I am writing a Perl HTTP server using HTTP::Daemon. My Perl client is sending a HEAD request to the server to get the content length of the file which IO have to GET later.
My problem is that I am not able to generate a custom header and send it back to the client.
I can send back basic HTTP headers using $c->send_basic_header, but as soon as I try to send specific headers using $c->send_header( $field1, $value1, $field2, $value2, ... ) it does not work.
I am not able to understand what is the problem.
The headers which I am trying to send is
$c->send_header('Content-Type','image/jpeg','Cotent-Length','56360','Accept-Ranges','bytes')
I am new to Perl, so please help me understand how to do this.
You don't show your code, but do you realise that you need to send_basic_header as well as send_header?
Your code should look like this
$c->send_basic_header;
$c->send_header(
'Content-Type' => 'image/jpeg',
'Content-Length' => '56360',
'Accept-Ranges' => 'bytes',
);
$c->send_crlf;
Related
I'm trying to log in into a site which requires grcp content-type using requests. I alrady have a HTTP 2 client, but I don't know how body of my post request should look like.
When I'm trying to simply copy request as a curl from chrome network tab, request body looks like this:
%äEMAIL"PASSWORD(0
When I'm trying to request site with same body as I copied from chrome tab, I'mm getting response with this headers:
Grpc-Message: grpc: received message larger than max (218767392 vs. 4194304)
Grpc-Status: 8
I'm sure It's becouse wrong payload format
If anybody knows how can I pass data in request plase help.
If you're trying to send a one-off gRPC request, https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md would be helpful to know as to how to construct a message. Otherwise, using gRPC clients (https://github.com/grpc/grpc) would make more sense.
Нello, please take a look at this simple file server.js:
require('http').createServer((req, res) => {
res.end('hiii');
console.log('Response headers:', res.getHeaders());
}).listen(80);
Navigating to localhost:80 in my browser hits this endpoint. This causes the response of hiii to appear in the browser, and also the headers to be logged to stdout.
The strange thing is, the headers logged to stdout disagree with the headers the browser received.
Stdout shows me an object representing 0 headers:
Response headers: [Object: null prototype] {}
Developer tools show me that in fact, 3 response headers were received:
What accounts for this difference? I understand that the 3 headers shown in chrome are very fundamental to http. Is chrome receiving 0 headers, but filling them in by default? Is node's http library filling these headers in by default? If that's the case, why aren't they exposed via res.getHeaders()? Are these headers being calculated at some lower level, as in C libraries? If so is there any means of exposing these values?
I tried the following in case there is some kind of async delay where the headers are calculated:
require('http').createServer((req, res) => {
res.end('hiii');
setTimeout(() => console.log('Response headers:', res.getHeaders()), 3000);
}).listen(80);
But nonetheless, 0 headers are sent to stdout.
Somewhere, these 3 headers are being calculated! How can I access these calculated header values??
I found them under res.socket._httpMessage._header
require('http').createServer((req, res) => {
res.setHeader('HELLO', 'WORLD')
res.end('hiii');
console.log(res.getHeaders())
console.log(res.socket._httpMessage._header)
}).listen(8000);
You can't get them using getHeaders because they are not set using the regular API but they are sent by nodejs internaly.
If you define a header yourself using setHeader then you'll be able to retrieve it using getHeaders
Response headers are not generated by the client since it needs them to be able to process the response. How can the client read the request if it doesn't know the size of the body (Content-Length).
These communication rules are defined in the HTTP RFC and the server must implement them so the client can understand the message it receives.
NodeJS calculates these information internaly (source code exampe here) and probably sends them somehow in the socket without storing them in the high level API that you are using. (another source code example)
i' m a bit new to Node, so question may be stupid...
I am sending a POST request to a website (through http.request) and I want to be able to use the invisible POST data I get along the response.
I hope this is achievable, and I think so since I am able to preview those data in Chrome debugger.
PS : I understand that we can use BodyParser to parse and get those while listening for a POST call server side, but I have found no example of how to use it coupled with an http.request.
Thanks !
If the body of the HTTP response contains JSON, then you need to parse it first in order to turn it from a string into a JavaScript object, like this:
var obj = JSON.parse(body);
console.log(obj.response.auth_token);
More info on various ways of sending a POST request to a server can be found here: How to make an HTTP POST request in node.js?
Edit : So we figured it out in the comments. The value I needed was in the form to begin with, as a hidden field. My error was to think it was generated afterward. So I'll just grab it first then login, so I can use it again for future POST requests on the website.
There's a large binary file at somwhere.com/noo.bin
I want to send this to the user on my web app.
I don't want to save this file on my server and then serve it, wondering if there's a way to stream the file in which my web app acts as the proxy (the file will look like mysite.com/noo.bin)
Install request, then:
var http = require('http'),
request = require('request'),
remote = 'http://somewhere.com';
http.createServer(function (req, res) {
// http://somewhere.com/noo.bin
var remoteUrl = remote + req.url;
request(remoteUrl).pipe(res);
}).listen(8080);
Though I would have written exactly #LaurentPerrin's answer myself, for completeness sake I should say this:
The drawback in that method is that the request headers you are sending to somewhere.com are unrelated to the request headers your server got. For example: if the request sent to you has a specific value for Accept-Language, it is likely that (as the code stands) you are not going to specify the same value for Accept-Value when proxying from somewhere.com. Thus the resource might be returned to you (and then from you to the original requester) in the wrong language.
Or if the request to you comes in with Accept-Encoding: gzip, the current code will get the large file uncompressed, and will stream it back uncompressed, when you could have saved bandwidth and time by accepting and streaming back a compressed file.
This may or may not be of relevance to you.
If there are important headers you feel you need to pass, you could either add some code to explicitly copy them from your request to the request you are sending somewhere.com, and then copy relevant response headers back, or use node-http-proxy at https://github.com/nodejitsu/node-http-proxy.
An example for a forward proxy using node-http proxy is https://github.com/nodejitsu/node-http-proxy/blob/master/examples/http/forward-proxy.js
I've written an express web app route that is essentially a proxy - it pipes the contents of an input stream (a zip file) into the server response's output stream.
I'd like the browser to prompt the user for download or whatever is most appropriate for a zip file. However, when I load this route in a browser, the contents of the input stream (the zip file's contents) show up in the browser window as text, rather than prompting a download. l
This is the code sending the response:
res.statusCode = 200;
res.setHeader ('Content-Length', size);
res.setHeader ('Content-Type', 'application/zip');
console.log ("content-type is " + res.header('Content-Type'));
inputStream.pipe (res);
The console.log statement above outputs "content-type is application/zip".
However, when I examine the request in Chrome's network tab, I see that the response's content-type is "application/json". This implies that express, or something else, is overriding my content-type header, or perhaps has already sent it.
Does anyone know what is changing the content-type on me, and how I could make sure the content-type is the one I set?
Thanks for any help.
You should check the order of the middleware, it's really tricky and can mess things up if they are in the correct order.
You can check the correct order here in the Connect webpage