
      $keep_running = true
      $force_cleanup = false
    when 'forcecleanup'
      $force_cleanup = true
      $keep_running = false
    when 'rescue'
      $keep_running = true
      ENV['TAILS_BUILD_FAILURE_RESCUE'] = '1'
    # Jenkins
    when 'mergebasebranch'
      ENV['TAILS_MERGE_BASE_BRANCH'] = '1'
    else
      raise "Unknown Tails build option '#{opt}'"
    end
  end

  if ENV['TAILS_OFFLINE_MODE'] == '1'
    if ENV['TAILS_PROXY'].nil?
      abort "You must use a caching proxy when building offline"
    end
  end
end

task :ensure_clean_repository do
  git_status = `git status --porcelain`
  unless git_status.empty?
    if ENV['TAILS_BUILD_IGNORE_CHANGES']
      $stderr.puts <<-END_OF_MESSAGE.gsub(/^        /, '')

        You have uncommitted changes in the Git repository. They will
        be ignored for the upcoming build:
        #{git_status}

      END_OF_MESSAGE
    else
      $stderr.puts <<-END_OF_MESSAGE.gsub(/^        /, '')

        You have uncommitted changes in the Git repository. Due to limitations
        of the build system, you need to commit them before building Tails:
        #{git_status}

        If you don't care about those changes and want to build Tails nonetheless,
        please add `ignorechanges` to the TAILS_BUILD_OPTIONS environment
        variable.

      END_OF_MESSAGE
      abort 'Uncommitted changes. Aborting.'
    end
  end
end

def list_artifacts
  user = vagrant_ssh_config('User')
  stdout = capture_vagrant_ssh("find '/home/#{user}/amnesia/' -maxdepth 1 " +
                                        "-name 'tails-*.iso*'").first
  stdout.split("\n")
rescue VagrantCommandError
  return Array.new
end

def remove_artifacts
  list_artifacts.each do |artifact|
    run_vagrant_ssh("sudo rm -f '#{artifact}'")
  end
end

task :ensure_clean_home_directory => ['vm:up'] do
  remove_artifacts
end

task :validate_http_proxy do
  if ENV['TAILS_PROXY']
    proxy_host = URI.parse(ENV['TAILS_PROXY']).host

    if proxy_host.nil?
      ENV['TAILS_PROXY'] = nil
      $stderr.puts "Ignoring invalid HTTP proxy."
      return
    end

    if ['localhost', '[::1]'].include?(proxy_host) || proxy_host.start_with?('127.0.0.')
      abort 'Using an HTTP proxy listening on the loopback is doomed to fail. Aborting.'
    end

    $stderr.puts "Using HTTP proxy: #{ENV['TAILS_PROXY']}"
  else
    $stderr.puts "No HTTP proxy set."
  end
end

task :validate_git_state do
  if git_helper('git_in_detached_head?') && not(git_helper('git_on_a_tag?'))
    raise 'We are in detached head but the current commit is not tagged'
  end
end

task :setup_environment => ['validate_git_state'] do
  ENV['GIT_COMMIT'] ||= git_helper('git_current_commit')
  ENV['GIT_REF'] ||= git_helper('git_current_head_name')
  if on_jenkins?
    jenkins_branch = (ENV['GIT_BRANCH'] || '').sub(/^origin\//, '')
    if not(is_release?) && jenkins_branch != ENV['GIT_REF']
      raise "We expected to build the Git ref '#{ENV['GIT_REF']}', but GIT_REF in the environment says '#{jenkins_branch}'. Aborting!"
    end
  end

  ENV['BASE_BRANCH_GIT_COMMIT'] = git_helper('git_base_branch_head')
  ['GIT_COMMIT', 'GIT_REF', 'BASE_BRANCH_GIT_COMMIT'].each do |var|
    if ENV[var].empty?
      raise "Variable '#{var}' is empty, which should not be possible" +
            "(validate_git_state must be buggy)"
    end
  end
end

task :maybe_clean_up_builder_vms do
  clean_up_builder_vms if $force_cleanup
end

desc 'Build Tails'
task :build => ['parse_build_options', 'ensure_clean_repository', 'maybe_clean_up_builder_vms', 'validate_git_state', 'setup_environment', 'validate_http_proxy', 'vm:up', 'ensure_clean_home_directory'] do

  begin
    if ENV['TAILS_RAM_BUILD'] && not(enough_free_memory_for_ram_build?)
      $stderr.puts <<-END_OF_MESSAGE.gsub(/^        /, '')

        The virtual machine is not currently set with enough memory to
        perform an in-memory build. Either remove the `ram` option from
        the TAILS_BUILD_OPTIONS environment variable, or shut the
        virtual machine down using `rake vm:halt` before trying again.

      END_OF_MESSAGE
      abort 'Not enough memory for the virtual machine to run an in-memory build. Aborting.'
    end

    if ENV['TAILS_BUILD_CPUS'] && current_vm_cpus != ENV['TAILS_BUILD_CPUS'].to_i
      $stderr.puts <<-END_OF_MESSAGE.gsub(/^        /, '')

        The virtual machine is currently running with #{current_vm_cpus}
        virtual CPU(s). In order to change that number, you need to
        stop the VM first, using `rake vm:halt`. Otherwise, please
        adjust the `cpus` options accordingly.

      END_OF_MESSAGE
      abort 'The virtual machine needs to be reloaded to change the number of CPUs. Aborting.'
    end

    exported_env = EXPORTED_VARIABLES.select { |k| ENV[k] }.
                   collect { |k| "#{k}='#{ENV[k]}'" }.join(' ')
    run_vagrant_ssh("#{exported_env} build-tails")

    artifacts = list_artifacts
    raise 'No build artifacts were found!' if artifacts.empty?
    user     = vagrant_ssh_config('User')
    hostname = vagrant_ssh_config('HostName')
    key_file = vagrant_ssh_config('IdentityFile')
    $stderr.puts "Retrieving artifacts from Vagrant build box."
    run_vagrant_ssh(
      "sudo chown #{user} " + artifacts.map { |a| "'#{a}'" } .join(' ')
    )
    fetch_command = [
      'scp',
      '-i', key_file,
      # We need this since the user will not necessarily have a
      # known_hosts entry. It is safe since an attacker must
      # compromise libvirt's network config or the user running the
      # command to modify the #{hostname} below.
      '-o', 'StrictHostKeyChecking=no',
      '-o', 'UserKnownHostsFile=/dev/null',
    ]
    fetch_command += artifacts.map { |a| "#{user}@#{hostname}:#{a}" }
    fetch_command << ENV['ARTIFACTS']
    run_command(*fetch_command)
    clean_up_builder_vms unless $keep_running
  ensure
    clean_up_builder_vms if $force_cleanup
  end
end

def has_box?
  not(capture_vagrant('box', 'list').grep(/^#{box_name}\s+\(libvirt,/).empty?)
end

def domain_name
  "#{box_name}_default"
end

def clean_up_builder_vms
  $virt = Libvirt::open("qemu:///system")

  clean_up_domain = Proc.new do |domain|
    next if domain.nil?
    domain.destroy if domain.active?
    domain.undefine
    begin
      $virt
        .lookup_storage_pool_by_name('default')
        .lookup_volume_by_name("#{domain.name}.img")
        .delete
    rescue Libvirt::RetrieveError
      # Expected if the pool or disk does not exist
    end
  end

  # Let's ensure that the VM we are about to create is cleaned up ...
  previous_domain = $virt.list_all_domains.find { |d| d.name == domain_name }
  if previous_domain && previous_domain.active?
    begin
      run_vagrant_ssh("mountpoint -q /var/cache/apt-cacher-ng")
    rescue VagrantCommandError
    # Nothing to unmount.
    else
      run_vagrant_ssh("sudo systemctl stop apt-cacher-ng.service")
      run_vagrant_ssh("sudo umount /var/cache/apt-cacher-ng")
      run_vagrant_ssh("sudo sync")
    end
  end
  clean_up_domain.call(previous_domain)

  # ... and the same for any residual VM based on another box (=>
  # another domain name) that Vagrant still keeps track of.
  old_domain =
    begin
      old_domain_uuid =
        open('vagrant/.vagrant/machines/default/libvirt/id', 'r') { |f| f.read }
        .strip
      $virt.lookup_domain_by_uuid(old_domain_uuid)
    rescue Errno::ENOENT, Libvirt::RetrieveError
      # Expected if we don't have vagrant/.vagrant, or if the VM was
      # undefined for other reasons (e.g. manually).
      nil
    end
  clean_up_domain.call(old_domain)

  # We could use `vagrant destroy` here but due to vagrant-libvirt's
  # upstream issue #746 we then risk losing the apt-cacher-ng data.
  # Since we essentially implement `vagrant destroy` without this bug
  # above, but in a way so it works even if `vagrant/.vagrant` does
  # not exist, let's just do what is safest, i.e. avoiding `vagrant
  # destroy`. For details, see the upstream issue:
  #   https://github.com/vagrant-libvirt/vagrant-libvirt/issues/746
  FileUtils.rm_rf('vagrant/.vagrant')
ensure
  $virt.close
end

desc "Remove all libvirt volumes named tails-builder-* (run at your own risk!)"
task :clean_up_libvirt_volumes do
  $virt = Libvirt::open("qemu:///system")
  begin
    pool = $virt.lookup_storage_pool_by_name('default')
  rescue Libvirt::RetrieveError
    # Expected if the pool does not exist
  else
    for disk in pool.list_volumes do
      if /^tails-builder-/.match(disk)
        begin
          pool.lookup_volume_by_name(disk).delete
        rescue Libvirt::RetrieveError
          # Expected if the disk does not exist
        end
      end
    end
  ensure
    $virt.close
  end
end

def on_jenkins?
  !!ENV['JENKINS_URL']
end

desc 'Test Tails'
task :test do
  args = ARGV.drop_while { |x| x == 'test' || x == '--' }
  if on_jenkins?
    args += ['--'] unless args.include? '--'
    if not(is_release?)
      args += ['--tag', '~@fragile']
    end
    base_branch = git_helper('base_branch')
    if git_helper('git_only_doc_changes_since?', "origin/#{base_branch}") then
      args += ['--tag', '@doc']
    end
  end
  run_command('./run_test_suite', *args)
end

desc 'Clean up all build related files'
task :clean_all => ['vm:destroy', 'basebox:clean_all']

namespace :vm do
  desc 'Start the build virtual machine'
  task :up => ['parse_build_options', 'validate_http_proxy', 'setup_environment', 'basebox:create'] do
    case vm_state
    when :not_created
      clean_up_builder_vms
    end
    begin
      run_vagrant('up')
    rescue VagrantCommandError => e
      clean_up_builder_vms if $force_cleanup
      raise e
    end
  end

  desc 'SSH into the builder VM'
  task :ssh do
    run_vagrant('ssh')
  end

  desc 'Stop the build virtual machine'
  task :halt do
    run_vagrant('halt')
  end

  desc 'Re-run virtual machine setup'
  task :provision => ['parse_build_options', 'validate_http_proxy', 'setup_environment'] do
    run_vagrant('provision')
  end

  desc "Destroy build virtual machine (clean up all files except the vmproxy's apt-cacher-ng data)"
  task :destroy do
    clean_up_builder_vms
  end
end

namespace :basebox do

  desc 'Create and import the base box unless already done'
  task :create do
    next if has_box?
    $stderr.puts <<-END_OF_MESSAGE.gsub(/^      /, '')

      This is the first time we are using this Vagrant base box so we
      will have to bootstrap by building it from scratch. This will
      take around 20 minutes (depending on your hardware) plus the
      time needed for downloading around 250 MiB of Debian packages.

    END_OF_MESSAGE
    box_dir = VAGRANT_PATH + '/definitions/tails-builder'
    run_command("#{box_dir}/generate-tails-builder-box.sh")
    # Let's use an absolute path since run_vagrant changes the working
    # directory but File.delete doesn't
    box_path = "#{box_dir}/#{box_name}.box"
    run_vagrant('box', 'add', '--name', box_name, box_path)
    File.delete(box_path)
    end

  def basebox_date(box)
    Date.parse(/^tails-builder-[^-]+-[^-]+-(\d{8})/.match(box)[1])
  end

  def baseboxes
    capture_vagrant('box', 'list').first.lines
      .grep(/^tails-builder-.*/)
      .map { |x| x.chomp.sub(/\s.*$/, '') }
  end

  def clean_up_basebox(box)
    run_vagrant('box', 'remove', '--force', box)
    begin
      $virt = Libvirt::open("qemu:///system")
      $virt
        .lookup_storage_pool_by_name('default')
        .lookup_volume_by_name("#{box}_vagrant_box_image_0.img")
        .delete
    rescue Libvirt::RetrieveError
      # Expected if the pool or disk does not exist
    ensure
      $virt.close
    end
  end

  desc 'Remove all base boxes'
  task :clean_all do
    baseboxes.each { |box| clean_up_basebox(box) }
  end

  desc 'Remove all base boxes older than six months'
  task :clean_old do
    boxes = baseboxes
    # We always want to keep the newest basebox
    boxes.sort! { |a, b| basebox_date(a) <=> basebox_date(b) }
    boxes.pop
    boxes.each do |box|
      if basebox_date(box) < Date.today - 365.0/3.0
        clean_up_basebox(box)
      end
    end
  end
end