lib/specinfra/backend/docker_lxc.rb
# encoding: UTF-8
#
# Author:: Xabier de Zuazo (<xabier@zuazo.org>)
# Copyright:: Copyright (c) 2015 Xabier de Zuazo
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
require 'specinfra/backend/docker'
require 'specinfra/backend/docker_lxc/shell_helpers'
require 'specinfra/backend/docker_lxc/exceptions'
# Command Execution Framework for Serverspec, Itamae and so on.
module Specinfra
# Specinfra backend types.
module Backend
# Specinfra and Serverspec backend for Docker LXC execution driver.
class DockerLxc < Docker
include Specinfra::Backend::DockerLxc::ShellHelpers
protected
# Generates `lxc-attach` command to run.
#
# @param cmd [String] the commands to run inside docker.
# @return [Array] the command to run as unescaped array.
def lxc_attach_command(cmd)
id = @container.id
['lxc-attach', '-n', id, '--', 'sh', '-c', cmd]
end
# Parses `lxc-attach` command output and raises an exception if it is an
# error from the `lxc-attach` program.
#
# @param stderr [String] command *stderr* output.
# @param exit_status [Fixnum] command exit status.
# @return nil
def lxc_attach_result_assert(stderr, exit_status)
return if exit_status == 0
return if stderr.match(/\A(lxc-attach|lxc_container|sudo): /).nil?
fail LxcAttachError, stderr
end
# Parses a rescued exception and returns the command result.
#
# @param exception [Exception] the exception to parse.
# @param cmd [Array<String>, String] the command (without `lxc-attach`).
# @param stdout [String] the *stdout* output.
# @param stderr [String] the *stderr* output.
# @param status [Fixnum] the command exit status.
# @return [Specinfra::CommandResult] the generated result object.
# @api public
def erroneous_result(cmd, exception, stdout, stderr, status)
err =
if stderr.nil?
[exception.message] + exception.backtrace
else
[stderr]
end
sta = status.is_a?(Fixnum) && status != 0 ? status : 1
rspec_example_metadata(cmd, stdout, err.join)
CommandResult.new(stdout: stdout, stderr: err.join, exit_status: sta)
end
# Updates RSpec metadata used by Serverspec.
#
# @param cmd [Array<String>, String] the command (without `lxc-attach`).
# @param stdout [String] the *stdout* output.
# @param stderr [String] the *stderr* output.
# @return nil
# @api public
def rspec_example_metadata(cmd, stdout, stderr)
return unless @example
@example.metadata[:command] = escape_command(cmd)
@example.metadata[:stdout] = stdout
@example.metadata[:stderr] = stderr
end
# Runs a command inside a Docker container.
#
# @param cmd [String] the command to run.
# @param opts [Hash] options to pass to {Open3.popen3}.
# @return [Specinfra::CommandResult] the result.
# @api public
def docker_run!(cmd, opts = {})
stdout, stderr, status = shell_command!(lxc_attach_command(cmd), opts)
lxc_attach_result_assert(stderr, status)
rspec_example_metadata(cmd, stdout, stderr)
CommandResult.new(stdout: stdout, stderr: stderr, exit_status: status)
rescue LxcAttachError
raise
rescue => e
@container.kill
erroneous_result(cmd, e, stdout, stderr, status)
end
end
end
end