#!/usr/bin/php
<?php

/**
 * This script sets up a proxy based on an Amazon EC2 instance. It starts an
 * Amazon EC2 instance, installs TinyProxy and sets up an SSH tunnel to the 
 * machine.
 * 
 *                                   !!!
 *        !!!  NOTE: This script needs configuration. See below.  !!!
 *                                   !!!
 * 
 * USAGE             Make executable, then use like: $ ec2-proxy (start|stop)
 * REQUIREMENTS      - Amazon AWS account, X.509 certificate, EC2 private key
 *                   - Amazon API tools installed (ec2-api-tools)
 *
 * AUTHOR            Philipp C. Heckel
 * WEBSITE           http://blog.philippheckel.com/2012/06/15/script-your-us-proxy-server-in-two-minutes-using-amazon-ec2/
 * SCRIPT VERSION    Version 1 (June 2012)
 */


/// CONFIG /////////////////////////////////////////////////////////////////////

// Minimum setup (MUST BE CONFIGURED !!)
$SETUP_DONE    = false;                        // Set this to 'true' to enable the script
$PRIVATE_KEY   = "/your/private/key.pem";      // Private key for the region of the AMI below; download from AWS console
$KEYPAIR       = "NAME_OF_YOUR_KEYPAIR";       // Name of the private key for the region of the AMI below; download from 
                                               // AWS Account page: https://aws-portal.amazon.com/gp/aws/securityCredentials

// AMI options
$AMI           = "ami-ac9943c5";               // AMI name; default value is 'ami-ac9943c5', Ubuntu 12.04 32-bit EBS, micro
                                               // More Ubuntu AMIs at: http://uec-images.ubuntu.com/releases/
$PARAMS        = "--instance-type t1.micro";   // Additional params for the 'ec2-run-instances' command.
$LOGIN         = "ubuntu";                     // SSH login name for the above AMI image (for Ubuntu: 'ubuntu')

// Other options
$LOCAL_PORT    = 8888;                         // Port of the local SOCKS proxy (connect your browser to localhost:$LOCAL_PORT)



/// MAIN SCRIPT /////////////////////////////////////////////////////////////////

if (!$SETUP_DONE) {
	die("ERROR: Please configure the script before starting and set \$SETUP_DONE to 'true'.\n");
}

// Wrong usage, show help
if (count($argv) == 1) {
	showUsage();
}

// OPTION 'start'
if ($argv[1] == "start") {
	$machine = findInstance();

	// Not running
	if (!$machine) {
		// Do run via 'ec2-run-instances' and parse output for INSTANCE
		echo "[".date("H:i:s")."] Launching instance of AMI $AMI ... ";
		$out = `ec2-run-instances $AMI -k $KEYPAIR $PARAMS`;
		
		if (!preg_match("/INSTANCE	(\S+)/s",$out,$m)) {
			die("Invalid output from ec2-run-instances command:\n$out");
		}

		$instance = $m[1];
		echo "Launched instance $instance\n";

		// Run 'ec2-describe-instances' until we're ready
		echo "[".date("H:i:s")."] Waiting until ready ...";

		while (!($machine = findInstance($instance,true))) {
			echo ".";
		}
			
		echo " Running at {$machine['dns']}\n";		
	}
	
	// Test SSH by trying to login repeatedly with the private key
	// and writing OKAY on the console. Then parse the output for the OKAY
	echo "[".date("H:i:s")."] Testing SSH ...";
	while (true) {
		sleep(1);
		$out = `ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no $LOGIN@{$machine['dns']} -i $PRIVATE_KEY echo OKAY 2>&1`;
		echo ".";	
		
		if (preg_match("/OKAY/s",$out)) {
			break;
		}			
	}
	echo " ok.\n";	

	// Install the TinyProxy software. No further installation/setup needed!
	// Parse the output of 'apt-get' for 'Now installed'/...
	echo "[".date("H:i:s")."] Installing TinyProxy via SSH ... ";
	
	$out = `ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no $LOGIN@{$machine['dns']} -i $PRIVATE_KEY sudo apt-get install tinyproxy 2>&1`;
	if (preg_match("/Starting tinyproxy: tinyproxy./s",$out)) {
		echo "Now installed.\n";
	}
	else if (preg_match("/tinyproxy is already the newest version./s",$out)) {
		echo "Already installed.\n";
	}
	else {
		die("Unknown output. ABORTING.\n$out\n");
	}
				
	// Open SSH tunnel in the background
	echo "[".date("H:i:s")."] Starting SSH Tunnel to Proxy at localhost:$LOCAL_PORT ... ";
	echo `ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no $LOGIN@{$machine['dns']} -i $PRIVATE_KEY -L $LOCAL_PORT:localhost:8888 -N >/dev/null 2>&1 &`;
	echo "started.\n";
		
	// Test proxy by locally 'wget'ing the Google website via the proxy
	echo "[".date("H:i:s")."] Testing proxy localhost:$LOCAL_PORT ...";
	while (true) {
		$out = `http_proxy=http://localhost:$LOCAL_PORT wget -O /dev/null http://www.google.com/ 2>&1`;
		echo ".";	
		
		if (!preg_match("/Connection refused/s",$out)) {
			 break;
		}			
		
		sleep(1);		
	}
	
	echo " works!\n";	
}

// OPTION 'stop'
else if ($argv[1] == "stop") {
	$instance = findInstance();
	
	// Not running
	if (!$instance) {
		exit;
	}

	// Running: Now call 'ec2-terminate-instances'
	echo "[".date("H:i:s")."] Terminating instance {$instance['instance']} ... ";
	
	$out = `ec2-terminate-instances {$instance['instance']}`;
	if (preg_match("/{$instance['instance']}	running	shutting-down/s",$out)) {
		echo "Shutting down.\n";
	}		
	else {
		echo "Unknown status.\n$out";
	}
}

// OPTION 'status'
else if ($argv[1] == "status") {
	$instance = findInstance();
}

// Invalid usage
else {
	showUsage();
}

exit;


/// HELPER FUNCTIONS ///////////////////////////////////////////////////////////

function findInstance($instance = false, $silent = false) {
	global $AMI;
	
	if ($instance) {
		if (!$silent) echo "[".date("H:i:s")."] Check for running instance $instance ...";
	}
	else {
		if (!$silent) echo "[".date("H:i:s")."] Check for running instance of $AMI ...";
		$instance = "\S+";
	}

	// Already running?
	if (preg_match("/INSTANCE	($instance)	$AMI	(\S+)	\S+	running/s",`ec2-describe-instances`,$m)) {
		$instance = $m[1];
		$dns = $m[2];	
		if (!$silent) echo " $instance running at $dns\n";	
		
		return array(
			"instance" => $instance,
			"dns" => $dns
		);
	}
	
	if (!$silent) echo " Not running.\n";	
	return false;	
}

function showUsage() {
	die("Usage: {$_SERVER['PHP_SELF']} (start|stop|status)\n");
}


/// DEMO OUTPUT FOR PARSING ////////////////////////////////////////////////////
/*


$ ec2-run-instances $AMI -K keypair

RESERVATION	r-3a48a857	690724809999	default
INSTANCE	i-cf3f87a3	ami-2d4aa444			pending		0		m1.small	2011-01-28T00:40:38+0000	us-east-1b	aki-754aa41c			monitoring-disabled					instance-store		



$ ec2-describe-instances 

RESERVATION	r-907a9afd	690724809999	default
INSTANCE	i-7f4ff713	ami-2d4aa444			terminated	keypair	0		m1.small	2011-01-28T00:19:38+0000	us-east-1c	aki-754aa41c			monitoring-disabled					instance-store		
RESERVATION	r-3a48a857	690724809999	default
INSTANCE	i-cf3f87a3	ami-2d4aa444	ec2-50-16-143-122.compute-1.amazonaws.com	domU-12-31-39-03-44-65.compute-1.internal	running		0		m1.small	2011-01-28T00:40:38+0000	us-east-1b	aki-754aa41c			monitoring-disabled	50.16.143.122	10.249.71.147			instance-store		



$ ec2-terminate-instances i-fe8ce087
INSTANCE	i-fe8ce087	running	shutting-down



$ sudo apt-get install tinyproxy

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following NEW packages will be installed:
  tinyproxy
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 60.1 kB of archives.
After this operation, 200 kB of additional disk space will be used.
Get:1 http://us-east-1.ec2.archive.ubuntu.com/ubuntu/ precise/universe tinyproxy i386 1.8.3-1 [60.1 kB]
Fetched 60.1 kB in 0s (311 kB/s)
Selecting previously unselected package tinyproxy.
(Reading database ... 25420 files and directories currently installed.)
Unpacking tinyproxy (from .../tinyproxy_1.8.3-1_i386.deb) ...
Processing triggers for initramfs-tools ...
update-initramfs: Generating /boot/initrd.img-3.2.0-23-virtual
Processing triggers for man-db ...
Processing triggers for ureadahead ...
Setting up tinyproxy (1.8.3-1) ...
Starting tinyproxy: tinyproxy.



$ sudo apt-get install tinyproxy

Reading package lists... Done
Building dependency tree       
Reading state information... Done
tinyproxy is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.



$ http_proxy=http://localhost:8888 wget -O /dev/null http://www.google.com/ 2>&1

--2012-06-16 00:40:22--  http://www.google.com/
Resolving localhost (localhost)... 127.0.0.1
Connecting to localhost (localhost)|127.0.0.1|:8888... failed: Connection refused.


*/

?>