I am using nginx in front of apache servers as a load balancer and to log access logs. To log some variables from web services to the nginx log, the services are writing to Http header which gets extracted by nginx. The problem is that these variables are rather internal info which I want to remove before passing back to the client. Is there an easy of removing specific http header line(s) in nginx?
Which headers are passed from a proxied server to the client that made the request can be controlled with the config entries for proxy_hide_header and proxy_pass_header.
The 'pass' one forces headers that are normally removed to be shown to the client, and the hide one forces headers that are normally shown to be removed.
This allows you to remove or hide headers that you don't want to be shown to the end user.
Related
I need to add some custom headers into a request that gets sent through an NGINX to a reverse proxy. Unfortunately, the "outer" nginx, sitting on the EC2 instance where the docker network of the application is sat, appears to be not passing the extra headers we've added.
So two questions:
Practically how do I log this -- check the docs and can't see how to log all headers for an incoming request as it seems to be doing known headers only.
How do I pass through the "new" or "unknown" headers?
I have a server which acts as a middle man between an HTTP client that I don't control and a remote file hosting server I don't control. I want to expose a URL through which the client can download a chunk (specified by HTTP range headers my server provides) of a file on the remote server.
There are two important constraints here: I'd like to facilitate this partial download without having the response flow back through my server (response goes straight to client) and without writing a custom client. How can I accomplish this?
One option I tried was having my endpoint send a redirect response with the range headers set on the response, but unfortunately those do not get forwarded onto the subsequent request from the client and as a result the entire file is downloaded. Are there any other hacky tricks / network wizardry I can employ to achieve this end given the constraints?
i am also thinking about this since 5 days it's like the server give you file only when you give required header from your side and without header it will deny your request and middleman if it does get request with required header then file will be accessable through your middleman to client and you are trying to client get file from server not from your custom server which is trying to pass headers to server for your client
I have a web application running on a server (let's say on localhost:8000) behind a reverse proxy on that same server (on myserver.example:80). Because of the way the reverse proxy works, the application sees an incoming request targeted at localhost:8000 and the framework I'm using therefore tries to generate absolute URLs that look like localhost:8000/some/ressource instead of myserver.example/some/ressource.
What would be "the correct way" of generating an absolute URL (namely, determining what hostname to use) from behind a proxy server like that? The specific proxy server, framework and language don't matter, I mean this more in an HTTP sense.
From my initial research:
RFC7230 explicitly says that proxies MUST change the Host header when passing the request along to make it look like the request came from them, so it would look like using Host to determine what hostname to use for the URL, yet in most places where I have looked, the general advice seems to be to configure your reverse proxy to not change the Host header (counter to the spec) when passing the request along.
RFC7230 also says that "request URI reconstruction" should use the following fields in order to find what "authority component" to use, though that seems to also only apply from the point-of-view of the agent that emitted that request, such as the proxy:
Fixed URI authority component from the server or outbound gateway config
The authority component from the request's firsr line if it's a complete URI instead of a path
The Host header if it's present and not empty
The listening address or hostname, alongside with the incoming port number if it's not the default one for the protocol
HTTP 1.0 didn't have a Host header at all, and that header was added for routing purposes, not for URL authority resolution.
There are headers that are made specifically to let proxies to send the old value of Host after routing, such as Via, Forwarded and the unofficial X-Forwarded-Host, which some servers and frameworks will check, but not all, and it's unclear which one should even take priority given how there's 3 of them.
EDIT: I also don't know whether HTTPS would work differently in that regard, given that the headers are part of the encrypted payload and routing has to be performed another way because of this.
In general I find it’s best to set the real host and port explicitly in the application rather than try to guess these from the incoming request.
So for example Jira allows you to set the Base URL through which Jira will be accessed (which may be different to the one that it is actually run as). This means you can have Jira running on port 8080 and have Apache or Nginx in front of it (on the same or even a different server) on port 80 and 443.
I have a simple requirement. I have a nginx web server and a netscaler proxy. From netscaler, the option Client_IP header is checked, and name of header is HTTP_CLIENT_IP.
I want to access this ip in nginx log. I have specified a custom log format, so i can access this value:
I have tried the following variables in the log format, and they just return in '-'.
$http_client_ip
$http_request_body
Basically, i want to read the entire request header / body that nginx receives from netscaler.
Any help would be appreciated !
Netscaler inserts a http header with the client ip, if enabled. However You have to configure the http header name on the netscaler.
I am trying to write (and understand) a transparent proxy.
My setup would look like this
Client Browser ---> TProxy ----> Upstream Proxy ------> cloud
When the client browser makes a GET request, the idea is TProxy would then CONNECT to the Upstream proxy. The upstream proxy requires digest authentication. So, essentially the flow would look like
Client Browser ---> TProxy --------> Upstream Proxy ---------------> cloud
GET BBC.co.uk
CONNECT
407 PROXY AUTH REQUIRED
CONNECT
(with proxy-authorization)
200 OK
GET BBC.co.uk
I am confused what happens once CONNECT with authorization succeeds.
Am I suppose to modify the original GET request now to include a
Proxy-Authorization header?
or would the original GET request be then tunnelled in another http header something like
HTTP Header
Proxy Authorization
HTTP Header (GET BBC.CO.UK)
Data
or I can just pass the original GET request as is?
I am just starting with http and would appreciate any help.
Thanks
When you authenticate upstream from your transparent proxy, the Proxy-Authorization header applies only to the CONNECT.
The GET requests happen within the tunnel, so the upstream explicit proxy is not supposed to see them, and for sure does not expect any proxy authentication headers on them.
In short, you do not need to worry about the GET, but not because of the answer given above, but because there is a tunnel between the transparent proxy and the site, and the explicit proxy only sees and authenticates the CONNECT.
There is no such thing as nested headers in HTTP.
A proxy - whether transparent or not - always terminates the HTTP connection from the client, and initiates a new one to the server.
That means that the HTTP GET from the client goes to your TProxy. TProxy creates a new GET request to Upstream Proxy. Ideally, TProxy will simply pass on all the headers. That would make it (nearly) undetectable.
The same goes in reverse for the response headers.
In reality, proxy servers will, and in many cases have to, manipulate some headers. They will often add their own header (for instance, to alert the communication partners to the presence of a proxy), and they can also manipulate existing headers.
So, the short answer to your question: whatever header field your TProxy receives, pass it on unchanged unless you fully understand the implications.