Shambhu Lal Verma vermaslal

## sysctl.conf
The new tweaks, placed in /etc/sysctl.conf (CentOS) and then reload with “sysctl -p” :

net.core.rmem_max = 33554432
net.core.wmem_max = 33554432
net.ipv4.tcp_rmem = 4096 16384 33554432
net.ipv4.tcp_wmem = 4096 16384 33554432
net.ipv4.tcp_mem = 786432 1048576 26777216
net.ipv4.tcp_max_tw_buckets = 360000
net.core.netdev_max_backlog = 2500
vm.min_free_kbytes = 65536

## test.js
/**
 * Modify the parts you need to get it working.
 */

var should = require('should');
var request = require('../node_modules/request');
var io = require('socket.io-client');

var serverUrl = 'http://localhost';

## README.MD

      
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              Last active
              October 1, 2021 02:38
            
              
                Drop Root Privileges in Node.js when using port <1024
              
          
    A common use for Node.js is to build web applications. Usually, we want these applications to listen on port 80. As a security precaution, most OS’s require root privileges for this to happen (e.g. OS X, Linux, BSD). To run a Node application this way, we need to do the following:
sudo node server.js

Then, the application runs as root for the rest of the session. There are potential security risks to this, though. What if there is a vulnerability in your application and a hacker starts controlling your app and doing naughty things with it? Thankfully, we can drop the user account running our process to a less secured user, such as our normal account. There are two methods on the process global which can handle this for us, .setgid() and .setuid().
Here’s a working example of this in action. We want to run this code AFTER we bind to port 80, so we run the code in a callback:

  
## nodejs-ubuntu-bind-port-80.md

      
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                vermaslal
                / nodejs-ubuntu-bind-port-80.md
            
            
              Created
              April 2, 2017 18:07
                — forked from guifromrio/nodejs-ubuntu-bind-port-80.md
            
              
                Allow Node.js to bind to privileged ports without root access on Ubuntu
              
          
    How to: Allow Node to bind to port 80 without sudo

TL;DR

Only do this if you understand the consequences: all node programs will be able to bind on ports < 1024
sudo setcap 'cap_net_bind_service=+ep' /usr/local/bin/node

Important: your node location may vary. Use which node to find it, or use it directly in the command:

  
## amqplib-delayed-message.js
/**
 * Install and enable the rabbitmq_delayed_message_exchange plugin as described by Alvaro Videla in this blogpost:
 * https://www.rabbitmq.com/blog/2015/04/16/scheduling-messages-with-rabbitmq/
 */
const amqp = require('amqplib');
const exchange = 'yourExchangeName';
const queue = 'yourQueueName';
const queueBinding = 'yourQueueBindingName';

// Message consumer

## Linux Static IP
## Configure eth0
#
# vi /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE="eth0"
NM_CONTROLLED="yes"
ONBOOT=yes
HWADDR=A4:BA:DB:37:F1:04
TYPE=Ethernet
BOOTPROTO=static

## sysctl.conf
# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled.  See sysctl(8) and
# sysctl.conf(5) for more details.

# Controls source route verification
net.ipv4.conf.default.rp_filter = 1

# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0

## nonBlockingForEach.js
/**
 * Allow other processes to execute while iterating over
 * an array. Useful for large arrays, or long-running processing
 *
 * @param {Function} fn    iterator fed each element of the array.
 * @param {Function} next  executed when done
 */
Array.prototype.nonBlockingForEach = function(fn, next) {
  var arr = this;
  var i = 0;

## jquery.alterclass.js
/**
 * jQuery alterClass plugin
 *
 * Remove element classes with wildcard matching. Optionally add classes:
 *   $( '#foo' ).alterClass( 'foo-* bar-*', 'foobar' )
 *
 * Copyright (c) 2011 Pete Boere (the-echoplex.net)
 * Free under terms of the MIT license: http://www.opensource.org/licenses/mit-license.php
 *
 */

## numberRestriction.html
<!DOCTYPE html>
<html>
    <head>

    </head>
    <body>
        <div>
            <input type="text" class="numeric"/><br>
            <input type="text" class="numeric"/>
        </div>
	The new tweaks, placed in /etc/sysctl.conf (CentOS) and then reload with “sysctl -p” :

	net.core.rmem_max = 33554432
	net.core.wmem_max = 33554432
	net.ipv4.tcp_rmem = 4096 16384 33554432
	net.ipv4.tcp_wmem = 4096 16384 33554432
	net.ipv4.tcp_mem = 786432 1048576 26777216
	net.ipv4.tcp_max_tw_buckets = 360000
	net.core.netdev_max_backlog = 2500
	vm.min_free_kbytes = 65536
	/**
	* Modify the parts you need to get it working.
	*/

	var should = require('should');
	var request = require('../node_modules/request');
	var io = require('socket.io-client');

	var serverUrl = 'http://localhost';
	/**
	* Install and enable the rabbitmq_delayed_message_exchange plugin as described by Alvaro Videla in this blogpost:
	* https://www.rabbitmq.com/blog/2015/04/16/scheduling-messages-with-rabbitmq/
	*/
	const amqp = require('amqplib');
	const exchange = 'yourExchangeName';
	const queue = 'yourQueueName';
	const queueBinding = 'yourQueueBindingName';

	// Message consumer
	## Configure eth0
	#
	# vi /etc/sysconfig/network-scripts/ifcfg-eth0

	DEVICE="eth0"
	NM_CONTROLLED="yes"
	ONBOOT=yes
	HWADDR=A4:BA:DB:37:F1:04
	TYPE=Ethernet
	BOOTPROTO=static
	# Kernel sysctl configuration file for Red Hat Linux
	#
	# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
	# sysctl.conf(5) for more details.

	# Controls source route verification
	net.ipv4.conf.default.rp_filter = 1

	# Do not accept source routing
	net.ipv4.conf.default.accept_source_route = 0
	/**
	* Allow other processes to execute while iterating over
	* an array. Useful for large arrays, or long-running processing
	*
	* @param {Function} fn iterator fed each element of the array.
	* @param {Function} next executed when done
	*/
	Array.prototype.nonBlockingForEach = function(fn, next) {
	var arr = this;
	var i = 0;
	/**
	* jQuery alterClass plugin
	*
	* Remove element classes with wildcard matching. Optionally add classes:
	* $( '#foo' ).alterClass( 'foo-* bar-*', 'foobar' )
	*
	* Copyright (c) 2011 Pete Boere (the-echoplex.net)
	* Free under terms of the MIT license: http://www.opensource.org/licenses/mit-license.php
	*
	*/
	<!DOCTYPE html>
	<html>
	<head>

	</head>
	<body>
	<div>
	<input type="text" class="numeric"/><br>
	<input type="text" class="numeric"/>
	</div>