Module: Ohai::Mixin::Command
- Included in:
- DSL::Plugin
- Defined in:
- lib/ohai/mixin/command.rb
Class Method Summary collapse
-
.popen4(cmd, args = {}, &b) ⇒ Object
This is taken directly from Ara T Howard’s Open4 library, and then modified to suit the needs of Ohai.
- .run_command(args = {}) ⇒ Object
- .shell_out(cmd) ⇒ Object
Instance Method Summary collapse
- #run_command_unix(command, timeout) ⇒ Object (also: #run_command_backend)
- #run_command_windows(command, timeout) ⇒ Object
Class Method Details
.popen4(cmd, args = {}, &b) ⇒ Object
This is taken directly from Ara T Howard’s Open4 library, and then modified to suit the needs of Ohai. Any bugs here are most likely my own, and not Ara’s.
The original appears in external/open4.rb in its unmodified form.
Thanks Ara!
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# File 'lib/ohai/mixin/command.rb', line 126 def popen4(cmd, args={}, &b) ## Disable garbage collection to work around possible bug in MRI # Ruby 1.8 suffers from intermittent segfaults believed to be due to GC while IO.select # See OHAI-330 / CHEF-2916 / CHEF-1305 GC.disable # Waitlast - this is magic. # # Do we wait for the child process to die before we yield # to the block, or after? That is the magic of waitlast. # # By default, we are waiting before we yield the block. args[:waitlast] ||= false args[:user] ||= nil unless args[:user].kind_of?(Integer) args[:user] = Etc.getpwnam(args[:user]).uid if args[:user] end args[:group] ||= nil unless args[:group].kind_of?(Integer) args[:group] = Etc.getgrnam(args[:group]).gid if args[:group] end args[:environment] ||= {} # Default on C locale so parsing commands output can be done # independently of the node's default locale. # "LC_ALL" could be set to nil, in which case we also must ignore it. unless args[:environment].has_key?("LC_ALL") args[:environment]["LC_ALL"] = "C" end pw, pr, pe, ps = IO.pipe, IO.pipe, IO.pipe, IO.pipe verbose = $VERBOSE begin $VERBOSE = nil ps.last.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) cid = fork { Process.setsid pw.last.close STDIN.reopen pw.first pw.first.close pr.first.close STDOUT.reopen pr.last pr.last.close pe.first.close STDERR.reopen pe.last pe.last.close STDOUT.sync = STDERR.sync = true if args[:group] Process.egid = args[:group] Process.gid = args[:group] end if args[:user] Process.euid = args[:user] Process.uid = args[:user] end args[:environment].each do |key,value| ENV[key] = value end if args[:umask] umask = ((args[:umask].respond_to?(:oct) ? args[:umask].oct : args[:umask].to_i) & 007777) File.umask(umask) end begin if cmd.kind_of?(Array) exec(*cmd) else exec(cmd) end raise 'forty-two' rescue Exception => e Marshal.dump(e, ps.last) ps.last.flush end ps.last.close unless (ps.last.closed?) exit! } ensure $VERBOSE = verbose end [pw.first, pr.last, pe.last, ps.last].each{|fd| fd.close} begin e = Marshal.load ps.first pw.last.close pr.first.close pe.first.close Process.wait(cid) raise(Exception === e ? e : "unknown failure!") rescue EOFError # If we get an EOF error, then the exec was successful 42 ensure ps.first.close end pw.last.sync = true pi = [pw.last, pr.first, pe.first] if b begin if args[:waitlast] b[cid, *pi] # send EOF so that if the child process is reading from STDIN # it will actually finish up and exit pi[0].close_write Process.waitpid2(cid).last else # This took some doing. # The trick here is to close STDIN # Then set our end of the childs pipes to be O_NONBLOCK # Then wait for the child to die, which means any IO it # wants to do must be done - it's dead. If it isn't, # it's because something totally skanky is happening, # and we don't care. o = StringIO.new e = StringIO.new #pi[0].close stdout = pi[1] stderr = pi[2] stdout.sync = true stderr.sync = true stdout.fcntl(Fcntl::F_SETFL, pi[1].fcntl(Fcntl::F_GETFL) | Fcntl::O_NONBLOCK) stderr.fcntl(Fcntl::F_SETFL, pi[2].fcntl(Fcntl::F_GETFL) | Fcntl::O_NONBLOCK) stdout_finished = false stderr_finished = false results = nil while !stdout_finished || !stderr_finished begin channels_to_watch = [] channels_to_watch << stdout if !stdout_finished channels_to_watch << stderr if !stderr_finished ready = IO.select(channels_to_watch, nil, nil, 1.0) rescue Errno::EAGAIN ensure results = Process.waitpid2(cid, Process::WNOHANG) if results stdout_finished = true stderr_finished = true end end if ready && ready.first.include?(stdout) line = results ? stdout.gets(nil) : stdout.gets if line o.write(line) else stdout_finished = true end end if ready && ready.first.include?(stderr) line = results ? stderr.gets(nil) : stderr.gets if line e.write(line) else stderr_finished = true end end end results = Process.waitpid2(cid) unless results o.rewind e.rewind # **OHAI-275** # The way we read from the pipes causes ruby to mark the strings # as ASCII-8BIT (i.e., binary), but the content should be encoded # as the default external encoding. For example, a command may # return data encoded as UTF-8, but the strings will be marked as # ASCII-8BIT. Later, when you attempt to print the values as # UTF-8, Ruby will try to convert them and fail, raising an # error. # # Ruby always marks strings as binary when read from IO in # incomplete chunks, since you may have split the data within a # multibyte char. In our case, we concat the chunks back # together, so any multibyte chars will be reassembled. # # Note that all of this applies only to Ruby 1.9, which we check # for by making sure that the Encoding class exists and strings # have encoding methods. if "".respond_to?(:force_encoding) && defined?(Encoding) o.string.force_encoding(Encoding.default_external) o.string.encode!('UTF-8', :invalid => :replace, :undef => :replace, :replace => '?') e.string.force_encoding(Encoding.default_external) e.string.encode!('UTF-8', :invalid => :replace, :undef => :replace, :replace => '?') end b[cid, pi[0], o, e] results.last end ensure pi.each{|fd| fd.close unless fd.closed?} end else [cid, pw.last, pr.first, pe.first] end rescue Errno::ENOENT raise Ohai::Exceptions::Exec, "command #{cmd} doesn't exist or is not in the PATH" ensure # we disabled GC entering GC.enable end |
.run_command(args = {}) ⇒ Object
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# File 'lib/ohai/mixin/command.rb', line 39 def run_command(args={}) if args.has_key?(:creates) if File.exists?(args[:creates]) Ohai::Log.debug("Skipping #{args[:command]} - creates #{args[:creates]} exists.") return false end end stdout_string = nil stderr_string = nil args[:cwd] ||= Dir.tmpdir unless File.directory?(args[:cwd]) raise Ohai::Exceptions::Exec, "#{args[:cwd]} does not exist or is not a directory" end status = nil Dir.chdir(args[:cwd]) do status, stdout_string, stderr_string = run_command_backend(args[:command], args[:timeout]) if stdout_string Ohai::Log.debug("---- Begin #{args[:command]} STDOUT ----") Ohai::Log.debug(stdout_string.strip) Ohai::Log.debug("---- End #{args[:command]} STDOUT ----") end if stderr_string Ohai::Log.debug("---- Begin #{args[:command]} STDERR ----") Ohai::Log.debug(stderr_string.strip) Ohai::Log.debug("---- End #{args[:command]} STDERR ----") end args[:returns] ||= 0 args[:no_status_check] ||= false if status.exitstatus != args[:returns] and not args[:no_status_check] raise Ohai::Exceptions::Exec, "#{args[:command_string]} returned #{status.exitstatus}, expected #{args[:returns]}" else Ohai::Log.debug("Ran #{args[:command_string]} (#{args[:command]}) returned #{status.exitstatus}") end end return status, stdout_string, stderr_string end |
.shell_out(cmd) ⇒ Object
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# File 'lib/ohai/mixin/command.rb', line 31 def shell_out(cmd) m = Mixlib::ShellOut.new(cmd) m.run_command m end |
Instance Method Details
#run_command_unix(command, timeout) ⇒ Object Also known as: run_command_backend
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# File 'lib/ohai/mixin/command.rb', line 83 def run_command_unix(command, timeout) stderr_string, stdout_string, status = "", "", nil exec_processing_block = lambda do |pid, stdin, stdout, stderr| stdout_string, stderr_string = stdout.string.chomp, stderr.string.chomp end if timeout begin Timeout.timeout(timeout) do status = popen4(command, {}, &exec_processing_block) end rescue Timeout::Error => e Chef::Log.error("#{command} exceeded timeout #{timeout}") raise(e) end else status = popen4(command, {}, &exec_processing_block) end return status, stdout_string, stderr_string end |
#run_command_windows(command, timeout) ⇒ Object
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# File 'lib/ohai/mixin/command.rb', line 105 def run_command_windows(command, timeout) shellout_opts = {} shellout_opts[:timeout] = timeout if timeout m = Mixlib::ShellOut.new(command, shellout_opts) m.run_command [m.status, m.stdout, m.stderr] end |