HTTP

  1. Stability: 3 - Stable

To use the HTTP server and client one must require('http').

The HTTP interfaces in Node are designed to support many features
of the protocol which have been traditionally difficult to use.
In particular, large, possibly chunk-encoded, messages. The interface is
careful to never buffer entire requests or responses—the
user is able to stream data.

HTTP message headers are represented by an object like this:

  1. { 'content-length': '123',
  2.   'content-type': 'text/plain',
  3.   'connection': 'keep-alive',
  4.   'host': 'mysite.com',
  5.   'accept': '*/*' }

Keys are lowercased. Values are not modified.

In order to support the full spectrum of possible HTTP applications, Node’s
HTTP API is very low-level. It deals with stream handling and message
parsing only. It parses a message into headers and body but it does not
parse the actual headers or the body.

Defined headers that allow multiple values are concatenated with a ,
character, except for the set-cookie and cookie headers which are
represented as an array of values. Headers such as content-length
which can only have a single value are parsed accordingly, and only a
single value is represented on the parsed object.

The raw headers as they were received are retained in the rawHeaders
property, which is an array of [key, value, key2, value2, ...]. For
example, the previous message header object might have a rawHeaders
list like the following:

  1. [ 'ConTent-Length', '123456',
  2.   'content-LENGTH', '123',
  3.   'content-type', 'text/plain',
  4.   'CONNECTION', 'keep-alive',
  5.   'Host', 'mysite.com',
  6.   'accepT', '*/*' ]

http.METHODS

  • {Array}

A list of the HTTP methods that are supported by the parser.

http.STATUS_CODES

  • {Object}

A collection of all the standard HTTP response status codes, and the
short description of each. For example, http.STATUS_CODES[404] === 'Not Found'.

http.createServer([requestListener])

Returns a new instance of http.Server.

The requestListener is a function which is automatically
added to the 'request' event.

http.createClient([port][, host])

This function is deprecated; please use http.request() instead.
Constructs a new HTTP client. port and host refer to the server to be
connected to.

Class: http.Server

This is an EventEmitter with the following events:

Event: ‘request’

function (request, response) { }

Emitted each time there is a request. Note that there may be multiple requests
per connection (in the case of keep-alive connections).
request is an instance of http.IncomingMessage and response is
an instance of http.ServerResponse.

Event: ‘connection’

function (socket) { }

When a new TCP stream is established. socket is an object of type
net.Socket. Usually users will not want to access this event. In
particular, the socket will not emit readable events because of how
the protocol parser attaches to the socket. The socket can also be
accessed at request.connection.

Event: ‘close’

function () { }

Emitted when the server closes.

Event: ‘checkContinue’

function (request, response) { }

Emitted each time a request with an http Expect: 100-continue is received.
If this event isn’t listened for, the server will automatically respond
with a 100 Continue as appropriate.

Handling this event involves calling response.writeContinue() if the client
should continue to send the request body, or generating an appropriate HTTP
response (e.g., 400 Bad Request) if the client should not continue to send the
request body.

Note that when this event is emitted and handled, the request event will
not be emitted.

Event: ‘connect’

function (request, socket, head) { }

Emitted each time a client requests a http CONNECT method. If this event isn’t
listened for, then clients requesting a CONNECT method will have their
connections closed.

  • request is the arguments for the http request, as it is in the request
    event.
  • socket is the network socket between the server and client.
  • head is an instance of Buffer, the first packet of the tunneling stream,
    this may be empty.

After this event is emitted, the request’s socket will not have a data
event listener, meaning you will need to bind to it in order to handle data
sent to the server on that socket.

Event: ‘upgrade’

function (request, socket, head) { }

Emitted each time a client requests a http upgrade. If this event isn’t
listened for, then clients requesting an upgrade will have their connections
closed.

  • request is the arguments for the http request, as it is in the request
    event.
  • socket is the network socket between the server and client.
  • head is an instance of Buffer, the first packet of the upgraded stream,
    this may be empty.

After this event is emitted, the request’s socket will not have a data
event listener, meaning you will need to bind to it in order to handle data
sent to the server on that socket.

Event: ‘clientError’

function (exception, socket) { }

If a client connection emits an ‘error’ event, it will be forwarded here.

socket is the net.Socket object that the error originated from.

server.listen(port[, hostname][, backlog][, callback])

Begin accepting connections on the specified port and hostname. If the
hostname is omitted, the server will accept connections directed to any
IPv4 address (INADDR_ANY).

To listen to a unix socket, supply a filename instead of port and hostname.

Backlog is the maximum length of the queue of pending connections.
The actual length will be determined by your OS through sysctl settings such as
tcp_max_syn_backlog and somaxconn on linux. The default value of this
parameter is 511 (not 512).

This function is asynchronous. The last parameter callback will be added as
a listener for the ‘listening’ event. See also net.Server.listen(port).

server.listen(path[, callback])

Start a UNIX socket server listening for connections on the given path.

This function is asynchronous. The last parameter callback will be added as
a listener for the ‘listening’ event. See also net.Server.listen(path).

server.listen(handle[, callback])

  • handle {Object}
  • callback {Function}

The handle object can be set to either a server or socket (anything
with an underlying _handle member), or a {fd: <n>} object.

This will cause the server to accept connections on the specified
handle, but it is presumed that the file descriptor or handle has
already been bound to a port or domain socket.

Listening on a file descriptor is not supported on Windows.

This function is asynchronous. The last parameter callback will be added as
a listener for the ‘listening’ event.
See also net.Server.listen().

server.close([callback])

Stops the server from accepting new connections. See net.Server.close().

server.maxHeadersCount

Limits maximum incoming headers count, equal to 1000 by default. If set to 0 -
no limit will be applied.

server.setTimeout(msecs, callback)

  • msecs {Number}
  • callback {Function}

Sets the timeout value for sockets, and emits a 'timeout' event on
the Server object, passing the socket as an argument, if a timeout
occurs.

If there is a 'timeout' event listener on the Server object, then it
will be called with the timed-out socket as an argument.

By default, the Server’s timeout value is 2 minutes, and sockets are
destroyed automatically if they time out. However, if you assign a
callback to the Server’s 'timeout' event, then you are responsible
for handling socket timeouts.

server.timeout

  • {Number} Default = 120000 (2 minutes)

The number of milliseconds of inactivity before a socket is presumed
to have timed out.

Note that the socket timeout logic is set up on connection, so
changing this value only affects new connections to the server, not
any existing connections.

Set to 0 to disable any kind of automatic timeout behavior on incoming
connections.

Class: http.ServerResponse

This object is created internally by a HTTP server—not by the user. It is
passed as the second parameter to the 'request' event.

The response implements the Writable Stream interface. This is an
EventEmitter with the following events:

Event: ‘close’

function () { }

Indicates that the underlying connection was terminated before
response.end() was called or able to flush.

Event: ‘finish’

function () { }

Emitted when the response has been sent. More specifically, this event is
emitted when the last segment of the response headers and body have been
handed off to the operating system for transmission over the network. It
does not imply that the client has received anything yet.

After this event, no more events will be emitted on the response object.

response.writeContinue()

Sends a HTTP/1.1 100 Continue message to the client, indicating that
the request body should be sent. See the ‘checkContinue’ event on Server.

response.writeHead(statusCode[, statusMessage][, headers])

Sends a response header to the request. The status code is a 3-digit HTTP
status code, like 404. The last argument, headers, are the response headers.
Optionally one can give a human-readable statusMessage as the second
argument.

Example:

  1. var body = 'hello world';
  2. response.writeHead(200, {
  3.   'Content-Length': body.length,
  4.   'Content-Type': 'text/plain' });

This method must only be called once on a message and it must
be called before response.end() is called.

If you call response.write() or response.end() before calling this, the
implicit/mutable headers will be calculated and call this function for you.

Note that Content-Length is given in bytes not characters. The above example
works because the string 'hello world' contains only single byte characters.
If the body contains higher coded characters then Buffer.byteLength()
should be used to determine the number of bytes in a given encoding.
And Node does not check whether Content-Length and the length of the body
which has been transmitted are equal or not.

response.setTimeout(msecs, callback)

  • msecs {Number}
  • callback {Function}

Sets the Socket’s timeout value to msecs. If a callback is
provided, then it is added as a listener on the 'timeout' event on
the response object.

If no 'timeout' listener is added to the request, the response, or
the server, then sockets are destroyed when they time out. If you
assign a handler on the request, the response, or the server’s
'timeout' events, then it is your responsibility to handle timed out
sockets.

response.statusCode

When using implicit headers (not calling response.writeHead() explicitly),
this property controls the status code that will be sent to the client when
the headers get flushed.

Example:

  1. response.statusCode = 404;

After response header was sent to the client, this property indicates the
status code which was sent out.

response.statusMessage

When using implicit headers (not calling response.writeHead() explicitly), this property
controls the status message that will be sent to the client when the headers get
flushed. If this is left as undefined then the standard message for the status
code will be used.

Example:

  1. response.statusMessage = 'Not found';

After response header was sent to the client, this property indicates the
status message which was sent out.

response.setHeader(name, value)

Sets a single header value for implicit headers. If this header already exists
in the to-be-sent headers, its value will be replaced. Use an array of strings
here if you need to send multiple headers with the same name.

Example:

  1. response.setHeader("Content-Type", "text/html");

or

  1. response.setHeader("Set-Cookie", ["type=ninja", "language=javascript"]);

response.headersSent

Boolean (read-only). True if headers were sent, false otherwise.

response.sendDate

When true, the Date header will be automatically generated and sent in
the response if it is not already present in the headers. Defaults to true.

This should only be disabled for testing; HTTP requires the Date header
in responses.

response.getHeader(name)

Reads out a header that’s already been queued but not sent to the client. Note
that the name is case insensitive. This can only be called before headers get
implicitly flushed.

Example:

  1. var contentType = response.getHeader('content-type');

response.removeHeader(name)

Removes a header that’s queued for implicit sending.

Example:

  1. response.removeHeader("Content-Encoding");

response.write(chunk[, encoding][, callback])

If this method is called and response.writeHead() has not been called,
it will switch to implicit header mode and flush the implicit headers.

This sends a chunk of the response body. This method may
be called multiple times to provide successive parts of the body.

chunk can be a string or a buffer. If chunk is a string,
the second parameter specifies how to encode it into a byte stream.
By default the encoding is 'utf8'. The last parameter callback
will be called when this chunk of data is flushed.

Note: This is the raw HTTP body and has nothing to do with
higher-level multi-part body encodings that may be used.

The first time response.write() is called, it will send the buffered
header information and the first body to the client. The second time
response.write() is called, Node assumes you’re going to be streaming
data, and sends that separately. That is, the response is buffered up to the
first chunk of body.

Returns true if the entire data was flushed successfully to the kernel
buffer. Returns false if all or part of the data was queued in user memory.
'drain' will be emitted when the buffer is free again.

response.addTrailers(headers)

This method adds HTTP trailing headers (a header but at the end of the
message) to the response.

Trailers will only be emitted if chunked encoding is used for the
response; if it is not (e.g., if the request was HTTP/1.0), they will
be silently discarded.

Note that HTTP requires the Trailer header to be sent if you intend to
emit trailers, with a list of the header fields in its value. E.g.,

  1. response.writeHead(200, { 'Content-Type': 'text/plain',
  2.                           'Trailer': 'Content-MD5' });
  3. response.write(fileData);
  4. response.addTrailers({'Content-MD5': "7895bf4b8828b55ceaf47747b4bca667"});
  5. response.end();

response.end([data][, encoding][, callback])

This method signals to the server that all of the response headers and body
have been sent; that server should consider this message complete.
The method, response.end(), MUST be called on each
response.

If data is specified, it is equivalent to calling
response.write(data, encoding) followed by response.end(callback).

If callback is specified, it will be called when the response stream
is finished.

http.request(options[, callback])

Node maintains several connections per server to make HTTP requests.
This function allows one to transparently issue requests.

options can be an object or a string. If options is a string, it is
automatically parsed with url.parse().

Options:

  • host: A domain name or IP address of the server to issue the request to.
    Defaults to 'localhost'.
  • hostname: To support url.parse() hostname is preferred over host
  • port: Port of remote server. Defaults to 80.
  • localAddress: Local interface to bind for network connections.
  • socketPath: Unix Domain Socket (use one of host:port or socketPath)
  • method: A string specifying the HTTP request method. Defaults to 'GET'.
  • path: Request path. Defaults to '/'. Should include query string if any.
    E.G. '/index.html?page=12'. An exception is thrown when the request path
    contains illegal characters. Currently, only spaces are rejected but that
    may change in the future.
  • headers: An object containing request headers.
  • auth: Basic authentication i.e. 'user:password' to compute an
    Authorization header.
  • agent: Controls Agent behavior. When an Agent is used request will
    default to Connection: keep-alive. Possible values:
    • undefined (default): use global Agent for this host and port.
    • Agent object: explicitly use the passed in Agent.
    • false: opts out of connection pooling with an Agent, defaults request to
      Connection: close.
  • keepAlive: {Boolean} Keep sockets around in a pool to be used
    by other requests in the future. Default = false
  • keepAliveMsecs: {Integer} When using HTTP KeepAlive, how often to
    send TCP KeepAlive packets over sockets being kept alive. Default =
    1000. Only relevant if keepAlive is set to true.

The optional callback parameter will be added as a one time listener for
the ‘response’ event.

http.request() returns an instance of the http.ClientRequest
class. The ClientRequest instance is a writable stream. If one needs to
upload a file with a POST request, then write to the ClientRequest object.

Example:

  1. var postData = querystring.stringify({
  2.   'msg' : 'Hello World!'
  3. });
  5. var options = {
  6.   hostname: 'www.google.com',
  7.   port: 80,
  8.   path: '/upload',
  9.   method: 'POST',
  10.   headers: {
  11.     'Content-Type': 'application/x-www-form-urlencoded',
  12.     'Content-Length': postData.length
  13.   }
  14. };
  16. var req = http.request(options, function(res) {
  17.   console.log('STATUS: ' + res.statusCode);
  18.   console.log('HEADERS: ' + JSON.stringify(res.headers));
  19.   res.setEncoding('utf8');
  20.   var data = '';
  21.   res.on('data', function (chunk) {
  22.     console.log('PARTIAL BODY: ' + chunk);
  23.     data += chunk;
  24.   });
  25.   res.on('end', function() {
  26.     console.log('COMPLETE BODY: ' + data);  
  27.   });
  28. });
  30. req.on('error', function(e) {
  31.   console.log('problem with request: ' + e.message);
  32. });
  34. // write data to request body
  35. req.write(postData);
  36. req.end();

The res object handed off to the callback function passed into to
http.request is an instance of http.IncomingMessage, which is an
instance of a Readable Stream. The content of a successful response will be
delivered using zero or more data events followed by a closing end
event.

Note that in the example req.end() was called. With http.request() one
must always call req.end() to signify that you’re done with the request -
even if there is no data being written to the request body.

If any error is encountered during the request (be that with DNS resolution,
TCP level errors, or actual HTTP parse errors) an 'error' event is emitted
on the returned request object.

There are a few special headers that should be noted.

  • Sending a ‘Connection: keep-alive’ will notify Node that the connection to
    the server should be persisted until the next request.

  • Sending a ‘Content-length’ header will disable the default chunked encoding.

  • Sending an ‘Expect’ header will immediately send the request headers.
    Usually, when sending ‘Expect: 100-continue’, you should both set a timeout
    and listen for the continue event. See RFC2616 Section 8.2.3 for more
    information.

  • Sending an Authorization header will override using the auth option
    to compute basic authentication.

http.get(options[, callback])

Since most requests are GET requests without bodies, Node provides this
convenience method. The only difference between this method and http.request()
is that it sets the method to GET and calls req.end() automatically.

Example:

  1. http.get("http://www.google.com/index.html", function(res) {
  2.   console.log("Got response: " + res.statusCode);
  3.   // consume response body
  4.   res.resume();
  5. }).on('error', function(e) {
  6.   console.log("Got error: " + e.message);
  7. });

Class: http.Agent

The HTTP Agent is used for pooling sockets used in HTTP client
requests.

The HTTP Agent also defaults client requests to using
Connection:keep-alive. If no pending HTTP requests are waiting on a
socket to become free the socket is closed. This means that Node’s
pool has the benefit of keep-alive when under load but still does not
require developers to manually close the HTTP clients using
KeepAlive.

If you opt into using HTTP KeepAlive, you can create an Agent object
with that flag set to true. (See the constructor
options below.) Then, the Agent will keep
unused sockets in a pool for later use. They will be explicitly
marked so as to not keep the Node process running. However, it is
still a good idea to explicitly destroy()
KeepAlive agents when they are no longer in use, so that the Sockets
will be shut down.

Sockets are removed from the agent’s pool when the socket emits either
a “close” event or a special “agentRemove” event. This means that if
you intend to keep one HTTP request open for a long time and don’t
want it to stay in the pool you can do something along the lines of:

  1. http.get(options, function(res) {
  2.   // Do stuff
  3. }).on("socket", function (socket) {
  4.   socket.emit("agentRemove");
  5. });

Alternatively, you could just opt out of pooling entirely using
agent:false:

  1. http.get({
  2.   hostname: 'localhost',
  3.   port: 80,
  4.   path: '/',
  5.   agent: false  // create a new agent just for this one request
  6. }, function (res) {
  7.   // Do stuff with response
  8. })

new Agent([options])

  • options {Object} Set of configurable options to set on the agent.
    Can have the following fields:
    • keepAlive {Boolean} Keep sockets around in a pool to be used by
      other requests in the future. Default = false
    • keepAliveMsecs {Integer} When using HTTP KeepAlive, how often
      to send TCP KeepAlive packets over sockets being kept alive.
      Default = 1000. Only relevant if keepAlive is set to true.
    • maxSockets {Number} Maximum number of sockets to allow per
      host. Default = Infinity.
    • maxFreeSockets {Number} Maximum number of sockets to leave open
      in a free state. Only relevant if keepAlive is set to true.
      Default = 256.

The default http.globalAgent that is used by http.request has all
of these values set to their respective defaults.

To configure any of them, you must create your own Agent object.

  1. var http = require('http');
  2. var keepAliveAgent = new http.Agent({ keepAlive: true });
  3. options.agent = keepAliveAgent;
  4. http.request(options, onResponseCallback);

agent.maxSockets

By default set to Infinity. Determines how many concurrent sockets the agent
can have open per origin. Origin is either a ‘host:port’ or
‘host:port:localAddress’ combination.

agent.maxFreeSockets

By default set to 256. For Agents supporting HTTP KeepAlive, this
sets the maximum number of sockets that will be left open in the free
state.

agent.sockets

An object which contains arrays of sockets currently in use by the
Agent. Do not modify.

agent.freeSockets

An object which contains arrays of sockets currently awaiting use by
the Agent when HTTP KeepAlive is used. Do not modify.

agent.requests

An object which contains queues of requests that have not yet been assigned to
sockets. Do not modify.

agent.destroy()

Destroy any sockets that are currently in use by the agent.

It is usually not necessary to do this. However, if you are using an
agent with KeepAlive enabled, then it is best to explicitly shut down
the agent when you know that it will no longer be used. Otherwise,
sockets may hang open for quite a long time before the server
terminates them.

agent.getName(options)

Get a unique name for a set of request options, to determine whether a
connection can be reused. In the http agent, this returns
host:port:localAddress. In the https agent, the name includes the
CA, cert, ciphers, and other HTTPS/TLS-specific options that determine
socket reusability.

http.globalAgent

Global instance of Agent which is used as the default for all http client
requests.

Class: http.ClientRequest

This object is created internally and returned from http.request(). It
represents an in-progress request whose header has already been queued. The
header is still mutable using the setHeader(name, value), getHeader(name),
removeHeader(name) API. The actual header will be sent along with the first
data chunk or when closing the connection.

To get the response, add a listener for 'response' to the request object.
'response' will be emitted from the request object when the response
headers have been received. The 'response' event is executed with one
argument which is an instance of http.IncomingMessage.

During the 'response' event, one can add listeners to the
response object; particularly to listen for the 'data' event.

If no 'response' handler is added, then the response will be
entirely discarded. However, if you add a 'response' event handler,
then you must consume the data from the response object, either by
calling response.read() whenever there is a 'readable' event, or
by adding a 'data' handler, or by calling the .resume() method.
Until the data is consumed, the 'end' event will not fire. Also, until
the data is read it will consume memory that can eventually lead to a
‘process out of memory’ error.

Note: Node does not check whether Content-Length and the length of the body
which has been transmitted are equal or not.

The request implements the Writable Stream interface. This is an
EventEmitter with the following events:

Event: ‘response’

function (response) { }

Emitted when a response is received to this request. This event is emitted only
once. The response argument will be an instance of http.IncomingMessage.

Options:

  • host: A domain name or IP address of the server to issue the request to.
  • port: Port of remote server.
  • socketPath: Unix Domain Socket (use one of host:port or socketPath)

Event: ‘socket’

function (socket) { }

Emitted after a socket is assigned to this request.

Event: ‘connect’

function (response, socket, head) { }

Emitted each time a server responds to a request with a CONNECT method. If this
event isn’t being listened for, clients receiving a CONNECT method will have
their connections closed.

A client server pair that show you how to listen for the connect event.

  1. var http = require('http');
  2. var net = require('net');
  3. var url = require('url');
  5. // Create an HTTP tunneling proxy
  6. var proxy = http.createServer(function (req, res) {
  7.   res.writeHead(200, {'Content-Type': 'text/plain'});
  8.   res.end('okay');
  9. });
  10. proxy.on('connect', function(req, cltSocket, head) {
  11.   // connect to an origin server
  12.   var srvUrl = url.parse('http://' + req.url);
  13.   var srvSocket = net.connect(srvUrl.port, srvUrl.hostname, function() {
  14.     cltSocket.write('HTTP/1.1 200 Connection Established\r\n' +
  15.                     'Proxy-agent: Node-Proxy\r\n' +
  16.                     '\r\n');
  17.     srvSocket.write(head);
  18.     srvSocket.pipe(cltSocket);
  19.     cltSocket.pipe(srvSocket);
  20.   });
  21. });
  23. // now that proxy is running
  24. proxy.listen(1337, '127.0.0.1', function() {
  26.   // make a request to a tunneling proxy
  27.   var options = {
  28.     port: 1337,
  29.     hostname: '127.0.0.1',
  30.     method: 'CONNECT',
  31.     path: 'www.google.com:80'
  32.   };
  34.   var req = http.request(options);
  35.   req.end();
  37.   req.on('connect', function(res, socket, head) {
  38.     console.log('got connected!');
  40.     // make a request over an HTTP tunnel
  41.     socket.write('GET / HTTP/1.1\r\n' +
  42.                  'Host: www.google.com:80\r\n' +
  43.                  'Connection: close\r\n' +
  44.                  '\r\n');
  45.     socket.on('data', function(chunk) {
  46.       console.log(chunk.toString());
  47.     });
  48.     socket.on('end', function() {
  49.       proxy.close();
  50.     });
  51.   });
  52. });

Event: ‘upgrade’

function (response, socket, head) { }

Emitted each time a server responds to a request with an upgrade. If this
event isn’t being listened for, clients receiving an upgrade header will have
their connections closed.

A client server pair that show you how to listen for the upgrade event.

  1. var http = require('http');
  3. // Create an HTTP server
  4. var srv = http.createServer(function (req, res) {
  5.   res.writeHead(200, {'Content-Type': 'text/plain'});
  6.   res.end('okay');
  7. });
  8. srv.on('upgrade', function(req, socket, head) {
  9.   socket.write('HTTP/1.1 101 Web Socket Protocol Handshake\r\n' +
  10.                'Upgrade: WebSocket\r\n' +
  11.                'Connection: Upgrade\r\n' +
  12.                '\r\n');
  14.   socket.pipe(socket); // echo back
  15. });
  17. // now that server is running
  18. srv.listen(1337, '127.0.0.1', function() {
  20.   // make a request
  21.   var options = {
  22.     port: 1337,
  23.     hostname: '127.0.0.1',
  24.     headers: {
  25.       'Connection': 'Upgrade',
  26.       'Upgrade': 'websocket'
  27.     }
  28.   };
  30.   var req = http.request(options);
  31.   req.end();
  33.   req.on('upgrade', function(res, socket, upgradeHead) {
  34.     console.log('got upgraded!');
  35.     socket.end();
  36.     process.exit(0);
  37.   });
  38. });

Event: ‘continue’

function () { }

Emitted when the server sends a ‘100 Continue’ HTTP response, usually because
the request contained ‘Expect: 100-continue’. This is an instruction that
the client should send the request body.

request.flushHeaders()

Flush the request headers.

For efficiency reasons, node.js normally buffers the request headers until you
call request.end() or write the first chunk of request data. It then tries
hard to pack the request headers and data into a single TCP packet.

That’s usually what you want (it saves a TCP round-trip) but not when the first
data isn’t sent until possibly much later. request.flush() lets you bypass
the optimization and kickstart the request.

request.write(chunk[, encoding][, callback])

Sends a chunk of the body. By calling this method
many times, the user can stream a request body to a
server—in that case it is suggested to use the
['Transfer-Encoding', 'chunked'] header line when
creating the request.

The chunk argument should be a Buffer or a string.

The encoding argument is optional and only applies when chunk is a string.
Defaults to 'utf8'.

The callback argument is optional and will be called when this chunk of data
is flushed.

request.end([data][, encoding][, callback])

Finishes sending the request. If any parts of the body are
unsent, it will flush them to the stream. If the request is
chunked, this will send the terminating '0\r\n\r\n'.

If data is specified, it is equivalent to calling
request.write(data, encoding) followed by request.end(callback).

If callback is specified, it will be called when the request stream
is finished.

request.abort()

Marks the request as aborting. Calling this will cause remaining data
in the response to be dropped and the socket to be destroyed.

request.setTimeout(timeout[, callback])

Once a socket is assigned to this request and is connected
socket.setTimeout() will be called.

request.setNoDelay([noDelay])

Once a socket is assigned to this request and is connected
socket.setNoDelay() will be called.

request.setSocketKeepAlive([enable][, initialDelay])

Once a socket is assigned to this request and is connected
socket.setKeepAlive() will be called.

http.IncomingMessage

An IncomingMessage object is created by http.Server or
http.ClientRequest and passed as the first argument to the 'request'
and 'response' event respectively. It may be used to access response status,
headers and data.

It implements the Readable Stream interface, as well as the
following additional events, methods, and properties.

Event: ‘close’

function () { }

Indicates that the underlying connection was closed.
Just like 'end', this event occurs only once per response.

message.httpVersion

In case of server request, the HTTP version sent by the client. In the case of
client response, the HTTP version of the connected-to server.
Probably either '1.1' or '1.0'.

Also response.httpVersionMajor is the first integer and
response.httpVersionMinor is the second.

message.headers

The request/response headers object.

Read only map of header names and values. Header names are lower-cased.
Example:

  1. // Prints something like:
  2. //
  3. // { 'user-agent': 'curl/7.22.0',
  4. //   host: '127.0.0.1:8000',
  5. //   accept: '*/*' }
  6. console.log(request.headers);

message.rawHeaders

The raw request/response headers list exactly as they were received.

Note that the keys and values are in the same list. It is not a
list of tuples. So, the even-numbered offsets are key values, and the
odd-numbered offsets are the associated values.

Header names are not lowercased, and duplicates are not merged.

  1. // Prints something like:
  2. //
  3. // [ 'user-agent',
  4. //   'this is invalid because there can be only one',
  5. //   'User-Agent',
  6. //   'curl/7.22.0',
  7. //   'Host',
  8. //   '127.0.0.1:8000',
  9. //   'ACCEPT',
  10. //   '*/*' ]
  11. console.log(request.rawHeaders);

message.trailers

The request/response trailers object. Only populated at the ‘end’ event.

message.rawTrailers

The raw request/response trailer keys and values exactly as they were
received. Only populated at the ‘end’ event.

message.setTimeout(msecs, callback)

  • msecs {Number}
  • callback {Function}

Calls message.connection.setTimeout(msecs, callback).

message.method

Only valid for request obtained from http.Server.

The request method as a string. Read only. Example:
'GET', 'DELETE'.

message.url

Only valid for request obtained from http.Server.

Request URL string. This contains only the URL that is
present in the actual HTTP request. If the request is:

  1. GET /status?name=ryan HTTP/1.1\r\n
  2. Accept: text/plain\r\n
  3. \r\n

Then request.url will be:

  1. '/status?name=ryan'

If you would like to parse the URL into its parts, you can use
require('url').parse(request.url). Example:

  1. node> require('url').parse('/status?name=ryan')
  2. { href: '/status?name=ryan',
  3.   search: '?name=ryan',
  4.   query: 'name=ryan',
  5.   pathname: '/status' }

If you would like to extract the params from the query string,
you can use the require('querystring').parse function, or pass
true as the second argument to require('url').parse. Example:

  1. node> require('url').parse('/status?name=ryan', true)
  2. { href: '/status?name=ryan',
  3.   search: '?name=ryan',
  4.   query: { name: 'ryan' },
  5.   pathname: '/status' }

message.statusCode

Only valid for response obtained from http.ClientRequest.

The 3-digit HTTP response status code. E.G. 404.

message.statusMessage

Only valid for response obtained from http.ClientRequest.

The HTTP response status message (reason phrase). E.G. OK or Internal Server Error.

message.socket

The net.Socket object associated with the connection.

With HTTPS support, use request.connection.verifyPeer() and
request.connection.getPeerCertificate() to obtain the client’s
authentication details.