CAF::Service

NAME

CAF::Service - Class for starting and stopping daemons in different platforms

SYNOPSIS

use CAF::Service;
my $srv = CAF::Service->new(['ntpd'], log => $self, %opts);
$srv->reload();
$srv->stop();
$srv->start();
$srv->restart();
$srv->condrestart();
$srv->stop_sleep_start();

Will do the right thing with SystemV Init scripts, Systemd units and Solaris’ svcadm.

DESCRIPTION

This class abstracts away the differences when operating with Daemons in different Unixes.

Private methods

  • _initialize

Initialize the process object. Arguments:

  • $services
Reference to a list of services to be handled.

It takes some extra optional arguments:

  • log
A CAF::Reporter object to log daemon activities to.
  • timeout

Maximum execution time, in seconds, for any service operations. If it’s too slow it will be killed. If not defined, the command won’t time out.

On Solaris it implies that svcadm actions are executed synchronously. After this timeout, the operation will continue in background, but will NOT mark the service as failed. For marking timed out services operations as failed, we have to edit the method definition, which is out of the scope of this method. See the man page for smf_method for more details.

On systemd-based systems, the timeout parameter is ignored. The correct way to handle timeouts in systemd is to store them in the unit file, which will ensure they are respected in any context that unit may be called.

  • sleep.
Used only in stop_sleep_start. Determines the number of seconds to sleep after stop before proceeding with start.
  • persistent
Used only in the Solaris variant of start and stop. Make the enabling or disabling of this service persist in subsequent reboots. Implies not passing the -t flag to svcadm.
  • recursive.
Used only in the Solaris variant of start and stop. Starts or stops all the dependencies for the given daemons, too.
  • synchronous

Used only in the Solaris variant of restart. Waits until all services have been restarted.

If no timeout was passed, it will wait forever.

…

Public methods

  • restart
Restarts the daemons.
  • start
Starts the daemons.
  • stop
Stops the daemons
  • reload
Reloads the daemons
  • stop_sleep_start
Stops the daemon, sleep, and then start the dameon again. Only when both stop and start are successful, return success.
  • os_flavour

Determine and return the OS flavour (/variant)

Current flavours are

  • linux_sysv
Linux OS with SysV int system
  • linux_systemd
Linux OS with systemd
  • solaris
Solaris OS

(All supported flavours are exported via @FLAVOURS.)

Private methods

  • __make_method

A generator for service methods, to be used in e.g. subclassing. In the example below we create a custom service class that supports e.g. ‘service myservice init’:

package MyService;

use CAF::Service qw(__make_method @FLAVOURS);
use parent qw(CAF::Service);

sub _initialize {
    my ($self, %opts) = @_;
    return $self->SUPER::_initialize(['myservice'], %opts);
}

my $method = 'init';
foreach my $flavour (@FLAVOURS) {
    no strict 'refs';
    *{"${method}_${flavour}"} = __make_method($method, $flavour);
    use strict 'refs';
}

1;

This class can than be used in the same way as CAF::Service

use MyService;
...
my $serv = MyService->new();
$serv->init();
...
$serv->reload();