erlexec
1.0.0
Autor Serge Aleynikov <Saleyn (at) Gmail.com>
Ejecutar y controlar los procesos de SO de Erlang/OTP.
Este proyecto implementa una aplicación Erlang con un programa de puerto C ++ que proporciona a los procesos de Erlang de peso ligero de control de grano fino sobre la ejecución de los procesos del sistema operativo.
Se admiten las siguientes características:
erlang:monitor/2 . Esta aplicación proporciona un control significativamente mejor sobre los procesos del sistema operativo que el comando erlang:open_port/2 incorporado con una opción {spawn, Command} , y realiza una limpieza adecuada del proceso de SO Child cuando el emulador sale.
La aplicación erlexec ha estado en uso de los sistemas Erlang y Elixir, y se considera estable.
Si encuentra útil este proyecto, done a:
12pt8TcoMWMkF6iY66VJQk95ntdN4pFihg0x268295486F258037CF53E504fcC1E67eba014218 Linux, Solaris, FreeBSD, OpenBSD, MacOS X
Ver https://hexdocs.pm/erlexec/readme.html
rebar.config { deps ,
[ % ...
{ erlexec , " ~> 2.0 " }
]}.*.app.src : { applications ,
[ kernel ,
stdlib ,
% ...
erlexec
]} defp deps do
[
# ...
{ :erlexec , "~> 2.0" }
]
end Asegúrese de tener barras de refuerzo o barras de refuerzo 3 instaladas localmente y el script de refuerzo está en la ruta.
Si está implementando la aplicación en Linux y desea aprovechar las tareas EXEC-puerto que se ejecuta con ID efectivas de usuario diferentes de la ID de usuario real que comenzó a EXEC-Port, ya sea que asegúrese de que la biblioteca LibCap-Dev [El] esté instalada o se asegure de que el usuario que ejecute el programa de puerto tenga derechos sudo .
Instrucciones de instalación específicas de libcap-devs del sistema operativo:
$ git clone [email protected]:saleyn/erlexec.git
$ make
# NOTE: for disabling optimized build of exec-port, do the following instead:
$ OPTIMIZE=0 make Por defecto, la implementación del programa de puertos utiliza poll(2) Llame para la demultiplexación de eventos. Si prefiere usar select(2) , establezca la siguiente variable de entorno:
$ USE_POLL=0 makeEl programa se distribuye bajo la licencia BSD.
Copyright (c) 2003 Serge Aleynikov
"
│ ┌─── razón
│ │pid1│ │pid2│ │pidn│ │ erlang pids de peso ligero asociados
│ └─── razón
│ ╲ │ ╱ │
│ ╲ │ ╱ │
│ ╲ │ ╱ (enlaces) │
│ ┌ especialmente
│ │ EXEC │ │ │ │ EXEC Aplicación que se ejecuta en Erlang VM
│ └ especialmente
│ Erlang VM │ │
"
│
"
│ Programa de puerto EXEC-PORT │ (proceso de sistema operativo separado)
"
╱ │ ╲
(tuberías opcionales de stdin/stdout/stderr)
╱ │ ╲
┌─── razón
│ospid1│ │ospid2│ │ospidn│ Procesos de OS de niños manejados
└─── razón
Consulte la descripción de los tipos en {@Link Exec: Exec_options ()}.
El programa exec-port requiere que se establezca la variable SHELL . Si está ejecutando Erlang dentro de un contenedor Docker, es posible que deba asegurarse de que SHELL esté correctamente configurado antes de iniciar el emulador.
exec admite varias opciones de depuración pasadas a exec:start/1 :
{debug, Level} - Enciende la verbosidad de depuración en el programa de puerto.verbose : enciende la verbosidad en el código de Erlang.valgrind : ejecuta EXEC debajo de la herramienta Valgrind, que debe instalarse en el sistema operativo. Esto genera un archivo local valgrind.YYYYMMDDhhmmss.log que contiene la salida de Valgrind. Si necesita personalizar las opciones de comando Valgrind, use {valgrind, "/path/to/valgrind Args ..."} . 1 > exec : start (). % Start the port program.
{ ok , < 0.32 . 0 > }
2 > { ok , _ , I } = exec : run_link ( " sleep 1000 " , []). % Run a shell command to sleep for 1000s.
{ ok , < 0.34 . 0 > , 23584 }
3 > exec : stop ( I ). % Kill the shell command.
ok % Note that this could also be accomplished
% by doing exec:stop(pid(0,34,0)).En Elixir:
iex ( 1 ) > :exec . start
{ :ok , #PID<0.112.0>}
iex ( 2 ) > :exec . run ( "echo ok" , [ :sync , :stdout ] )
{ :ok , [ stdout: [ "ok n " ] ] }
% % Clear environment with {env, [clear]} option:
10 > f ( Bin ), { ok , [{ stdout , [ Bin ]}]} = exec : run ( " env " , [ sync , stdout , { env , [ clear ]}]), p ( re : split ( Bin , << " n " >>)).
[<< " PWD=/home/... " >>,<< " SHLVL=0 " >>, << " _=/usr/bin/env " >>,<<>>]
ok
% % Clear env and add a "TEST" env variable:
11 > f ( Bin ), { ok , [{ stdout , [ Bin ]}]} = exec : run ( " env " , [ sync , stdout , { env , [ clear , { " TEST " , " xxx " }]}]), p ( re : split ( Bin , << " n " >>)).
[<< " PWD=/home/... " >>,<< " SHLVL=0 " >>, << " _=/usr/bin/env " >>,<< " TEST=xxx " >>,<<>>]
% % Unset an "EMU" env variable:
11 > f ( Bin ), { ok , [{ stdout , [ Bin ]}]} = exec : run ( " env " , [ sync , stdout , { env , [{ " EMU " , false }]}]), p ( re : split ( Bin , << " n " >>)).
[...]
ok Para poder usar esta función, el usuario actual debe tener los derechos sudo o el archivo exec-port debe ser propiedad de root y tener el bits Suid (use: chown root:root exec-port; chmod 4555 exec-port )::
$ ll priv/x86_64-unknown-linux-gnu/exec-port
-rwsr-xr-x 1 root root 777336 Dec 8 10:02 ./priv/x86_64-unknown-linux-gnu/exec-port Si el usuario efectivo no tiene derechos para acceder al programa exec-port en el directorio del usuario real, entonces el exec-port se puede copiar en alguna ubicación compartida, que se especificará al inicio utilizando {portexe, "/path/to/exec-port"} .
$ cp $( find . - name exec - port ) / tmp
$ chmod 755 / tmp / exec - port
$ whoami
serge
$ erl
1 > exec : start ([{ user , " wheel " }, { portexe , " /tmp/exec-port " }]). % Start the port program as effective user "wheel".
{ ok , < 0.32 . 0 > }
$ ps haxo user , comm | grep exec - port
wheel exec - port Para poder usar esta función, el usuario actual debe tener los derechos sudo o el archivo exec-port debe tener el Bit SUID establecido, y el archivo exec-port debe tener las capacidades establecidas como se describe en la sección "Build" anterior.
El programa de puerto inicialmente se iniciará como root , y luego cambiará el usuario efectivo a {user, User} y establecerá capacidades de proceso a cap_setuid,cap_kill,cap_sys_nice . Después de eso, permitirá ejecutar programas infantiles bajo usuarios efectivos que figuran en la opción {limit_users, Users} .
$ whoami
serge
$ erl
1 > Opts = [ root , { user , " wheel " }, { limit_users , [ " alex " , " guest " ]}],
2 > exec : start ( Opts ). % Start the port program as effective user "wheel"
% and allow it to execute commands as "alex" or "guest".
{ ok , < 0.32 . 0 > }
3 > exec : run ( " whoami " , [ sync , stdout , { user , " alex " }]). % Command is executed under effective user "alex"
{ ok ,[{ stdout ,[<< " alex n " >>]}]}
$ ps haxo user , comm | grep exec - port
wheel exec - portMientras ejecuta el programa de puerto como raíz, está muy desanimado, ya que abre un orificio de seguridad que brinda a los usuarios la capacidad de dañar el sistema, para aquellos que pueden necesitar tal opción, aquí es cómo hacerlo (¡continúe con su propio riesgo!).
NOTA: En este caso, exec usaría sudo exec-port para ejecutarlo como root o el exec-port debe tener el conjunto de bits Suid (4555) y ser propiedad de root . La otra alternativa (¡peligrosa y firmemente desanimada!) Es ejecutar erl como root :
$ whoami
serge
# Make sure the exec - port can run as root :
$ sudo _build / default / lib / erlexec / priv /*/ exec - port -- whoami
root
$ erl
1 > exec : start ([ root , { user , " root " }, { limit_users , [ " root " ]}]).
2 > exec : run ( " whoami " , [ sync , stdout ]).
{ ok , [{ stdout , [<< " root n " >>]}]}
$ ps haxo user , comm | grep exec - port
root exec - portTenga en cuenta que matar un proceso se puede lograr ejecutando el comando Kill (3) en un caparazón externo, o ejecutando Exec: Kill/2.
1 > f ( I ), { ok , _ , I } = exec : run_link ( " sleep 1000 " , []).
{ ok , < 0.37 . 0 > , 2350 }
2 > exec : kill ( I , 15 ).
ok
** exception error : { exit_status , 15 } % Our shell died because we linked to the
% killed shell process via exec:run_link/2.
3 > exec : status ( 15 ). % Examine the exit status.
{ signal , 15 , false } % The program got SIGTERM signal and produced
% no core file. 1 > exec : start_link ([]).
{ ok , < 0.35 . 0 > }
2 > exec : run_link ( " sleep 1 " , [{ success_exit_code , 0 }, sync ]).
{ ok ,[]}
3 > exec : run ( " sleep 1 " , [{ success_exit_code , 1 }, sync ]).
{ error ,[{ exit_status , 1 }]} % Note that the command returns exit code 1 7 > f ( I ), { ok , _ , I } = exec : run_link ( " for i in 1 2 3; do echo " Test$i " ; done " ,
[{ stdout , " /tmp/output " }]).
8 > io : format ( " ~s " , [ binary_to_list ( element ( 2 , file : read_file ( " /tmp/output " )))]),
file : delete ( " /tmp/output " ).
Test1
Test2
Test3
ok 9 > exec : run ( " echo Test " , [{ stdout , print }]).
{ ok , < 0.119 . 0 > , 29651 }
Got stdout from 29651 : << " Test n " >>
10 > exec : run ( " for i in 1 2 3; do sleep 1; echo " Iter$i " ; done " ,
[{ stdout , fun ( S , OsPid , D ) -> io : format ( " Got ~w from ~w : ~p n " , [ S , OsPid , D ]) end }]).
{ ok , < 0.121 . 0 > , 29652 }
Got stdout from 29652 : << " Iter1 n " >>
Got stdout from 29652 : << " Iter2 n " >>
Got stdout from 29652 : << " Iter3 n " >>
% Note that stdout/stderr options are equivanet to {stdout, self()}, {stderr, self()}
11 > exec : run ( " echo Hello World!; echo ERR!! 1>&2 " , [ stdout , stderr ]).
{ ok , < 0.244 . 0 > , 18382 }
12 > flush ().
Shell got { stdout , 18382 ,<< " Hello World! n " >>}
Shell got { stderr , 18382 ,<< " ERR!! n " >>}
ok 13 > exec : run ( " for i in 1 2 3; do echo TEST$i; done " ,
[{ stdout , " /tmp/out " , [ append , { mode , 8#600 }]}, sync ]),
file : read_file ( " /tmp/out " ).
{ ok ,<< " TEST1 n TEST2 n TEST3 n " >>}
14 > exec : run ( " echo Test4; done " , [{ stdout , " /tmp/out " , [ append , { mode , 8#600 }]}, sync ]),
file : read_file ( " /tmp/out " ).
{ ok ,<< " TEST1 n TEST2 n TEST3 n Test4 n " >>}
15 > file : delete ( " /tmp/out " ). > f ( I ), f ( P ), { ok , P , I } = exec : run ( " echo ok " , [{ stdout , self ()}, monitor ]).
{ ok , < 0.263 . 0 > , 18950 }
16 > flush ().
Shell got { stdout , 18950 ,<< " ok n " >>}
Shell got { 'DOWN' , 18950 , process , < 0.263 . 0 > , normal }
okEste comando permite instruir a Erlexec que comience a monitorear el proceso del sistema operativo y notifique a Erlang cuándo sale el proceso. También puede enviar señales al proceso y matarlo.
% Start an externally managed OS process and retrieve its OS PID:
17 > spawn ( fun () -> os : cmd ( " echo $$ > /tmp/pid; sleep 15 " ) end ).
< 0.330 . 0 >
18 > f ( P ), P = list_to_integer ( lists : reverse ( tl ( lists : reverse ( binary_to_list ( element ( 2 ,
file : read_file ( " /tmp/pid " ))))))).
19355
% Manage the process and get notified by a monitor when it exits:
19 > exec : manage ( P , [ monitor ]).
{ ok , < 0.334 . 0 > , 19355 }
% Wait for monitor notification
20 > f ( M ), receive M -> M end .
{ 'DOWN' , 19355 , process , < 0.334 . 0 > ,{ exit_status , 10 }}
ok
21 > file : delete ( " /tmp/pid " ).
ok % Execute an OS process (script) that blocks SIGTERM with custom kill timeout, and monitor
22 > f ( I ), { ok , _ , I } = exec : run ( " trap '' SIGTERM; sleep 30 " , [{ kill_timeout , 3 }, monitor ]).
{ ok , < 0.399 . 0 > , 26347 }
% Attempt to stop the OS process
23 > exec : stop ( I ).
ok
% Wait for its completion
24 > f ( M ), receive M -> M after 10000 -> timeout end .
{ 'DOWN' , 26347 , process , < 0.403 . 0 > , normal } % Execute an OS process (script) that blocks SIGTERM, and uses a custom kill command,
% which kills it with a SIGINT. Add a monitor so that we can wait for process exit
% notification. Note the use of the special environment variable "CHILD_PID" by the
% kill command. This environment variable is set by the port program before invoking
% the kill command:
2 > f ( I ), { ok , _ , I } = exec : run ( " trap '' SIGTERM; sleep 30 " , [{ kill , " kill -n 2 ${CHILD_PID} " },
{ kill_timeout , 2 }, monitor ]).
{ ok , < 0.399 . 0 > , 26347 }
% Try to kill by SIGTERM. This does nothing, since the process is blocking SIGTERM:
3 > exec : kill ( I , sigterm ), f ( M ), receive M -> M after 0 -> timeout end .
timeout
% Attempt to stop the OS process
4 > exec : stop ( I ).
ok
% Wait for its completion
5 > f ( M ), receive M -> M after 1000 -> timeout end .
{ 'DOWN' , 26347 , process , < 0.403 . 0 > , normal } % Execute an OS process (script) that reads STDIN and echoes it back to Erlang
25 > f ( I ), { ok , _ , I } = exec : run ( " read x; echo " Got: $x " " , [ stdin , stdout , monitor ]).
{ ok , < 0.427 . 0 > , 26431 }
% Send the OS process some data via its stdin
26 > exec : send ( I , << " Test data n " >>).
ok
% Get the response written to processes stdout
27 > f ( M ), receive M -> M after 10000 -> timeout end .
{ stdout , 26431 ,<< " Got: Test data n " >>}
% Confirm that the process exited
28 > f ( M ), receive M -> M after 10000 -> timeout end .
{ 'DOWN' , 26431 , process , < 0.427 . 0 > , normal } A veces, un proceso de SO infantil generado que recibe la entrada Stdin debe detectar el final de la entrada para procesar los datos entrantes. Cuando los comandos de tuberías (por ejemplo cat file | tac ) esto se maneja detectando el EOF mediante el extremo de lectura de la tubería cuando se cierra el extremo de escritura de la tubería. En erlexec esto se maneja enviando explícitamente el átomo eof al proceso del sistema operativo que escucha a Stdin:
2 > Watcher = spawn ( fun F () -> receive Msg -> io : format ( " Got: ~p n " , [ Msg ]), F () after 60000 -> ok end end ).
< 0.112 . 0 >
3 > f ( Pid ), f ( OsPid ), { ok , Pid , OsPid } = exec : run ( " tac " , [ stdin , { stdout , Watcher }, { stderr , Watcher }]).
{ ok , < 0.114 . 0 > , 26143 }
4 > exec : send ( Pid , << " foo n " >>).
ok
5 > exec : send ( Pid , << " bar n " >>).
ok
6 > exec : send ( Pid , << " baz n " >>).
ok
7 > exec : send ( Pid , eof ). % % <--- sending the EOF command to the STDIN
ok
Got : { stdout , 26143 ,<< " baz n bar n foo n " >>} % Execute an shell script that blocks for 1 second and return its termination code
29 > exec : run ( " sleep 1; echo Test " , [ sync ]).
% By default all I/O is redirected to /dev/null, so no output is captured
{ ok ,[]}
% 'stdout' option instructs the port program to capture stdout and return it to caller
30 > exec : run ( " sleep 1; echo Test " , [ stdout , sync ]).
{ ok ,[{ stdout , [<< " Test n " >>]}]}
% Execute a non-existing command
31 > exec : run ( " echo1 Test " , [ sync , stdout , stderr ]).
{ error ,[{ exit_status , 32512 },
{ stderr ,[<< " /bin/bash: echo1: command not found n " >>]}]}
% Capture stdout/stderr of the executed command
32 > exec : run ( " echo Test; echo Err 1>&2 " , [ sync , stdout , stderr ]).
{ ok ,[{ stdout ,[<< " Test n " >>]},{ stderr ,[<< " Err n " >>]}]}
% Redirect stderr to stdout
33 > exec : run ( " echo Test 1>&2 " , [{ stderr , stdout }, stdout , sync ]).
{ ok , [{ stdout , [<< " Test n " >>]}]} % Execute a command by an OS shell interpreter
34 > exec : run ( " echo ok " , [ sync , stdout ]).
{ ok , [{ stdout , [<< " ok n " >>]}]}
% Execute an executable without a shell (note that in this case
% the full path to the executable is required):
35 > exec : run ([ " /bin/echo " , " ok " ], [ sync , stdout ])).
{ ok , [{ stdout , [<< " ok n " >>]}]}
% Execute a shell with custom options
36 > exec : run ([ " /bin/bash " , " -c " , " echo ok " ], [ sync , stdout ])).
{ ok , [{ stdout , [<< " ok n " >>]}]} % Execute a command without a pty
37 > exec : run ( " echo hello " , [ sync , stdout ]).
{ ok , [{ stdout ,[<< " hello n " >>]}]}
% Execute a command with a pty
38 > exec : run ( " echo hello " , [ sync , stdout , pty ]).
{ ok ,[{ stdout ,[<< " hello " >>,<< " rn " >>]}]}
% Execute a command with pty echo
39 > { ok , P0 , I0 } = exec : run ( " cat " , [ stdin , stdout , { stderr , stdout }, pty , pty_echo ]).
{ ok , < 0.162 . 0 > , 17086 }
40 > exec : send ( I0 , << " hello " >>).
ok
41 > flush ().
Shell got { stdout , 17086 ,<< " hello " >>}
ok
42 > exec : send ( I0 , << " n " >>).
ok
43 > flush ().
Shell got { stdout , 17086 ,<< " rn " >>}
Shell got { stdout , 17086 ,<< " hello rn " >>}
ok
44 > exec : send ( I , << 3 >>).
ok
45 > flush ().
Shell got { stdout , 17086 ,<< " ^C " >>}
Shell got { 'DOWN' , 17086 , process , < 0.162 . 0 > ,{ exit_status , 2 }}
ok
% Execute a command with custom pty options
46 > { ok , P1 , I1 } = exec : run ( " cat " , [ stdin , stdout , { stderr , stdout }, { pty , [{ vintr , 2 }]}, monitor ]).
{ ok , < 0.199 . 0 > , 16662 }
47 > exec : send ( I1 , << 3 >>).
ok
48 > flush ().
ok
49 > exec : send ( I1 , << 2 >>).
ok
50 > flush ().
Shell got { 'DOWN' , 16662 , process , < 0.199 . 0 > ,{ exit_status , 2 }}
ok % In the following scenario the process P0 will create a new process group
% equal to the OS pid of that process (value = GID). The next two commands
% are assigned to the same process group GID. As soon as the P0 process exits
% P1 and P2 will also get terminated by signal 15 (SIGTERM):
51 > { ok , P2 , GID } = exec : run ( " sleep 10 " , [{ group , 0 }, kill_group ]).
{ ok , < 0.37 . 0 > , 25306 }
52 > { ok , P3 , _ } = exec : run ( " sleep 15 " , [{ group , GID }, monitor ]).
{ ok , < 0.39 . 0 > , 25307 }
53 > { ok , P4 , _ } = exec : run ( " sleep 15 " , [{ group , GID }, monitor ]).
{ ok , < 0.41 . 0 > , 25308 }
54 > flush ().
Shell got { 'DOWN' , 25307 , process , < 0.39 . 0 > ,{ exit_status , 15 }}
Shell got { 'DOWN' , 25308 , process , < 0.41 . 0 > ,{ exit_status , 15 }}
ok
