I am very confused with proxy server, and proxy and this word proxy. I saw everywhere people are using proxy program, proxy server. Some of them using the proxy websites to unblock the websites. There are lot of things like reverse-proxy like that..
When I read one article about nginx I ran into one pic it says proxy cache. So what's proxy cache?
And how can I write a proxy program? What does that mean ? Why we need to use a proxy program?
Anybody can answer my question as simple as possible, I am not much in to this area.
A proxy server is used to facilitate security, administrative control or caching service, among other possibilities. In a personal computing context, proxy servers are used to enable user privacy and anonymous surfing. Proxy servers are used for both legal and illegal purposes.
On corporate networks, a proxy server is associated with -- or is part of -- a gateway server that separates the network from external networks (typically the Internet) and a firewall that protects the network from outside intrusion. A proxy server may exist in the same machine with a firewall server or it may be on a separate server and forward requests through the firewall. Proxy servers are used for both legal and illegal purposes.
When a proxy server receives a request for an Internet service (such as a Web page request), it looks in its local cache of previously downloaded Web pages. If it finds the page, it returns it to the user without needing to forward the request to the Internet. If the page is not in the cache, the proxy server, acting as a client on behalf of the user, uses one of its own IP addresses to request the page from the server out on the Internet. When the page is returned, the proxy server relates it to the original request and forwards it on to the user.
To the user, the proxy server is invisible; all Internet requests and returned responses appear to be directly with the addressed Internet server. (The proxy is not quite invisible; its IP address has to be specified as a configuration option to the browser or other protocol program.)
An advantage of a proxy server is that its cache can serve all users. If one or more Internet sites are frequently requested, these are likely to be in the proxy's cache, which will improve user response time. A proxy can also log its interactions, which can be helpful for troubleshooting.
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Suppose we have two servers serving requests through a load balancer. Is it necessary to have web server in both of our servers to process the requests. Can load balancer itself act as a web server. Suppose we are using apache web server and HAProxy. So does that mean that web server(Apache) should be installed in both the server and load balancer in any one of the server. Why can't we have load balancer in both of our server machine that will be receiving the request and talking to each other to process the requests.
At the very basic, you want to have Webservers fulfill requests for static contents, while Application servers handle business logics, i.e. handle requests for dynamic contents.
But Web servers can do many other things as well such as authenticate and validate requests, logging metrics. Also, the important part of Webserver is putting the Content it gets from Application servers with a View for client to represent.
You want to have LB sitting in front of both Web and App servers if you have more than one server. Also, there's nothing preventing you from putting both Web and App server in one.
The load balancer is in front of your webserver(s) to redirect requests according to number of sessions, a hash of source IP and destination IP, requested URL or other criteria. Additionally, it will check availability of the backend servers to ensure requests get answered even if one server fails.
It's not installed on every webserver - you only need one instance. It could be a hardware appliance, or a software (like HAproxy) which may or may not be installed on one of the webservers. Although this would not be prudent, as this webserver could fail and then the proxy would not be able to redirect traffic to the remaining server.
There are several different scenarios for this. One is load balancing requests to 2 webservers which serve the same HTML content, to provide redundancy.
Another would be to provide multiple websites using just one public address, i.e. applying destination NAT according to the requested URL. For this, the software has to determine the URL in the HTML request and redirect traffic to the backend webserver servicing this site. This sometimes is called 'reverse proxy' as it hides the internal server addresses from the outside.
I'm trying to upgrade a websocket connection ws:// to wss:// using a nginx reverse proxy https://github.com/nicokaiser/nginx-websocket-proxy/blob/master/simple-wss.conf
but I seem to be having trouble with the certificate part. My server is located on the same network as the client. So Ideally I would want my users to log in to "https://example.com" and then the client makes a connection to "wss://192.168.1.xxx:xxxx".
As of now the browsers are blocking it because of NET::ERR_CERT_COMMON_NAME_INVALID. I don't really know to produce a self signed certificate that the browsers will trust on the local network. Googling only gives me answers on how to do it if my server would be accessed using a domain name but I will always connect to a local network IP. Help is appreciated!
To anyone coming across this I managed to solve it using this post outlining the architecture https://support.plex.tv/articles/206225077-how-to-use-secure-server-connections/
What ended up happening was that we set up a url pointing to a server running nginx which parsed the subdomain and redirected the connection to that url. For example: wss://192-168-1-142.mydomain.com redirects to ws://192.168.1.142 which makes the browser trust the connection
Does this work?
Your post is a year old now and browsers have become stricter since then. Usually, a browser will produce 'mixed content' errors if you access HTTP content from a HTTPS page, and the only way to get round this is to change the site settings to allow insecure content, which is scary for users in the face of a big warning message.
If accessing an HTTPS web address redirects to an HTTP local IP address, won't the browser still complain about mixed content?
I have a similar situation to you. I am writing a Progressive Web Application (PWA) to control network music players on a home network. The players only support HTTP but a PWA requires HTTPS for services workers to work and to allow the app to be 'installed'.
My solution is to run a local server on the home network which can talk to the players over HTTP. Then I can access this server over HTTPS from my browser so that the browser itself is not making any HTTP calls.
This works fine if the server is on localhost because localhost is a special case where security rules are relaxed. But if the server is on another machine, how can I create an SSL certificate since (1) it seems that local IP addresses are not allowed in the Subject Alternative Name (SAN) section of the certificate, and (2) I won't know in advance what the IP address of the server will be.
If your workaround works, then the local server can use HTTP instead so I won't need a certificate. The local server can register itself with a web server, and then the browser can connect over HTTPS to the web server, which would redirect to the IP address of the local server over HTTP.
But does this trick work?
I recently signed up for CloudFlare to take advantage of the security feautres the service provides. Specifically, I'm interested in its use against DDOS attacks (which are a problem I'm facing).
My web application employs nginx as a reverse proxy (with gunicorn as the application server). The Ubuntu-based virtual machine - procured via Azure - has a static/reserved IP (used as a VIP). I've read that after connecting to CloudFlare, it's best practice to change server IP so that malicious actors can't directly DDOS the said server.
Being a newbie, I'm unsure whether this guideline was applicable to the public VIP (virtual IP) or to the internal IP (which is entirely different). Can someone please conceptually and functionally clarify this for me? Can really use some help in setting this up!
What services like CloudFlare do is acting like a CDN for your website. They become front-end of your content delivery to clients while they have vast network for doing so (resources i.e. bandwidth which are consumed by DDoS). Then your IP is just known by the anti-DDoS service provider to fetch the content and deliver on your behalf.
You see if the IP is leaked by any mean the whole defense mechanism become useless since attackers can directly point to your machine while dynamic DNS of CloudFlare would distribute requests to its network and serve clients via them.
Since your website was up for a while before you migrate to CloudFlare your current public IP is known to attackers and hiding behind CloudFlare is useless since they don't ask CloudFlare DNS service and directly attack your server. This is the reason you need a new IP and the new one should not be revealed by any mean. Just set it in your CloudFlare panel and don't use it for other purposes.
I faced attacks too and used CloudFlare to prevent them, however, I have learned how to perform those attacks by myself and also how to bypass CloudFlare and take down the protected website. The best practice is to secure your server by yourself. Using nginx as a reverse proxy is a good option.
I'm trying to set up a reverse proxy on Apache 2.2 (Windows). I am able to do it on a non-corporate network without any problems. I am attempting to reverse proxy content from a vendor domain, but keep it under my own domain for SEO reasons.
dev.example.com/stuff ===> devstuff.vendor.com
However, when I try to incorporate this on my internal network, the Internet Gateway proxy is blocking the request, presumably as I'm not properly authenticating the call to the external domain.
dev.example.com ===> Internet Proxy =X=> devstuff.vendor.com
I've been googling every term I can think of and reading the Apache docs and can't find anything which seems to work. I have tried running Apache as a service with a network account which would have access, but naturally, it's probably not trying to use the proxy at all.
Is there any way to tell Apache to send external ProxyPass requests to use a specific proxy server, and perhaps a specific username/password as well? I'd love to avoid modifying the proxy or firewall too heavily to accomplish this.
Thanks!
Never quite did figure out the "with passing credentials" part, but using the ProxyRemote directive, we could pass everything for our devstuff.vendor.com domain through our network proxy. From there, we had a proxy exception put in to allow from our web server IPs without authentication, since this was an approved arrangement anyhow.
Though, in hindsight, even after solving this, we ended up backing up one step further and just going straight out the firewall for performance reasons (both for the end user with too many hops) as well as negative impacts to our proxy server.
I have an HTTP server which is in our internal network and accessible only from inside it. I would like to put another server that would listen to an HTTPS port accessible from outside, and forward the requests to that HTTP server (and send back the responses via HTTPS). I know that there are several ways to do this with some programming involved (and I myself made a temporary solution with Tomcat and a very simple servlet I wrote), but is there a way to do the same just plugging parts already made (like Apache + modules)?
This is the sort of use-case that stunnel is designed for. There is a specific example of using stunnel to wrap an HTTP server.
You should consider whether this is really a good idea, though. Web applications designed for use inside a corporate firewall are often fairly lax about security. Merely encrypting the connections prevents casual eavesdropping, but does not secure the site. If an attacker finds your outward facing server and starts connecting to it, they can still try to find exploitable flaws in the web service (SQL injection, cross-site scripting, etc).
With Apache look into mod_proxy.
Apache 2.2 mod_proxy docs
Apache 2.0 mod_proxy docs