feature: Added rrd step conversion script (#6081)

* feature: Added rrd step conversion script

* updated to support all for hostname

* update docs + code

* small updates as per murrant

doc/Support/1-Minute-Polling.md

@@ -1,5 +1,6 @@
 source: Support/1-Minute-Polling.md
 
+### Information
 We now have support for polling data at intervals to fit your needs.
 
 > Please be aware of the following:
@@ -13,3 +14,18 @@ To make the changes, please navigate to `/settings/sub=external/` within your We
 
   - Step is how often you want to insert data, so if you change to 1 minute polling then this should be 60.
   - Heartbeat is how long to wait for data before registering a null value, i.e 120 seconds.
+
+
+### Converting existing RRD files
+
+We provide a basic script to convert the default rrd files we generate to utilise your configured step and heartbeat 
+values. Please do ensure that you backup your RRD files before running this just in case. The script runs on a per 
+device basis or all devices at once.
+
+> The rrd files must be accessible from the server you run this script from.
+
+`./scripts/rrdstep.php`
+
+This will provide the help information. To run it for localhost just run:
+
+`./scripts/rrdstep.php -h localhost`

scripts/rrdstep.php

@@ -0,0 +1,85 @@
+#!/usr/bin/env php
+<?php
+/**
+ * rrdstep.php
+ *
+ * LibreNMS Script to convert rrd files from default 300 step to user defined
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @package    LibreNMS
+ * @link       http://librenms.org
+ * @copyright  2017 Neil Lathwood
+ * @author     Neil Lathwood <neil@lathwood.co.uk>
+ */
+
+$init_modules = array();
+require realpath(__DIR__ . '/..') . '/includes/init.php';
+
+$options = getopt('h:');
+
+$hostname = $options['h'] ?: '';
+
+if (empty($hostname)) {
+    echo "*********************************************************************\n";
+    echo "We highly suggest that you back up your rrd files before running this\n";
+    echo "*********************************************************************\n";
+    echo "-h <hostname or device id or all>  Device to process the rrd file for\n";
+    echo "\n";
+    exit;
+}
+
+if ($hostname !== 'all') {
+    $hostname = !ctype_digit($hostname) ? $hostname : gethostbyid($hostname);
+}
+
+if (empty($hostname)) {
+    echo "Invalid hostname or device id specified\n";
+    exit;
+}
+
+$step      = $config['rrd']['step'];
+$heartbeat = $config['rrd']['heartbeat'];
+$rrd_path  = $config['rrd_dir'];
+$rrdtool   = $config['rrdtool'];
+$tmp_path  = $config['temp_dir'];
+
+if ($hostname === 'all') {
+    $hostname = '*';
+}
+$files = glob($rrd_path . '/' . $hostname . '/*.rrd');
+
+$run = readline("Are you sure you want to run this command [N/y]: ");
+if (!($run == 'y' || $run == 'Y')) {
+    echo "Exiting....." . PHP_EOL;
+    exit;
+}
+
+foreach ($files as $file) {
+    $random = $tmp_path.'/'.mt_rand() . '.xml';
+    $tmp = explode('/', $file);
+    $rrd_file = array_pop($tmp);
+    echo "Converting $file: ";
+    $command = "$rrdtool dump $file > $random && 
+        sed -i 's/<step>300/<step>$step/' $random && 
+        sed -i 's/<minimal_heartbeat>600/<minimal_heartbeat>$heartbeat/' $random &&
+        $rrdtool restore -f $random $file &&
+        rm -f $random";
+    exec($command, $output, $code);
+    if ($code === 0) {
+        echo "[OK]\n";
+    } else {
+        echo "\033[FAIL]\n";
+    }
+}