creating server

 

const http =require('http');

//1: callback function

function rqList(req , res){

}

//1: creating a server

const server1 = http.createServer(rqList);

//second way

const server2 = http.createServer(function(req,res){

})

//third way

const server = http.createServer((req,res)=>{

console.log(req);

})

//listening to a port for request

server.listen(3000);

while requesting to localhost:3000 in a browser we get the following as request:

rajeshwar@rajeshwar:~/Documents/Nodejs/Node-part-2/basics$ node app
<ref *2> IncomingMessage {
_readableState: ReadableState {
objectMode: false,
highWaterMark: 16384,
buffer: BufferList { head: null, tail: null, length: 0 },
length: 0,
pipes: [],
flowing: null,
ended: false,
endEmitted: false,
reading: false,
sync: true,
needReadable: false,
emittedReadable: false,
readableListening: false,
resumeScheduled: false,
paused: true,
errorEmitted: false,
emitClose: true,
autoDestroy: false,
destroyed: false,
defaultEncoding: 'utf8',
awaitDrainWriters: null,
multiAwaitDrain: false,
readingMore: true,
decoder: null,
encoding: null
},
readable: true,
_events: [Object: null prototype] {
end: [Function: resetHeadersTimeoutOnReqEnd]
},
_eventsCount: 1,
_maxListeners: undefined,
socket: <ref *1> Socket {
connecting: false,
_hadError: false,
_parent: null,
_host: null,
_readableState: ReadableState {
objectMode: false,
highWaterMark: 16384,
buffer: BufferList { head: null, tail: null, length: 0 },
length: 0,
pipes: [],
flowing: true,
ended: false,
endEmitted: false,
reading: true,
sync: false,
needReadable: true,
emittedReadable: false,
readableListening: false,
resumeScheduled: false,
paused: false,
errorEmitted: false,
emitClose: false,
autoDestroy: false,
destroyed: false,
defaultEncoding: 'utf8',
awaitDrainWriters: null,
multiAwaitDrain: false,
readingMore: false,
decoder: null,
encoding: null
},
readable: true,
_events: [Object: null prototype] {
end: [Array],
timeout: [Function: socketOnTimeout],
data: [Function: bound socketOnData],
error: [Function: socketOnError],
close: [Array],
drain: [Function: bound socketOnDrain],
resume: [Function: onSocketResume],
pause: [Function: onSocketPause]
},
_eventsCount: 8,
_maxListeners: undefined,
_writableState: WritableState {
objectMode: false,
highWaterMark: 16384,
finalCalled: false,
needDrain: false,
ending: false,
ended: false,
finished: false,
destroyed: false,
decodeStrings: false,
defaultEncoding: 'utf8',
length: 0,
writing: false,
corked: 0,
sync: true,
bufferProcessing: false,
onwrite: [Function: bound onwrite],
writecb: null,
writelen: 0,
bufferedRequest: null,
lastBufferedRequest: null,
pendingcb: 0,
prefinished: false,
errorEmitted: false,
emitClose: false,
autoDestroy: false,
errored: false,
bufferedRequestCount: 0,
corkedRequestsFree: [Object]
},
writable: true,
allowHalfOpen: true,
_sockname: null,
_pendingData: null,
_pendingEncoding: '',
server: Server {
_events: [Object: null prototype],
_eventsCount: 2,
_maxListeners: undefined,
_connections: 1,
_handle: [TCP],
_usingWorkers: false,
_workers: [],
_unref: false,
allowHalfOpen: true,
pauseOnConnect: false,
httpAllowHalfOpen: false,
timeout: 0,
keepAliveTimeout: 5000,
maxHeadersCount: null,
headersTimeout: 40000,
_connectionKey: '6::::3000',
[Symbol(IncomingMessage)]: [Function: IncomingMessage],
[Symbol(ServerResponse)]: [Function: ServerResponse],
[Symbol(asyncId)]: 2
},
_server: Server {
_events: [Object: null prototype],
_eventsCount: 2,
_maxListeners: undefined,
_connections: 1,
_handle: [TCP],
_usingWorkers: false,
_workers: [],
_unref: false,
allowHalfOpen: true,
pauseOnConnect: false,
httpAllowHalfOpen: false,
timeout: 0,
keepAliveTimeout: 5000,
maxHeadersCount: null,
headersTimeout: 40000,
_connectionKey: '6::::3000',
[Symbol(IncomingMessage)]: [Function: IncomingMessage],
[Symbol(ServerResponse)]: [Function: ServerResponse],
[Symbol(asyncId)]: 2
},
parser: HTTPParser {
'0': [Function: parserOnHeaders],
'1': [Function: parserOnHeadersComplete],
'2': [Function: parserOnBody],
'3': [Function: parserOnMessageComplete],
'4': [Function: bound onParserExecute],
_headers: [],
_url: '',
socket: [Circular *1],
incoming: [Circular *2],
outgoing: null,
maxHeaderPairs: 2000,
_consumed: true,
onIncoming: [Function: bound parserOnIncoming],
parsingHeadersStart: 0
},
on: [Function: socketListenerWrap],
addListener: [Function: socketListenerWrap],
prependListener: [Function: socketListenerWrap],
_paused: false,
_httpMessage: ServerResponse {
_events: [Object: null prototype],
_eventsCount: 1,
_maxListeners: undefined,
outputData: [],
outputSize: 0,
writable: true,
_last: false,
chunkedEncoding: false,
shouldKeepAlive: true,
useChunkedEncodingByDefault: true,
sendDate: true,
_removedConnection: false,
_removedContLen: false,
_removedTE: false,
_contentLength: null,
_hasBody: true,
_trailer: '',
finished: false,
_headerSent: false,
socket: [Circular *1],
_header: null,
_onPendingData: [Function: bound updateOutgoingData],
_sent100: false,
_expect_continue: false,
[Symbol(kNeedDrain)]: false,
[Symbol(isCorked)]: false,
[Symbol(kOutHeaders)]: null
},
[Symbol(asyncId)]: 4,
[Symbol(kHandle)]: TCP {
reading: true,
onconnection: null,
_consumed: true,
[Symbol(owner)]: [Circular *1]
},
[Symbol(lastWriteQueueSize)]: 0,
[Symbol(timeout)]: null,
[Symbol(kBuffer)]: null,
[Symbol(kBufferCb)]: null,
[Symbol(kBufferGen)]: null,
[Symbol(kBytesRead)]: 0,
[Symbol(kBytesWritten)]: 0
},
httpVersionMajor: 1,
httpVersionMinor: 1,
httpVersion: '1.1',
complete: false,
headers: {
host: 'localhost:3000',
'user-agent': 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:79.0) Gecko/20100101 Firefox/79.0',
accept: 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
'accept-language': 'en-US,en;q=0.5',
'accept-encoding': 'gzip, deflate',
connection: 'keep-alive',
'upgrade-insecure-requests': '1',
'if-none-match': 'W/"a63-7W/5JBepybRnD9lrCqUXMeXBTms"'
},
rawHeaders: [
'Host',
'localhost:3000',
'User-Agent',
'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:79.0) Gecko/20100101 Firefox/79.0',
'Accept',
'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',
'Accept-Language',
'en-US,en;q=0.5',
'Accept-Encoding',
'gzip, deflate',
'Connection',
'keep-alive',
'Upgrade-Insecure-Requests',
'1',
'If-None-Match',
'W/"a63-7W/5JBepybRnD9lrCqUXMeXBTms"'
],
trailers: {},
rawTrailers: [],
aborted: false,
upgrade: false,
url: '/',
method: 'GET',
statusCode: null,
statusMessage: null,
client: <ref *1> Socket {
connecting: false,
_hadError: false,
_parent: null,
_host: null,
_readableState: ReadableState {
objectMode: false,
highWaterMark: 16384,
buffer: BufferList { head: null, tail: null, length: 0 },
length: 0,
pipes: [],
flowing: true,
ended: false,
endEmitted: false,
reading: true,
sync: false,
needReadable: true,
emittedReadable: false,
readableListening: false,
resumeScheduled: false,
paused: false,
errorEmitted: false,
emitClose: false,
autoDestroy: false,
destroyed: false,
defaultEncoding: 'utf8',
awaitDrainWriters: null,
multiAwaitDrain: false,
readingMore: false,
decoder: null,
encoding: null
},
readable: true,
_events: [Object: null prototype] {
end: [Array],
timeout: [Function: socketOnTimeout],
data: [Function: bound socketOnData],
error: [Function: socketOnError],
close: [Array],
drain: [Function: bound socketOnDrain],
resume: [Function: onSocketResume],
pause: [Function: onSocketPause]
},
_eventsCount: 8,
_maxListeners: undefined,
_writableState: WritableState {
objectMode: false,
highWaterMark: 16384,
finalCalled: false,
needDrain: false,
ending: false,
ended: false,
finished: false,
destroyed: false,
decodeStrings: false,
defaultEncoding: 'utf8',
length: 0,
writing: false,
corked: 0,
sync: true,
bufferProcessing: false,
onwrite: [Function: bound onwrite],
writecb: null,
writelen: 0,
bufferedRequest: null,
lastBufferedRequest: null,
pendingcb: 0,
prefinished: false,
errorEmitted: false,
emitClose: false,
autoDestroy: false,
errored: false,
bufferedRequestCount: 0,
corkedRequestsFree: [Object]
},
writable: true,
allowHalfOpen: true,
_sockname: null,
_pendingData: null,
_pendingEncoding: '',
server: Server {
_events: [Object: null prototype],
_eventsCount: 2,
_maxListeners: undefined,
_connections: 1,
_handle: [TCP],
_usingWorkers: false,
_workers: [],
_unref: false,
allowHalfOpen: true,
pauseOnConnect: false,
httpAllowHalfOpen: false,
timeout: 0,
keepAliveTimeout: 5000,
maxHeadersCount: null,
headersTimeout: 40000,
_connectionKey: '6::::3000',
[Symbol(IncomingMessage)]: [Function: IncomingMessage],
[Symbol(ServerResponse)]: [Function: ServerResponse],
[Symbol(asyncId)]: 2
},
_server: Server {
_events: [Object: null prototype],
_eventsCount: 2,
_maxListeners: undefined,
_connections: 1,
_handle: [TCP],
_usingWorkers: false,
_workers: [],
_unref: false,
allowHalfOpen: true,
pauseOnConnect: false,
httpAllowHalfOpen: false,
timeout: 0,
keepAliveTimeout: 5000,
maxHeadersCount: null,
headersTimeout: 40000,
_connectionKey: '6::::3000',
[Symbol(IncomingMessage)]: [Function: IncomingMessage],
[Symbol(ServerResponse)]: [Function: ServerResponse],
[Symbol(asyncId)]: 2
},
parser: HTTPParser {
'0': [Function: parserOnHeaders],
'1': [Function: parserOnHeadersComplete],
'2': [Function: parserOnBody],
'3': [Function: parserOnMessageComplete],
'4': [Function: bound onParserExecute],
_headers: [],
_url: '',
socket: [Circular *1],
incoming: [Circular *2],
outgoing: null,
maxHeaderPairs: 2000,
_consumed: true,
onIncoming: [Function: bound parserOnIncoming],
parsingHeadersStart: 0
},
on: [Function: socketListenerWrap],
addListener: [Function: socketListenerWrap],
prependListener: [Function: socketListenerWrap],
_paused: false,
_httpMessage: ServerResponse {
_events: [Object: null prototype],
_eventsCount: 1,
_maxListeners: undefined,
outputData: [],
outputSize: 0,
writable: true,
_last: false,
chunkedEncoding: false,
shouldKeepAlive: true,
useChunkedEncodingByDefault: true,
sendDate: true,
_removedConnection: false,
_removedContLen: false,
_removedTE: false,
_contentLength: null,
_hasBody: true,
_trailer: '',
finished: false,
_headerSent: false,
socket: [Circular *1],
_header: null,
_onPendingData: [Function: bound updateOutgoingData],
_sent100: false,
_expect_continue: false,
[Symbol(kNeedDrain)]: false,
[Symbol(isCorked)]: false,
[Symbol(kOutHeaders)]: null
},
[Symbol(asyncId)]: 4,
[Symbol(kHandle)]: TCP {
reading: true,
onconnection: null,
_consumed: true,
[Symbol(owner)]: [Circular *1]
},
[Symbol(lastWriteQueueSize)]: 0,
[Symbol(timeout)]: null,
[Symbol(kBuffer)]: null,
[Symbol(kBufferCb)]: null,
[Symbol(kBufferGen)]: null,
[Symbol(kBytesRead)]: 0,
[Symbol(kBytesWritten)]: 0
},
_consuming: false,
_dumped: false
}

                        Nodejs program life-cycle: