uptime

// The time since boot of a Linux, by SSH. A reboot shows as a time since boot shorter than the threshold
// of "Recent reboot".
// Reads /proc/uptime with cat: the kernel writes it the same way on Alpine, Debian and Fedora,
// "350735.47 1374566.28", the seconds since boot then the idle time of all cores.
need('protocol:ssh');

output('uptime', 'number', array('label' => 'Time since boot', 'unit' => 'h'));

watch.below('rebooted', 'Recent reboot', 'uptime', array('warning' => 0.5));

$read = ssh.run('cat /proc/uptime');
$words = text.words($read['output']);
if (list.count($words) < 1 || !text.is_number($words[0])) {
    fail('misconfigured', 'No time since boot found in /proc/uptime', $read['output'] . $read['errors']);
}
value('uptime', number.round($words[0] / 3600, 2));