vagrant/plugins/communicators/ssh/communicator.rb

284 lines
9.6 KiB
Ruby

require 'timeout'
require 'log4r'
require 'net/ssh'
require 'net/scp'
require 'vagrant/util/ansi_escape_code_remover'
require 'vagrant/util/file_mode'
require 'vagrant/util/platform'
require 'vagrant/util/retryable'
require 'vagrant/util/ssh'
module VagrantPlugins
module CommunicatorSSH
# This class provides communication with the VM via SSH.
class Communicator < Vagrant.plugin("2", :communicator)
include Vagrant::Util::ANSIEscapeCodeRemover
include Vagrant::Util::Retryable
def self.match?(machine)
# All machines are currently expected to have SSH.
true
end
def initialize(machine)
@machine = machine
@logger = Log4r::Logger.new("vagrant::communication::ssh")
@connection = nil
end
def ready?
@logger.debug("Checking whether SSH is ready...")
# Attempt to connect. This will raise an exception if it fails.
connect
# If we reached this point then we successfully connected
@logger.info("SSH is ready!")
true
rescue Vagrant::Errors::VagrantError => e
# We catch a `VagrantError` which would signal that something went
# wrong expectedly in the `connect`, which means we didn't connect.
@logger.info("SSH not up: #{e.inspect}")
return false
end
def execute(command, opts=nil, &block)
opts = {
:error_check => true,
:error_class => Vagrant::Errors::VagrantError,
:error_key => :ssh_bad_exit_status,
:command => command,
:sudo => false
}.merge(opts || {})
# Connect via SSH and execute the command in the shell.
exit_status = connect do |connection|
shell_execute(connection, command, opts[:sudo], &block)
end
# Check for any errors
if opts[:error_check] && exit_status != 0
# The error classes expect the translation key to be _key,
# but that makes for an ugly configuration parameter, so we
# set it here from `error_key`
error_opts = opts.merge(:_key => opts[:error_key])
raise opts[:error_class], error_opts
end
# Return the exit status
exit_status
end
def sudo(command, opts=nil, &block)
# Run `execute` but with the `sudo` option.
opts = { :sudo => true }.merge(opts || {})
execute(command, opts, &block)
end
def download(from, to=nil)
@logger.debug("Downloading: #{from} to #{to}")
scp_connect do |scp|
scp.download!(from, to)
end
end
def test(command, opts=nil)
opts = { :error_check => false }.merge(opts || {})
execute(command, opts) == 0
end
def upload(from, to)
@logger.debug("Uploading: #{from} to #{to}")
scp_connect do |scp|
# Open file read only to fix issue [GH-1036]
scp.upload!(File.open(from, "r"), to)
end
rescue RuntimeError => e
# Net::SCP raises a runtime error for this so the only way we have
# to really catch this exception is to check the message to see if
# it is something we care about. If it isn't, we re-raise.
raise if e.message !~ /Permission denied/
# Otherwise, it is a permission denied, so let's raise a proper
# exception
raise Vagrant::Errors::SCPPermissionDenied, :path => from.to_s
end
protected
# Opens an SSH connection and yields it to a block.
def connect
if @connection && !@connection.closed?
# There is a chance that the socket is closed despite us checking
# 'closed?' above. To test this we need to send data through the
# socket.
begin
@connection.exec!("")
rescue IOError
@logger.info("Connection has been closed. Not re-using.")
@connection = nil
end
# If the @connection is still around, then it is valid,
# and we use it.
if @connection
@logger.debug("Re-using SSH connection.")
return yield @connection if block_given?
return
end
end
# XXX: We need to raise some exception if SSH is not ready
ssh_info = @machine.ssh_info
# Build the options we'll use to initiate the connection via Net::SSH
opts = {
:port => ssh_info[:port],
:keys => [ssh_info[:private_key_path]],
:keys_only => true,
:user_known_hosts_file => [],
:paranoid => false,
:config => false,
:forward_agent => ssh_info[:forward_agent]
}
# Check that the private key permissions are valid
Vagrant::Util::SSH.check_key_permissions(ssh_info[:private_key_path])
# Connect to SSH, giving it a few tries
connection = nil
begin
# These are the exceptions that we retry because they represent
# errors that are generally fixed from a retry and don't
# necessarily represent immediate failure cases.
exceptions = [
Errno::ECONNREFUSED,
Errno::EHOSTUNREACH,
Net::SSH::Disconnect,
Timeout::Error
]
connection = retryable(:tries => @machine.config.ssh.max_tries, :on => exceptions) do
Timeout.timeout(@machine.config.ssh.timeout) do
@logger.info("Attempting to connect to SSH: #{ssh_info[:host]}:#{ssh_info[:port]}")
Net::SSH.start(ssh_info[:host], ssh_info[:username], opts)
end
end
rescue Timeout::Error
# This happens if we continued to timeout when attempting to connect.
raise Vagrant::Errors::SSHConnectionTimeout
rescue Net::SSH::AuthenticationFailed
# This happens if authentication failed. We wrap the error in our
# own exception.
raise Vagrant::Errors::SSHAuthenticationFailed
rescue Net::SSH::Disconnect
# This happens if the remote server unexpectedly closes the
# connection. This is usually raised when SSH is running on the
# other side but can't properly setup a connection. This is
# usually a server-side issue.
raise Vagrant::Errors::SSHDisconnected
rescue Errno::ECONNREFUSED
# This is raised if we failed to connect the max amount of times
raise Vagrant::Errors::SSHConnectionRefused
rescue Errno::EHOSTDOWN
# This is raised if we get an ICMP DestinationUnknown error.
raise Vagrant::Errors::SSHHostDown
rescue NotImplementedError
# This is raised if a private key type that Net-SSH doesn't support
# is used. Show a nicer error.
raise Vagrant::Errors::SSHKeyTypeNotSupported
end
@connection = connection
# This is hacky but actually helps with some issues where
# Net::SSH is simply not robust enough to handle... see
# issue #391, #455, etc.
sleep 4
# Yield the connection that is ready to be used and
# return the value of the block
return yield connection if block_given?
end
# Executes the command on an SSH connection within a login shell.
def shell_execute(connection, command, sudo=false)
@logger.info("Execute: #{command} (sudo=#{sudo.inspect})")
exit_status = nil
# Determine the shell to execute. If we are using `sudo` then we
# need to wrap the shell in a `sudo` call.
shell = @machine.config.ssh.shell
shell = "sudo -H #{shell}" if sudo
# Open the channel so we can execute or command
channel = connection.open_channel do |ch|
ch.exec(shell) do |ch2, _|
# Setup the channel callbacks so we can get data and exit status
ch2.on_data do |ch3, data|
if block_given?
# Filter out the clear screen command
data = remove_ansi_escape_codes(data)
@logger.debug("stdout: #{data}")
yield :stdout, data
end
end
ch2.on_extended_data do |ch3, type, data|
if block_given?
# Filter out the clear screen command
data = remove_ansi_escape_codes(data)
@logger.debug("stderr: #{data}")
yield :stderr, data
end
end
ch2.on_request("exit-status") do |ch3, data|
exit_status = data.read_long
@logger.debug("Exit status: #{exit_status}")
end
# Set the terminal
ch2.send_data "export TERM=vt100\n"
# Output the command
ch2.send_data "#{command}\n"
# Remember to exit or this channel will hang open
ch2.send_data "exit\n"
# Send eof to let server know we're done
ch2.eof!
end
end
# Wait for the channel to complete
channel.wait
# Return the final exit status
return exit_status
end
# Opens an SCP connection and yields it so that you can download
# and upload files.
def scp_connect
# Connect to SCP and yield the SCP object
connect do |connection|
scp = Net::SCP.new(connection)
return yield scp
end
rescue Net::SCP::Error => e
# If we get the exit code of 127, then this means SCP is unavailable.
raise Vagrant::Errors::SCPUnavailable if e.message =~ /\(127\)/
# Otherwise, just raise the error up
raise
end
end
end
end