Sending http request behind nginx - nginx

I am not sure how to formulate my question but here we go:
I have 2 servers, one is the nginx reverse proxy and one is the app server.
In my app server, I am developing a simple http client using jerseyclient that will send a request to another server. I can do this now but the traffic goes from the app server and directly to the destination. Is it possible to it from the app server, passes through the reverse proxy server and goes to the destination?
And, is this design ok or is it an abomination?

nginx reverse proxy works only for requests outside your network.
To configure your system works as you described you have to configure firewall NAT or caching HTTP proxy like squid etc.
If you have no reasons why your servers should look as single computer - your configuration is OK.

Related

Reverse proxy with http inbound, https outbound, and parent proxy

I have an application that needs to use a proxy (call it proxy1) to access some https endpoints outside of its network. The application doesn't support proxy settings, so I'd like to provide it a reverse proxy url, and I would prefer not to provide tls certs for proxy1, so I would use http for application -> proxy1.
I don't have access to the application host or forward proxy mentioned below, so I cannot configure networking there.
The endpoints the application needs are https, so proxy1 must make its outbound connections via https.
Finally, this whole setup is within a corporate network that requires a forward proxy (call it proxy2) for outbound internet, so my proxy1 needs to chain to proxy2 / use it as a parent.
I tried squid and it worked well for http only, but I couldn't get it to accept http inbound while using https outbound. Squid easily supported the parent proxy2.
I tried haproxy, but had the same result as with squid.
I tried nginx and it did what I wanted with http -> proxy -> https, but doesn't support a parent proxy. I considered setting up socat as in this answer, or using proxy_pass and proxy_set_header as in this answer, but I can't shake the feeling there's a cleaner way to achieve the requirements.
This doesn't seem like an outlandish setup, is it? Or is there a preferred approach for it? Ideally one using squid or nginx.
You can achive this without the complexity by using a port forwarder like socat. Just install it on a host to do the forwarding (or locally on the app server if you wish to) and create a listener that forwards connections through the proxy server. Then on your application host use a local name resolution overide to map the FQDN to the forwarder.
So, the final config should be the app server using a URI that points to the forwarding server (using its address if no name resolution excists), which has a socat listener that points to the the corporate proxy. No reverse proxy required.
socat TCP4-LISTEN:443,reuseaddr,fork \
PROXY:{proxy_address}:{endpoint_fqdn}:443,proxyport={proxy_port}
Just update with your parameters.

How to handle POST/GET with an https URL in proxy?

I wrote a proxy server which works well. But when looking at the log, there are some weird requests like:
POST https://vortex.data.microsoft.com/collect/v1 HTTP/1.1
Also some GET over https. I think only CONNECT is allowed over https, am I wrong? If I am wrong, how to deal with these request? (I just dropped these requests in my app.)
Another thing maybe unrelated is all these requests are related to microsoft from the log.
There isn't any problem handling any HTTP Method with HTTPS within a proxy.
All the requests with https://-protocol will be automatically received and sent to port 443 if not indicated otherwise.
Independently if you have a server where you deployed a HAProxy, NGINX, Apache Web Server or that you literally wrote a proxy like this one in JavaScript, only thing you have to do is to literally proxy the requests to the destination server address.
Regarding the encryption, precisely HTTPS ensures that there are no eavesdroppers between the client and the actual target, so the Proxy would act as initial target and then this would transparently intercept the connection.
Client starts HTTPS session to Proxy
Proxy intercepts and returns its certificate, signed by a CA trusted by the client.
Proxy starts HTTPS session to Target
Target returns its certificate, signed by a CA trusted by the Proxy.
Proxy streams content, decrypt and re-encrypt with its certificate.
Basically it's a concatenation of two HTTPS sessions, one between the client and the proxy and other between the proxy and the final destination.

How to forward requests from internet to k8s services

I tried to search, but I can't find nothing.
What I have:
single node k8s cluster
two game servers(project zomboid and valheim)
some web app listening http requests
My problem is
I can't access my services. I don't know what to do to forward requests from internet directly to my services.
I tried to make nginx server on host machine and forward using reverse proxy. It is working good for http requests. I can forward each subdomain.domain.com to each of my services.
My Questions
What about tcp/udp requests?
How I can forward them?
Is it a good way having nginx on host machine?
Is it possible to route tcp/udp requests by domain name(e.g. mygameserver:700 redirects to gameserver1 ip and myanothergameserver:700 redirects to anothergameserver ip?
kubectl get all

Is it possible to have client certificates with HTTP (not HTTPS)?

I have an application set up like this:
There is a server, with a reverseproxy/load balancer that acts as the HTTPS termination (this is the one that has a server certificate), and several applications behind it(*)
However, some applications require authentication of the client with a certificate. Authentication cannot happen in the reverse proxy. Will the application be able to see the user certificate, or will it be jettisoned by the HTTPS->HTTP transfer?
(*) OK, so this is a Kubernetes ingress, and containers/pods.
It will be lost. I think you need to extract it in the reverse proxy (i.e. Nginx) and pass it in as a HTTP header if you really must. See for example https://serverfault.com/questions/788895/nginx-reverse-proxy-pass-through-client-certificate. Not very secure as the cert is passed in the clear!
I don't know if we have that level of control over the ingress, personally I'm using a normal Nginx server for incoming traffic instead.

Intercepting application HTTP/HTTPS traffic with a proxy

As part of my job,
I need to intercept the communication between a native windows application to a web server.
My connection to the environment is through an SSL-VPN.
The application (.exe) is installed on my PC and is communicating in HTTPS with the web server over port 1912.
Usually I use Burp proxy in order to intercept the communication between a browser and a server (configuring the proxy through the browser config). Yet,
In this implementation (native windows application) I cannot figure out how to route the traffic to a proxy.
Is there any specific proxy or configuration which I can use in order to that and use Burp (because it is a web proxy.. I need to mess with HTTP requests)?
First thing you have to understand is whether this native application is programmed to use proxy. If it can use proxy, it could obtain proxy information from the Windows system or you might need to configure just for the application inside the application.
Other possibility it to use the default gateway, and redirect requests with HTTP response 3XX to your proxy. It might work depending on your native application. The default gateway might just act as a proxy.
I suppose here you are not talking about reverse proxy and forward proxy caching (https://docs.trafficserver.apache.org/en/4.2.x/admin/reverse-proxy-http-redirects.en.html)

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