vagrant/lib/vagrant/util/subprocess.rb

355 lines
13 KiB
Ruby

require 'thread'
require 'childprocess'
require 'log4r'
require 'vagrant/util/io'
require 'vagrant/util/platform'
require 'vagrant/util/safe_chdir'
require 'vagrant/util/which'
module Vagrant
module Util
# Execute a command in a subprocess, gathering the results and
# exit status.
#
# This class also allows you to read the data as it is outputted
# from the subprocess in real time, by simply passing a block to
# the execute method.
class Subprocess
# Convenience method for executing a method.
def self.execute(*command, &block)
new(*command).execute(&block)
end
def initialize(*command)
@options = command.last.is_a?(Hash) ? command.pop : {}
@command = command.dup
@command[0] = Which.which(@command[0]) if !File.file?(@command[0])
if !@command[0]
raise Errors::CommandUnavailableWindows, file: command[0] if Platform.windows?
raise Errors::CommandUnavailable, file: command[0]
end
@logger = Log4r::Logger.new("vagrant::util::subprocess")
end
# @return [TrueClass, FalseClass] subprocess is currently running
def running?
!!(@process && @process.alive?)
end
# Stop the subprocess if running
#
# @return [TrueClass] FalseClass] true if process was running and stopped
def stop
if @process && @process.alive?
@process.stop
true
else
false
end
end
# Start the process
#
# @return [Result]
def execute
# Get the timeout, if we have one
timeout = @options[:timeout]
# Get the working directory
workdir = @options[:workdir] || Dir.pwd
# Get what we're interested in being notified about
notify = @options[:notify] || []
notify = [notify] if !notify.is_a?(Array)
if notify.empty? && block_given?
# If a block is given, subscribers must be given, otherwise the
# block is never called. This is usually NOT what you want, so this
# is an error.
message = "A list of notify subscriptions must be given if a block is given"
raise ArgumentError, message
end
# Let's get some more useful booleans that we access a lot so
# we're not constantly calling an `include` check
notify_table = {}
notify_table[:stderr] = notify.include?(:stderr)
notify_table[:stdout] = notify.include?(:stdout)
notify_stdin = notify.include?(:stdin)
# Build the ChildProcess
@logger.info("Starting process: #{@command.inspect}")
@process = process = ChildProcess.build(*@command)
# Create the pipes so we can read the output in real time as
# we execute the command.
stdout, stdout_writer = ::IO.pipe
stderr, stderr_writer = ::IO.pipe
process.io.stdout = stdout_writer
process.io.stderr = stderr_writer
process.duplex = true
# Special installer-related things
if Vagrant.in_installer?
installer_dir = Vagrant.installer_embedded_dir.to_s.downcase
# If we're in an installer on Mac and we're executing a command
# in the installer context, then force DYLD_LIBRARY_PATH to look
# at our libs first.
if Platform.darwin?
if @command[0].downcase.include?(installer_dir)
@logger.info("Command in the installer. Specifying DYLD_LIBRARY_PATH...")
process.environment["DYLD_LIBRARY_PATH"] =
"#{installer_dir}/lib:#{ENV["DYLD_LIBRARY_PATH"]}"
else
@logger.debug("Command not in installer, not touching env vars.")
end
if File.setuid?(@command[0]) || File.setgid?(@command[0])
@logger.info("Command is setuid/setgid, clearing DYLD_LIBRARY_PATH")
process.environment["DYLD_LIBRARY_PATH"] = ""
end
end
# If the command that is being run is not inside the installer, reset
# the original environment - this is required for shelling out to
# other subprocesses that depend on environment variables (like Ruby
# and $GEM_PATH for example)
internal = [installer_dir, Vagrant.user_data_path.to_s.downcase].
any? { |path| @command[0].downcase.include?(path) }
if !internal
@logger.info("Command not in installer, restoring original environment...")
jailbreak(process.environment)
end
# If running within an AppImage and calling external executable. When
# executable is external set the LD_LIBRARY_PATH to host values.
if ENV["VAGRANT_APPIMAGE"]
embed_path = Pathname.new(Vagrant.installer_embedded_dir).expand_path.to_s
exec_path = Pathname.new(@command[0]).expand_path.to_s
if !exec_path.start_with?(embed_path) && ENV["VAGRANT_APPIMAGE_LD_LIBRARY_PATH"]
@logger.info("Detected AppImage environment and request to external binary. Updating library path.")
@logger.debug("Setting LD_LIBRARY_PATH to #{ENV["VAGRANT_APPIMAGE_LD_LIBRARY_PATH"]}")
process.environment["LD_LIBRARY_PATH"] = ENV["VAGRANT_APPIMAGE_LD_LIBRARY_PATH"].to_s
end
end
else
@logger.info("Vagrant not running in installer, restoring original environment...")
jailbreak(process.environment)
end
# Set the environment on the process if we must
if @options[:env]
@options[:env].each do |k, v|
process.environment[k] = v
end
end
# Start the process
begin
SafeChdir.safe_chdir(workdir) do
process.start
end
rescue ChildProcess::LaunchError => ex
# Raise our own version of the error so that users of the class
# don't need to be aware of ChildProcess
raise LaunchError.new(ex.message)
end
# Make sure the stdin does not buffer
process.io.stdin.sync = true
if RUBY_PLATFORM != "java"
# On Java, we have to close after. See down the method...
# Otherwise, we close the writers right here, since we're
# not on the writing side.
stdout_writer.close
stderr_writer.close
end
# Create a dictionary to store all the output we see.
io_data = { stdout: "", stderr: "" }
# Record the start time for timeout purposes
start_time = Time.now.to_i
open_readers = [stdout, stderr]
open_writers = notify_stdin ? [process.io.stdin] : []
@logger.debug("Selecting on IO")
while true
results = ::IO.select(open_readers, open_writers, nil, 0.1)
results ||= []
readers = results[0]
writers = results[1]
# Check if we have exceeded our timeout
raise TimeoutExceeded, process.pid if timeout && (Time.now.to_i - start_time) > timeout
# Check the readers to see if they're ready
if readers && !readers.empty?
readers.each do |r|
# Read from the IO object
data = IO.read_until_block(r)
# We don't need to do anything if the data is empty
next if data.empty?
io_name = r == stdout ? :stdout : :stderr
@logger.debug("#{io_name}: #{data.chomp}")
io_data[io_name] += data
yield io_name, data if block_given? && notify_table[io_name]
end
end
# Break out if the process exited. We have to do this before
# attempting to write to stdin otherwise we'll get a broken pipe
# error.
break if process.exited?
# Check the writers to see if they're ready, and notify any listeners
if writers && !writers.empty? && block_given?
yield :stdin, process.io.stdin
# if the callback closed stdin, we should remove it, because
# IO.select() will throw if called with a closed io.
if process.io.stdin.closed?
open_writers = []
end
end
end
# Wait for the process to end.
begin
remaining = (timeout || 32000) - (Time.now.to_i - start_time)
remaining = 0 if remaining < 0
@logger.debug("Waiting for process to exit. Remaining to timeout: #{remaining}")
process.poll_for_exit(remaining)
rescue ChildProcess::TimeoutError
raise TimeoutExceeded, process.pid
end
@logger.debug("Exit status: #{process.exit_code}")
# Read the final output data, since it is possible we missed a small
# amount of text between the time we last read data and when the
# process exited.
[stdout, stderr].each do |io|
# Read the extra data, ignoring if there isn't any
extra_data = IO.read_until_block(io)
next if extra_data == ""
# Log it out and accumulate
io_name = io == stdout ? :stdout : :stderr
io_data[io_name] += extra_data
@logger.debug("#{io_name}: #{extra_data.chomp}")
# Yield to any listeners any remaining data
yield io_name, extra_data if block_given? && notify_table[io_name]
end
if RUBY_PLATFORM == "java"
# On JRuby, we need to close the writers after the process,
# for some reason. See GH-711.
stdout_writer.close
stderr_writer.close
end
# Return an exit status container
return Result.new(process.exit_code, io_data[:stdout], io_data[:stderr])
ensure
if process && process.alive?
# Make sure no matter what happens, the process exits
process.stop(2)
end
end
protected
# An error which raises when a process fails to start
class LaunchError < StandardError; end
# An error which occurs when the process doesn't end within
# the given timeout.
class TimeoutExceeded < StandardError
attr_reader :pid
def initialize(pid)
super()
@pid = pid
end
end
# Container class to store the results of executing a subprocess.
class Result
attr_reader :exit_code
attr_reader :stdout
attr_reader :stderr
def initialize(exit_code, stdout, stderr)
@exit_code = exit_code
@stdout = stdout
@stderr = stderr
end
end
private
# This is, quite possibly, the saddest function in all of Vagrant.
#
# If a user is running Vagrant via Bundler (but not via the official
# installer), we want to reset to the "original" environment so that when
# shelling out to other Ruby processes (specifically), the original
# environment is restored. This is super important for things like
# rbenv and chruby, who rely on environment variables to locate gems, but
# Bundler stomps on those environment variables like an angry T-Rex after
# watching Jurassic Park 2 and realizing they replaced you with CGI.
#
# If a user is running in Vagrant via the official installer, BUT trying
# to execute a subprocess *outside* of the installer, we want to reset to
# the "original" environment. In this case, the Vagrant installer actually
# knows what the original environment was and replaces it completely.
#
# Finally, we reset any Bundler-specific environment variables, since the
# subprocess being called could, itself, be Bundler. And Bundler does not
# behave very nicely in these circumstances.
#
# This function was added in Vagrant 1.7.3, but there is a failsafe
# because the author doesn't trust himself that this functionality won't
# break existing assumptions, so users can specify
# `VAGRANT_SKIP_SUBPROCESS_JAILBREAK` and none of the above will happen.
#
# This function modifies the given hash in place!
#
# @return [nil]
def jailbreak(env = {})
return if ENV.key?("VAGRANT_SKIP_SUBPROCESS_JAILBREAK")
if defined?(::Bundler) && defined?(::Bundler::ORIGINAL_ENV)
env.replace(::Bundler::ORIGINAL_ENV)
end
env.merge!(Vagrant.original_env)
# Bundler does this, so I guess we should as well, since I think it
# other subprocesses that use Bundler will reload it
env["MANPATH"] = ENV["BUNDLE_ORIG_MANPATH"]
# Replace all current environment BUNDLE_ variables to nil
ENV.each do |k,_|
env[k] = nil if k[0,7] == "BUNDLE_"
end
# If RUBYOPT was set, unset it with Bundler
if ENV.key?("RUBYOPT")
env["RUBYOPT"] = ENV["RUBYOPT"].sub("-rbundler/setup", "")
end
nil
end
end
end
end