librenms-librenms/html/pages/device/edit/alerts.inc.php

<?php
if ($_POST['editing'])
{
  if ($_SESSION['userlevel'] > "7")
  {
    $override_sysContact_bool = mres($_POST['override_sysContact']);
    if (isset($_POST['sysContact'])) { $override_sysContact_string  = mres($_POST['sysContact']); }
    $disable_notify  = mres($_POST['disable_notify']);

    if ($override_sysContact_bool) { set_dev_attrib($device, 'override_sysContact_bool', '1'); } else { del_dev_attrib($device, 'override_sysContact_bool'); }
    if (isset($override_sysContact_string)) { set_dev_attrib($device, 'override_sysContact_string', $override_sysContact_string); };
    if ($disable_notify) { set_dev_attrib($device, 'disable_notify', '1'); } else { del_dev_attrib($device, 'disable_notify'); }

    $update_message = "Device alert settings updated.";
    $updated = 1;
  }
  else
  {
    include("includes/error-no-perm.inc.php");
  }
}

if ($updated && $update_message)
{
  print_message($update_message);
} elseif ($update_message) {
  print_error($update_message);
}

$override_sysContact_bool = get_dev_attrib($device,'override_sysContact_bool');
$override_sysContact_string = get_dev_attrib($device,'override_sysContact_string');
$disable_notify = get_dev_attrib($device,'disable_notify');
?>

<div class="row">
    <div class="col-md-12">
        <span id="message"></span>
    </div>
</div>

<h3>Alert settings</h3>

<form id="edit" name="edit" method="post" action="" role="form" class="form-horizontal">
  <input type="hidden" name="editing" value="yes">
  <div class="form-group">
    <label for="override_sysContact" class="col-sm-3 control-label">Override sysContact:</label>
    <div class="col-sm-6">
      <input onclick="edit.sysContact.disabled=!edit.override_sysContact.checked" type="checkbox" id="override_sysContact" name="override_sysContact"<?php if ($override_sysContact_bool) { echo(' checked="1"'); } ?> />
    </div>
  </div>
  <div class="form-group">
    <div class="col-sm-3">
    </div>
    <div class="col-sm-6">
      <input id="sysContact" class="form-control" name="sysContact" size="32"<?php if (!$override_sysContact_bool) { echo(' disabled="1"'); } ?> value="<?php echo($override_sysContact_string); ?>" />
    </div>
  </div>
  <div class="form-group">
    <label for="disable_notify" class="col-sm-3 control-label">Disable all alerting for this host: </label>
    <div class="col-sm-6">
      <input id="disable_notify" type="checkbox" name="disable_notify"<?php if ($disable_notify) { echo(' checked="1"'); } ?> />
    </div>
  </div>
  <button class="btn btn-default btn-sm" type="submit" name="Submit">Save</button>
</form>

<?php
require_once("includes/modal/new_alert_rule.inc.php");
?>
<button type="button" class="btn btn-primary btn-sm" data-toggle="modal" data-target="#create-alert" data-device_id="<?php echo $device['device_id'];?>">Create new alert rule</button>