oracular (3) Mojo::IOLoop::ReadWriteProcess::Container.3pm.gz
NAME
Mojo::IOLoop::ReadWriteProcess::Container - (kinda) Pure Perl containers.
SYNOPSIS
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $container = container(
pid_isolation => 1, # Best-effort, as depends on where you run it (you need CAP_SYS_ADMIN)
subreaper => 1,
group => "my_org",
name => "my_process",
process => process(
sub {
# Exec, fork ..
process(sub { warn "\o/"; sleep 42; })->start;
process(sub { warn "\o/"; sleep 42; })->start;
process(
sub {
process(
sub {
process(sub { warn "\o/"; sleep 42; })->start;
warn "\o/";
sleep 400;
warn "\o/";
})->start;
warn "Hey";
sleep 42;
warn "\o/";
})->start;
sleep 42;
}
)->separate_err(0));
$container->start();
$container->is_running;
$container->stop;
my @procs = $container->cgroups->first->processes;
$container->cgroups->first->pid->max(300);
$container->process->on(stop => sub { print "Main container process stopped!" });
DESCRIPTION
Mojo::IOLoop::ReadWriteProcess::Container ties anonymous functions or a Mojo::IOLoop::ReadWriteProcess
object to different sets of Mojo::IOLoop::ReadWriteProcess::CGroup implementations.
When the "pid_isolation" attribute is set, it needs special permissions (CAP_SYS_ADMIN capabilities).
This module uses features that are only available on Linux, and requires cgroups and capability
(CAP_SYS_ADMIN) for unshare syscalls to achieve pid isolation.
EVENTS
Mojo::IOLoop::ReadWriteProcess inherits all events from Mojo::EventEmitter and can emit the following new
ones.
start
$container->on(start => sub {
my ($process) = @_;
...
});
Emitted when the container starts.
stop
$container->on(stop => sub {
my ($container) = @_;
...
});
Emitted when the container stops.
process_error
$container->on(container_error => sub {
my ($e) = @_;
my @errors = @{$e};
});
Emitted when the container produce errors.
METHODS
Mojo::IOLoop::ReadWriteProcess::Container inherits all methods from Mojo::EventEmitter and implements the
following new ones.
start
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $c = container( name=>"test", process => sub { print "Hello!" });
$c->start();
Starts the container, it's main process is a Mojo::IOLoop::ReadWriteProcess, contained in the "process()"
attribute. On stop it will terminate every process included in the cgroups attribute.
is_running
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $c = container( name=>"test", process => sub { print "Hello!" });
$c->is_running();
Returns 1 if the container is running.
stop
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $c = container( name=>"test", process => sub { print "Hello!" })->start;
$c->stop();
Stops the container and kill all the processes belonging to the cgroup. It also registers all the
unknown processes to the current Mojo::IOLoop::ReadWriteProcess::Session.
wait_stop
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $c = container( name=>"test", process => sub { print "Hello!" })->start;
$c->wait_stop();
Wait before stopping the container.
wait
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $c = container( name=>"test", process => sub { print "Hello!" })->start;
$c->wait();
Wait the container to stop
migrate_process
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $c = container( name=>"test", process => sub { print "Hello!" })->start;
$c->migrate_process(42);
Migrate the given process to the container cgroup.
ATTRIBUTES
Mojo::IOLoop::ReadWriteProcess::Container inherits all attributes from Mojo::EventEmitter and implements
the following new ones.
name
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
use Mojo::IOLoop::ReadWriteProcess::CGroup qw(cgroupv1);
use Mojo::Collection 'c';
my $container = container( name => "test", process => sub { print "Hello!" } );
$container->session->on(register => sub { ... });
$container->start();
Sets the container name. It creates in the indicated (or default) cgroups a sub-tree with the container
name.
This means that cgroups settings can be done also outside of the container object:
use Mojo::IOLoop::ReadWriteProcess::CGroup qw(cgroupv1);
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
my $container = container( name => "test", process => sub { print "Hello!" } );
cgroupv1->from($continer->cgroups->first->_group)->pid->max(100);
As cgroups are represented by path, you can set options directly from controllers objects that are
pointing to the same cgroup slice.
group
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
use Mojo::IOLoop::ReadWriteProcess::CGroup qw(cgroupv2);
use Mojo::Collection 'c';
my $container = container( name => "bar", group => "foo", process => sub { print "Hello!" } );
my $container2 = container( name => "bar2", group => "foo", process => sub { print "Hello!" } );
$container->start();
$container2->start();
my $group_cgroup = cgroupv2->from($container2->cgroups->first->parent);
$group_cgroup->pid->max(200);
Sets the container group. If containers are sharing the same group they will inherit the same CGroup
parent path, in such way it is possible to create controllers pointing to it and set specific options for
the whole group.
pid_isolation
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
use Mojo::IOLoop::ReadWriteProcess::CGroup qw(cgroupv1);
use Mojo::Collection 'c';
my $container = container( pid_isolation => 1, process => sub { print "Hello!" } );
$container->session->on(register => sub { ... });
$container->start();
If set, the process will see itself as PID 1. It needs CAP_SYS_ADMIN capabilities set on the executable
(or run as root).
pre_migrate
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $container = container( pre_migrate => 1, process => sub { print "Hello!" } );
$container->session->on(register => sub { ... });
$container->start();
If set, the process will migrate itself into the cgroup.
clean_cgroup
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $container = container( clean_cgroup => 1, process => sub { print "Hello!" });
$container->session->on(register => sub { ... });
$container->start();
If set, attempts to destroy the cgroup after the process terminated its execution.
subreaper
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $c = container(subreaper => 1, name=>"test", process => sub { print "Hello!" });
$c->start();
Enable subreaper mode inside the child process.
process
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $c = container(process => sub { print "Hello!" });
my $c = container(process => sub { print "Hello!" });
$c->start();
The process to run. It can be an anonymous function or a Mojo::IOLoop::ReadWriteProcess object.
namespace
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $c = container(process => sub { print "Hello!" });
$c->namespace->unshare(0); # All
$c->start();
Set/Return Mojo::IOLoop::ReadWriteProcess::Namespace object. It's main use is to invoke syscalls.
session
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
my $c = container(process => process(sub { print "Hello!" }));
$c->session->on(register => sub { ... });
$c->start();
Returns/Set the Mojo::IOLoop::ReadWriteProcess::Session singleton object.
unshare
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
use Mojo::IOLoop::ReadWriteProcess::Namespace qw( CLONE_NEWPID CLONE_NEWNS );
my $c = container( unshare=> CLONE_NEWPID | CLONE_NEWNS, process => sub { print "Hello!" } );
$c->session->on(register => sub { ... });
$c->start();
Returns/Set the unshare syscall options. See man unshare(2) for further documentation.
cgroups
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
use Mojo::IOLoop::ReadWriteProcess::CGroup qw(cgroupv1);
use Mojo::Collection 'c';
my $container = container(process => sub { print "Hello!" });
$container->cgroups( c(cgroupv1(controller => 'pids'), cgroupv1(controller => 'memory')) );
$container->session->on(register => sub { ... });
$container->start();
Returns/Set a Mojo::Collection collection of CGroups where the process should belong to. If used with a
single CGroup, you don't need to pass the Mojo::Collection object:
use Mojo::IOLoop::ReadWriteProcess::Container qw(container);
use Mojo::IOLoop::ReadWriteProcess qw(process);
use Mojo::IOLoop::ReadWriteProcess::CGroup qw(cgroupv1);
use Mojo::Collection 'c';
my $container = container(cgroups=> cgroupv1(controller => 'pids'), process => sub { print "Hello!" });
$container->session->on(register => sub { ... });
$container->start();
DEBUGGING
You can set the MOJO_EVENTEMITTER_DEBUG environment variable to get some advanced diagnostics information
printed to STDERR.
MOJO_EVENTEMITTER_DEBUG=1
Also, you can set MOJO_PROCESS_DEBUG environment variable to get diagnostics about the process execution.
MOJO_PROCESS_DEBUG=1
LICENSE
Copyright (C) Ettore Di Giacinto.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl
itself.
AUTHOR
Ettore Di Giacinto <edigiacinto@suse.com>