Ok, let me first start off by saying that I've only ever dealt with VPN access through windows by setting up a connection through the control panel. It's pretty simple since everything is pretty much a point-and-click setup.
I'm now working on a project where I need to access a computer cloud on a private network (there is no public IP directly to the cloud so it can only be accessed when I'm on the network). My project involves a website that needs to access that cloud "somehow". Because of my lack of experience/knowledge with VPN's through the command line and how to programmatically connect to a VPN, I've hit a mild obstacle that I'm hoping someone here can help me with.
What kind of server side scripting would I do to get a VPN connection up and running? The website is being hosted on a linux machine. Is their a "default" VPN utility under linux that I can call through PHP to establish a connection? If not, I would really appreciate any and all suggestions on how to circumvent this little problem of mine. FYI the VPN uses PPTP.
Looks like there is a little bit to getting it set up from a shell rather than the GUI, but here are some references that will hopefully help you out.
If you set up the connection and connect it, when your PHP script attempts to communicate with an IP address on the remote side of the connection, it will go through the PPTP connection. Having the connection always open is probably better than having to your PHP script connect every time it needs to do something.
http://ubuntuforums.org/showthread.php?t=1443735 - An easy PPTP client setup
http://pptpclient.sourceforge.net/ - Client you can install and configure
http://www.cyberciti.biz/tips/howto-configure-ubuntu-fedora-linux-pptp-client.html - Walk through of setting up PPTP using the linux PPTP network manager
Hopefully those will help you out a bit. The first one looks like it may be worth trying first.
Related
I'm doing a group project and we're creating an online game. We're about half way done and now it's time to implement a database to store our records/data and make the website go live on the internet.
I'm just confused on how PSQL works exactly. My understanding is that PSQL needs to be running on some server in order to access it. For previous assignments, I downloaded Postgres for my Mac and ran it on localhost. The PHP code was something along the lines of:
$dbconn = pg_connect("host=localhost port=5432 dbname=mydbname");
So, if we intend to use PSQL, where would the server be? Do one of us have to host the server? Can we use some sort of free online server? How do we connect to that server with PHP?
In summary, I have two main questions:
How do we make our code go live on the internet for free? (It's just a temporary website and will only be up for a few weeks at most)
How can we all access a shared PSQL database?
Sorry for the noob questions, I just got started with web development and am still learning.
So, if we intend to use PSQL, where would the server be? Do one of us have to host the server? Can we use some sort of free online server? How do we connect to that server with PHP?
PostGreSQL is going to have to run on some machine visible to anyone who needs to access it. If only your web server (i.e., the machine running PHP and your website) needs to talk to the PGSQL, then PGSQL can be installed on your web server. This is a very common configuration.
The server might also run on the LAN where your web server is running or it might be running on an entirely different network on a different continent. The most important thing is that any machine which must connect directly to the database can actually connect to it. If you're building a website, this means you have a web server. Your web server will need to connect to the PGSQL server. The second most important thing is that your web server and the PGSQL server should share a very fast connection for the sake of performance and efficiency.
It's probably most common for your web server to also host the database. On an ubuntu machine, installing a PostGreSQL server is as easy as running a few commands. A quick search yields many examples like this one.
How do we make our code go live on the internet for free? (It's just a temporary website and will only be up for a few weeks at most)
I don't know anyone who is in the habit of offering free web hosting or DBMS services. You could ask a friend. Or put an ad on craigslist or something. Or if you are tech-savvy (it doesn't sound like you are) then you could configure a high-end router at your home to use Dynamic DNS to point some domain at a machine running at your house.
How can we all access a shared PSQL database?
I have no experience with Heroku, but you might sniff around there. PostGreSQL's website also maintains a list of hosting companies. Amazon offers RDS instances running PGSQL. Digital Ocean has a variety of tutorials and how-tos on dealing with PostGres. You could probably fire up a 'droplet' server for super cheap and install it yourself without too much effort.
Amazon offer a free tier database solution for Postgres. Something like 300 hours (don't quote me on it) for a low level set up.
They have tutorials on doing this here:
https://aws.amazon.com/rds/?nc2=h_m1
Once set up you get the end point and your connection string becomes something like
db_connect ("host=[URLENDPOING] user=postgres dbname=postres")
I'm currently developing a PHP application that is going to use websockets for client-server communication. I've heard numerous times that PHP shouldn't be used for server applications because of the lack of threading mechanisms, its memory-management (cyclic references) or the unhandy socket library.
So far, everything is working quite well. I'm using phpws as the websocket library and the Doctrine DBAL to access different database systems; PHP is version 5.3.8 . The server should serve a maximum of 30 clients. Yet especially in the last days I've read several articles stating the ineffectiveness of PHP for long running applications.
Now I'm not aware whether I should continue using websockets with PHP or rebuild the entire serverside application. I've tried Python with Socket.IO, though I did not get the results I expected.
I guess I have the following options:
Keep everything as it is.
Make the application use Ajax in combination with Socket.IO - e.g. run a serverside script that invokes the client's ajax calls when data is submitted to the server.
The last point sounds quite interesting, though it would require some work .. Would it be a problem for servers to execute all the clients requests at one time?
What would you recommend? Is the problem with PHP's memory management (I'm using gc_collect each time a client sends data to the server) still valid? Are there other reasons beside the obvious reasons (no threading, ...) for not using PHP as a server?
You can try running your socket.io on a node server on another port on your server (that is if you are not using a hosting plan like goDaddy).
I am using it and the performances are really satisfying.
I have an apache server on the port 80 serving my php files, and my server-client communications are done using a Node.js server running socket.io on the port 8080 (dev) or 843 (prod).
Node.js is really light and has great performance, but you need to run it as a server. Nodejitsu.com is a hosting solution that has the websocket protocol available and is on beta, so it is still free for now. Just note that you need to listen on the port 80 with socket.io, this is a limitation from theyr network.
If you want your pages all to be accessed on the port 80 then you will need a reverse proxy like varnish .
I hope that helps! Have a nice day.
Are there other reasons beside the obvious reasons (no threading, ...)
for not using PHP as a server?
Yep, lots of socketfunctions are incompatible with each other and it's a hell to debug.
i tried something similar myself and quit frustrated sind every function i thought would make sense didnt do what i expected
I need to connect to a webservice which is behind of a VPN via PHP. My server is Debian Linux (Squeeze).
Is it possible to accomplish this via PHP on Linux?
Is it risky to do this if it is possible? (When VPN connection hangs etc., does the operating system or any other what-so-over handles the situation)
I have only one network card, therefore I really wonder whether it is possible to keep server online for normal users while "posting data over an accomplished VPN connection in the background".
Although my question seems to a conceptual question, any specific help is also welcome.
Server OS : Debian Linux Squeeze (x64)
Web Server : Apache HTTP
PHP Version: 5.3
Framework: Symfony 1.4
VPNs are at a network layer below PHP, PHP won't know or care that the connection is over a VPN or a normal connection. It's handled by the network stack.
If you use a permanent one (e.g. IPSEC) then PHP doesn't need to create the connection, it's just there to use when PHP connects to an IP address that is in the VPN. It is selected to use by the network layer when it does the routing, not by PHP. This is true even if you create the VPN on demand, as jderda suggested using exec() or similar. But a permanent connection is better (IPSEC).
So to answer your questions:
The question doesn't make sense, the only way PHP could do this is using PPTP or similar and exec() to bring the connection up, but better to use IPSEC
If the VPN connection hangs/dies PHP won't get a connection to the remote end and will timeout the connection.
Yes it is.
From PHP point of view, the VPN is just a plain network connection. It does not require additional handling.
If you want to dynamicaly estabilish a VPN connection, you'll probably need to use exec() and some commandline tool for estabilishing a connection. But as such connection doesn't interfere with normal network communication (as long as it's properly configured, with other subnet ip range), you should estabilish it once and keep it active for PHP and other apps to use.
I have a standard php app that uses SQL Server as the back-end database. There is a serious delay in response for each page I access. This is my development server, so its not an issue with the live setup, but it is really annoying for working on the system.
I have a 5 - 8 second delay on each page.
I am running SqlServer 2000 Developer Edition on a Virtual Machine (Virtual PC).
I have installed SqlServer on my development machine but get the same delay.
I have isolated the issue to the call to mssql_connect (calling mssql_pconnect has no effect)
It is a networking issue on how I have set up (or not set up, since I didn't really change default config) SQL server. It's not a strictly a programming issue but I thought I might get some valuable feedback here.
Can anyone tell me if there is a trick, specific set of protocols, registry setting, something that will kill this delay?
I was also experiencing a 5-10 second delay on every connect, using the official Microsoft SQL drivers for PHP (as suggested by #gaRex) - none of the answers posted here solved it for me.
As suggested by #ircmaxell, my problem was a DNS issue - and the solution was to edit the \windows\system32\drivers\etc\hosts file (your local local host file) and add the name of my own machine to it.
In the "system properties" dialog, find the "computer name" of your machine - then add a line like 127.0.0.1 my-computer to your local host file.
For me, the delay occurred once more, on the following attempt to load the page - after that, it was super fast, no delay at all.
Note that this problem may occur even on a physical machine, not only on a VM.
I came across network issues when running virtual pc, everything network related is slow, try adding this entry on your registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
Create new DWORD value named DisableTaskOffload and set its value to 1.
Restart the computer.
It worked for me, source.
Is it perhaps a DNS issue? I know that MySQL does a reverse DNS lookup on each login (not each connection). If you don't have a reverse dns record for your server (or your dns is slow) it can cause a major delay at login. There's an option in MySQL to disable that. I'm not sure about SQL Server, but I'd assume it may be doing something similar...
I remember the same problem, but forgot, how we have solve it.
To clarify please specify exact connect strings, your SQLserver versions and also try to start this old good utility c:\WINDOWS\system32\cliconfg.exe, which is also can bring some light.
Yes, I know, it's from 2k, but guys at m$ don't like to create client tools from scratch.
Also try to get "right" mssql client dlls for PHP.
What in the heck do you put as the host for Memcache::addServer($host, $port)?
I am hosting on mediatemple and this is really, really, really, really starting to get to me.
Do I have to set up a new memcahce server or what. I have no idea what to do and every tut just keeps saying "localhost". Well I don't want to run it on my localhost.... I guess I just don't understand what's going on.
Any help would be greatly appreciated.
"localhost" is whatever machine the code is running on. If the code is running on a server at MediaTemple, then "localhost" will be that server.
If they provide a memcache server, they should provide it's address somewhere in their knowledge base. Try "localhost" first, on the off chance that it's running on the same machine your site is hosted on.
UPDATE
Assuming you're running on their Grid service, try following these instructions:
http://kb.mediatemple.net/questions/854/Using+memcached+with+Django+or+Ruby+on+Rails+in+a+(gc)+GridContainer
Memcached is a service that provides access to a centralized RAM store which would enable caching for your application. Its default port is 11211. If your application requires it then it sounds like you will need access to one.
Most of the time though it's only used for caching and not having it means it will access your database for every request which can degrade your performance significantly depending on your scenario.