-
Notifications
You must be signed in to change notification settings - Fork 1
/
proxy.js
147 lines (131 loc) · 3.21 KB
/
proxy.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
'use strict'
const _ = require('lodash')
const express = require('express')
const bodyParser = require('body-parser')
const rp = require('request-promise')
const qs = require('qs')
const Feature = require('./feature')
const router = express.Router()
router.use(bodyParser.json())
router.use(bodyParser.urlencoded({extended: true}))
const headerFiller = require('./header-filler')
let proxyHost = ''
function getBaseOpts(req, extraHeaders={}) {
const headers = _.extend(req.headers, extraHeaders)
delete headers['content-length']
return {
method: req.method,
uri: `${proxyHost}${req.path}`,
headers: headers,
resolveWithFullResponse: true
}
}
function getBodyAndType(req) {
const isJsonType = req.headers['content-type'] === 'application/json'
const isBodyJson = typeof req.body === 'object'
const isBodyNotJson = !isBodyJson
const possibleTextBody = isBodyNotJson ? req.body : null
return {
body: isJsonType && isBodyJson ? req.body : possibleTextBody,
json: req.headers['content-type'] === 'application/json'
}
}
function genOpts(feature, req, extraHeaders) {
const baseOpts = getBaseOpts(req, extraHeaders)
switch(feature) {
case Feature.EVENT:
return _.extend(
baseOpts,
{
body: req.body,
json: true
}
)
case Feature.ACTION: {
const payload = req.body.payload
const rawFormBody = qs.stringify({payload: payload}, {format: 'RFC1738'})
return _.extend(
baseOpts,
{
headers: _.extend(baseOpts.headers, {'content-type': 'application/x-www-form-urlencoded'}),
body: rawFormBody
}
)
}
default:
return _.extend(baseOpts, getBodyAndType(req))
}
}
router.all('/slack/*', (req, res) => {
const servingFeature = Feature.byPath(req.path)
headerFiller
.fill(req.body, servingFeature)
.then(headerKVs => {
return _.chain(headerKVs)
.reduce((left, right) => {
return _.extend(left, right)
}).value()
})
.then(extraHeaders => {
return genOpts(servingFeature, req, extraHeaders)
})
.then(options => {
return rp(options)
})
.then(response => {
res
.set(response.headers)
.status(response.statusCode)
.send(response.body)
})
.catch(err => {
try {
res
.set(err.response.headers)
.status(err.response.statusCode)
.send(err.response.body)
}
catch(anotherErr) {
throw err || anotherErr
}
})
.catch(err => {
console.log(err)
res
.status(501)
.send(err)
})
})
router.all('*', (req, res) => {
rp(_.extend(
getBaseOpts(req),
getBodyAndType(req)
))
.then(response => {
res
.set(response.headers)
.status(response.statusCode)
.send(response.body)
})
.catch(err => {
try {
res
.set(err.response.headers)
.status(err.response.statusCode)
.send(err.response.body)
}
catch(anotherErr) {
throw err || anotherErr
}
})
.catch(err => {
console.log(err)
res
.status(501)
.send(err)
})
})
module.exports = _proxyHost => {
proxyHost = _proxyHost
return router
}