@ -1,8 +1,11 @@
import dotenv from 'dotenv'
import express from 'express'
import http from 'http'
import redis from 'redis'
import pg from 'pg'
import log from 'npmlog'
import url from 'url'
import WebSocket from 'ws'
const env = process . env . NODE _ENV || 'development'
@ -27,8 +30,10 @@ const pgConfigs = {
}
}
const app = express ( )
const app = express ( )
const pgPool = new pg . Pool ( pgConfigs [ env ] )
const server = http . createServer ( app )
const wss = new WebSocket . Server ( { server } )
const allowCrossDomain = ( req , res , next ) => {
res . header ( 'Access-Control-Allow-Origin' , '*' )
@ -38,22 +43,7 @@ const allowCrossDomain = (req, res, next) => {
next ( )
}
const authenticationMiddleware = ( req , res , next ) => {
if ( req . method === 'OPTIONS' ) {
return next ( )
}
const authorization = req . get ( 'Authorization' )
if ( ! authorization ) {
const err = new Error ( 'Missing access token' )
err . statusCode = 401
return next ( err )
}
const token = authorization . replace ( /^Bearer / , '' )
const accountFromToken = ( token , req , next ) => {
pgPool . connect ( ( err , client , done ) => {
if ( err ) {
return next ( err )
@ -80,26 +70,36 @@ const authenticationMiddleware = (req, res, next) => {
} )
}
const authenticationMiddleware = ( req , res , next ) => {
if ( req . method === 'OPTIONS' ) {
return next ( )
}
const authorization = req . get ( 'Authorization' )
if ( ! authorization ) {
const err = new Error ( 'Missing access token' )
err . statusCode = 401
return next ( err )
}
const token = authorization . replace ( /^Bearer / , '' )
accountFromToken ( token , req , next )
}
const errorMiddleware = ( err , req , res , next ) => {
log . error ( err )
res . writeHead ( err . statusCode || 500 , { 'Content-Type' : 'application/json' } )
res . end ( JSON . stringify ( { error : err . statusCode ? ` ${ err } ` : 'An unexpected error occured' } ) )
res . end ( JSON . stringify ( { error : err . statusCode ? ` ${ err } ` : 'An unexpected error occur r ed' } ) )
}
const placeholders = ( arr , shift = 0 ) => arr . map ( ( _ , i ) => ` $ ${ i + 1 + shift } ` ) . join ( ', ' ) ;
const streamFrom = ( id , req , res , needsFiltering = false ) => {
const streamFrom = ( redisClient, id , req , output , needsFiltering = false ) => {
log . verbose ( ` Starting stream from ${ id } for ${ req . accountId } ` )
res . setHeader ( 'Content-Type' , 'text/event-stream' )
res . setHeader ( 'Transfer-Encoding' , 'chunked' )
const redisClient = redis . createClient ( {
host : process . env . REDIS _HOST || '127.0.0.1' ,
port : process . env . REDIS _PORT || 6379 ,
password : process . env . REDIS _PASSWORD
} )
redisClient . on ( 'message' , ( channel , message ) => {
const { event , payload } = JSON . parse ( message )
@ -127,36 +127,107 @@ const streamFrom = (id, req, res, needsFiltering = false) => {
return
}
res. write ( ` event: ${ event } \n ` )
res. write ( ` data: ${ payload } \n \n ` )
log. silly ( ` Transmitting for ${ req . accountId } : ${ event } ${ payload } ` )
output( event , payload )
} )
} )
} else {
res. write ( ` event: ${ event } \n ` )
res. write ( ` data: ${ payload } \n \n ` )
log. silly ( ` Transmitting for ${ req . accountId } : ${ event } ${ payload } ` )
output( event , payload )
}
} )
redisClient . subscribe ( id )
}
// Setup stream output to HTTP
const streamToHttp = ( req , res , redisClient ) => {
res . setHeader ( 'Content-Type' , 'text/event-stream' )
res . setHeader ( 'Transfer-Encoding' , 'chunked' )
const heartbeat = setInterval ( ( ) => res . write ( ':thump\n' ) , 15000 )
req . on ( 'close' , ( ) => {
log . verbose ( ` Ending stream from ${ id } for ${ req . accountId } ` )
log . verbose ( ` Ending stream f or ${ req . accountId } ` )
clearInterval ( heartbeat )
redisClient . quit ( )
} )
redisClient . subscribe ( id )
return ( event , payload ) => {
res . write ( ` event: ${ event } \n ` )
res . write ( ` data: ${ payload } \n \n ` )
}
}
// Setup stream output to WebSockets
const streamToWs = ( req , ws , redisClient ) => {
ws . on ( 'close' , ( ) => {
log . verbose ( ` Ending stream for ${ req . accountId } ` )
redisClient . quit ( )
} )
return ( event , payload ) => {
ws . send ( JSON . stringify ( { event , payload } ) )
}
}
// Get new redis connection
const getRedisClient = ( ) => redis . createClient ( {
host : process . env . REDIS _HOST || '127.0.0.1' ,
port : process . env . REDIS _PORT || 6379 ,
password : process . env . REDIS _PASSWORD
} )
app . use ( allowCrossDomain )
app . use ( authenticationMiddleware )
app . use ( errorMiddleware )
app . get ( '/api/v1/streaming/user' , ( req , res ) => streamFrom ( ` timeline: ${ req . accountId } ` , req , res ) )
app . get ( '/api/v1/streaming/public' , ( req , res ) => streamFrom ( 'timeline:public' , req , res , true ) )
app . get ( '/api/v1/streaming/hashtag' , ( req , res ) => streamFrom ( ` timeline:hashtag: ${ req . params . tag } ` , req , res , true ) )
app . get ( '/api/v1/streaming/user' , ( req , res ) => {
const redisClient = getRedisClient ( )
streamFrom ( redisClient , ` timeline: ${ req . accountId } ` , req , streamToHttp ( req , res , redisClient ) )
} )
app . get ( '/api/v1/streaming/public' , ( req , res ) => {
const redisClient = getRedisClient ( )
streamFrom ( redisClient , 'timeline:public' , req , streamToHttp ( req , res , redisClient ) , true )
} )
app . get ( '/api/v1/streaming/hashtag' , ( req , res ) => {
const redisClient = getRedisClient ( )
streamFrom ( redisClient , ` timeline:hashtag: ${ req . params . tag } ` , req , streamToHttp ( req , res , redisClient ) , true )
} )
log . level = 'verbose'
log . info ( ` Starting HTTP server on port ${ process . env . PORT || 4000 } ` )
wss . on ( 'connection' , ws => {
const location = url . parse ( ws . upgradeReq . url , true )
const token = location . query . access _token
const req = { }
app . listen ( process . env . PORT || 4000 )
accountFromToken ( token , req , err => {
if ( err ) {
log . error ( err )
ws . close ( )
return
}
const redisClient = getRedisClient ( )
switch ( location . query . stream ) {
case 'user' :
streamFrom ( redisClient , ` timeline: ${ req . accountId } ` , req , streamToWs ( req , ws , redisClient ) )
break ;
case 'public' :
streamFrom ( redisClient , 'timeline:public' , req , streamToWs ( req , ws , redisClient ) , true )
break ;
case 'hashtag' :
streamFrom ( redisClient , ` timeline:hashtag: ${ location . query . tag } ` , req , streamToWs ( req , ws , redisClient ) , true )
break ;
default :
ws . close ( )
}
} )
} )
server . listen ( process . env . PORT || 4000 , ( ) => {
log . level = process . env . LOG _LEVEL || 'verbose'
log . info ( ` Starting streaming API server on port ${ server . address ( ) . port } ` )
} )
Eugen Rochko
8 years ago