forked from github/docs
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathindex.js
More file actions
169 lines (148 loc) · 6.82 KB
/
index.js
File metadata and controls
169 lines (148 loc) · 6.82 KB
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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
const express = require('express')
const instrument = require('../lib/instrument-middleware')
const haltOnDroppedConnection = require('./halt-on-dropped-connection')
const abort = require('./abort')
const timeout = require('./timeout')
const morgan = require('morgan')
const datadog = require('./connect-datadog')
const rateLimit = require('./rate-limit')
const cors = require('./cors')
const helmet = require('helmet')
const csp = require('./csp')
const cookieParser = require('./cookie-parser')
const csrf = require('./csrf')
const handleCsrfErrors = require('./handle-csrf-errors')
const compression = require('compression')
const disableCachingOnSafari = require('./disable-caching-on-safari')
const setFastlySurrogateKey = require('./set-fastly-surrogate-key')
const setFastlyCacheHeaders = require('./set-fastly-cache-headers')
const catchBadAcceptLanguage = require('./catch-bad-accept-language')
const reqUtils = require('./req-utils')
const recordRedirect = require('./record-redirect')
const connectSlashes = require('connect-slashes')
const handleErrors = require('./handle-errors')
const { NODE_ENV } = process.env
const isDevelopment = NODE_ENV === 'development'
const isTest = NODE_ENV === 'test' || process.env.GITHUB_ACTIONS === 'true'
// Catch unhandled promise rejections and passing them to Express's error handler
// https://medium.com/@Abazhenov/using-async-await-in-express-with-node-8-b8af872c0016
const asyncMiddleware = fn =>
(req, res, next) => {
Promise.resolve(fn(req, res, next)).catch(next)
}
module.exports = function (app) {
// *** Request connection management ***
if (!isTest) app.use(timeout)
app.use(abort)
// *** Development tools ***
app.use(morgan('dev', { skip: (req, res) => !isDevelopment }))
// *** Observability ***
if (process.env.DD_API_KEY) {
app.use(datadog)
}
// *** Early exits ***
// Don't use the proxy's IP, use the requester's for rate limiting
// See https://expressjs.com/en/guide/behind-proxies.html
app.set('trust proxy', 1)
app.use(rateLimit)
app.use(instrument('./handle-invalid-paths'))
app.use(instrument('./handle-next-data-path'))
// *** Security ***
app.use(cors)
app.use(helmet({
// Override referrerPolicy to match the browser's default: "strict-origin-when-cross-origin".
// Helmet now defaults to "no-referrer", which is a problem for our archived assets proxying.
referrerPolicy: {
policy: 'strict-origin-when-cross-origin'
}
}))
app.use(csp) // Must come after helmet
app.use(cookieParser) // Must come before csrf
app.use(express.json()) // Must come before csrf
app.use(csrf)
app.use(handleCsrfErrors) // Must come before regular handle-errors
// *** Headers ***
app.set('etag', false) // We will manage our own ETags if desired
app.use(compression())
app.use(disableCachingOnSafari)
app.use(setFastlySurrogateKey)
app.use(catchBadAcceptLanguage)
// *** Config and context for redirects ***
app.use(reqUtils) // Must come before record-redirect and events
app.use(recordRedirect)
app.use(instrument('./detect-language')) // Must come before context, breadcrumbs, find-page, handle-errors, homepages
app.use(asyncMiddleware(instrument('./context'))) // Must come before early-access-*, handle-redirects
app.use(asyncMiddleware(instrument('./contextualizers/short-versions'))) // Support version shorthands
// *** Redirects, 3xx responses ***
// I ordered these by use frequency
app.use(connectSlashes(false))
app.use(instrument('./redirects/external'))
app.use(instrument('./redirects/help-to-docs'))
app.use(instrument('./redirects/language-code-redirects')) // Must come before contextualizers
app.use(instrument('./redirects/handle-redirects')) // Must come before contextualizers
// *** Config and context for rendering ***
app.use(asyncMiddleware(instrument('./find-page'))) // Must come before archived-enterprise-versions, breadcrumbs, featured-links, products, render-page
app.use(instrument('./block-robots'))
// Check for a dropped connection before proceeding
app.use(haltOnDroppedConnection)
// *** Rendering, 2xx responses ***
// I largely ordered these by use frequency
app.use(asyncMiddleware(instrument('./archived-enterprise-versions-assets'))) // Must come before static/assets
app.use('/dist', express.static('dist', {
index: false,
etag: false,
immutable: true,
lastModified: false,
maxAge: '28 days' // Could be infinite given our fingerprinting
}))
app.use('/assets', express.static('assets', {
index: false,
etag: false,
lastModified: false,
maxAge: '1 day' // Relatively short in case we update images
}))
app.use('/public', express.static('data/graphql', {
index: false,
etag: false,
lastModified: false,
maxAge: '7 days' // A bit longer since releases are more sparse
}))
app.use('/events', asyncMiddleware(instrument('./events')))
app.use('/search', asyncMiddleware(instrument('./search')))
app.use(asyncMiddleware(instrument('./archived-enterprise-versions')))
app.use(instrument('./robots'))
app.use(/(\/.*)?\/early-access$/, instrument('./contextualizers/early-access-links'))
app.use('/categories.json', asyncMiddleware(instrument('./categories-for-support')))
app.use(instrument('./loaderio-verification'))
app.get('/_500', asyncMiddleware(instrument('./trigger-error')))
// Check for a dropped connection before proceeding (again)
app.use(haltOnDroppedConnection)
// *** Preparation for render-page: contextualizers ***
app.use(asyncMiddleware(instrument('./contextualizers/release-notes')))
app.use(instrument('./contextualizers/graphql'))
app.use(instrument('./contextualizers/rest'))
app.use(instrument('./contextualizers/webhooks'))
app.use(asyncMiddleware(instrument('./contextualizers/whats-new-changelog')))
app.use(instrument('./contextualizers/layout'))
app.use(instrument('./contextualizers/current-product-tree'))
app.use(asyncMiddleware(instrument('./contextualizers/generic-toc')))
app.use(asyncMiddleware(instrument('./contextualizers/breadcrumbs')))
app.use(asyncMiddleware(instrument('./contextualizers/early-access-breadcrumbs')))
app.use(asyncMiddleware(instrument('./contextualizers/product-examples')))
app.use(asyncMiddleware(instrument('./dev-toc')))
app.use(asyncMiddleware(instrument('./featured-links')))
app.use(asyncMiddleware(instrument('./learning-track')))
app.use(asyncMiddleware(instrument('./is-next-request')))
// *** Headers for pages only ***
app.use(setFastlyCacheHeaders)
// handle serving NextJS bundled code (/_next/*)
if (process.env.FEATURE_NEXTJS) {
app.use(instrument('./next'))
}
// Check for a dropped connection before proceeding (again)
app.use(haltOnDroppedConnection)
// *** Rendering, must go almost last ***
app.get('/*', asyncMiddleware(instrument('./render-page')))
// *** Error handling, must go last ***
app.use(handleErrors)
}