-
Notifications
You must be signed in to change notification settings - Fork 789
/
server.rb
292 lines (246 loc) · 8.83 KB
/
server.rb
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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
require 'time'
require 'rack/utils'
module Sprockets
# `Server` is a concern mixed into `Environment` and
# `CachedEnvironment` that provides a Rack compatible `call`
# interface and url generation helpers.
module Server
# `call` implements the Rack 1.x specification which accepts an
# `env` Hash and returns a three item tuple with the status code,
# headers, and body.
#
# Mapping your environment at a url prefix will serve all assets
# in the path.
#
# map "/assets" do
# run Sprockets::Environment.new
# end
#
# A request for `"/assets/foo/bar.js"` will search your
# environment for `"foo/bar.js"`.
def call(env)
start_time = Time.now.to_f
time_elapsed = lambda { ((Time.now.to_f - start_time) * 1000).to_i }
if !['GET', 'HEAD'].include?(env['REQUEST_METHOD'])
return method_not_allowed_response
end
msg = "Served asset #{env['PATH_INFO']} -"
# Extract the path from everything after the leading slash
path = Rack::Utils.unescape(env['PATH_INFO'].to_s.sub(/^\//, ''))
# Strip fingerprint
if fingerprint = path_fingerprint(path)
path = path.sub("-#{fingerprint}", '')
end
# URLs containing a `".."` are rejected for security reasons.
if forbidden_request?(path)
return forbidden_response(env)
end
# Look up the asset.
options = {}
options[:pipeline] = :self if body_only?(env)
asset = find_asset(path, options)
# 2.x/3.x compatibility hack. Just ignore fingerprints on ?body=1 requests.
# 3.x/4.x prefers strong validation of fingerprint to body contents, but
# 2.x just ignored it.
if asset && parse_asset_uri(asset.uri)[1][:pipeline] == "self"
fingerprint = nil
end
if fingerprint
if_match = fingerprint
elsif env['HTTP_IF_MATCH']
if_match = env['HTTP_IF_MATCH'][/^"(\w+)"$/, 1]
end
if env['HTTP_IF_NONE_MATCH']
if_none_match = env['HTTP_IF_NONE_MATCH'][/^"(\w+)"$/, 1]
end
if asset.nil?
status = :not_found
elsif fingerprint && asset.etag != fingerprint
status = :not_found
elsif if_match && asset.etag != if_match
status = :precondition_failed
elsif if_none_match && asset.etag == if_none_match
status = :not_modified
else
status = :ok
end
case status
when :ok
logger.info "#{msg} 200 OK (#{time_elapsed.call}ms)"
ok_response(asset, env)
when :not_modified
logger.info "#{msg} 304 Not Modified (#{time_elapsed.call}ms)"
not_modified_response(env, if_none_match)
when :not_found
logger.info "#{msg} 404 Not Found (#{time_elapsed.call}ms)"
not_found_response(env)
when :precondition_failed
logger.info "#{msg} 412 Precondition Failed (#{time_elapsed.call}ms)"
precondition_failed_response(env)
end
rescue Exception => e
logger.error "Error compiling asset #{path}:"
logger.error "#{e.class.name}: #{e.message}"
case File.extname(path)
when ".js"
# Re-throw JavaScript asset exceptions to the browser
logger.info "#{msg} 500 Internal Server Error\n\n"
return javascript_exception_response(e)
when ".css"
# Display CSS asset exceptions in the browser
logger.info "#{msg} 500 Internal Server Error\n\n"
return css_exception_response(e)
else
raise
end
end
private
def forbidden_request?(path)
# Prevent access to files elsewhere on the file system
#
# http://example.org/assets/../../../etc/passwd
#
path.include?("..") || absolute_path?(path) || path.include?("://")
end
def head_request?(env)
env['REQUEST_METHOD'] == 'HEAD'
end
# Returns a 200 OK response tuple
def ok_response(asset, env)
if head_request?(env)
[ 200, headers(env, asset, 0), [] ]
else
[ 200, headers(env, asset, asset.length), asset ]
end
end
# Returns a 304 Not Modified response tuple
def not_modified_response(env, etag)
[ 304, cache_headers(env, etag), [] ]
end
# Returns a 403 Forbidden response tuple
def forbidden_response(env)
if head_request?(env)
[ 403, { "Content-Type" => "text/plain", "Content-Length" => "0" }, [] ]
else
[ 403, { "Content-Type" => "text/plain", "Content-Length" => "9" }, [ "Forbidden" ] ]
end
end
# Returns a 404 Not Found response tuple
def not_found_response(env)
if head_request?(env)
[ 404, { "Content-Type" => "text/plain", "Content-Length" => "0", "X-Cascade" => "pass" }, [] ]
else
[ 404, { "Content-Type" => "text/plain", "Content-Length" => "9", "X-Cascade" => "pass" }, [ "Not found" ] ]
end
end
def method_not_allowed_response
[ 405, { "Content-Type" => "text/plain", "Content-Length" => "18" }, [ "Method Not Allowed" ] ]
end
def precondition_failed_response(env)
if head_request?(env)
[ 412, { "Content-Type" => "text/plain", "Content-Length" => "0", "X-Cascade" => "pass" }, [] ]
else
[ 412, { "Content-Type" => "text/plain", "Content-Length" => "19", "X-Cascade" => "pass" }, [ "Precondition Failed" ] ]
end
end
# Returns a JavaScript response that re-throws a Ruby exception
# in the browser
def javascript_exception_response(exception)
err = "#{exception.class.name}: #{exception.message}\n (in #{exception.backtrace[0]})"
body = "throw Error(#{err.inspect})"
[ 200, { "Content-Type" => "application/javascript", "Content-Length" => body.bytesize.to_s }, [ body ] ]
end
# Returns a CSS response that hides all elements on the page and
# displays the exception
def css_exception_response(exception)
message = "\n#{exception.class.name}: #{exception.message}"
backtrace = "\n #{exception.backtrace.first}"
body = <<-CSS
html {
padding: 18px 36px;
}
head {
display: block;
}
body {
margin: 0;
padding: 0;
}
body > * {
display: none !important;
}
head:after, body:before, body:after {
display: block !important;
}
head:after {
font-family: sans-serif;
font-size: large;
font-weight: bold;
content: "Error compiling CSS asset";
}
body:before, body:after {
font-family: monospace;
white-space: pre-wrap;
}
body:before {
font-weight: bold;
content: "#{escape_css_content(message)}";
}
body:after {
content: "#{escape_css_content(backtrace)}";
}
CSS
[ 200, { "Content-Type" => "text/css; charset=utf-8", "Content-Length" => body.bytesize.to_s }, [ body ] ]
end
# Escape special characters for use inside a CSS content("...") string
def escape_css_content(content)
content.
gsub('\\', '\\\\005c ').
gsub("\n", '\\\\000a ').
gsub('"', '\\\\0022 ').
gsub('/', '\\\\002f ')
end
# Test if `?body=1` or `body=true` query param is set
def body_only?(env)
env["QUERY_STRING"].to_s =~ /body=(1|t)/
end
def cache_headers(env, etag)
headers = {}
# Set caching headers
headers["Cache-Control"] = "public"
headers["ETag"] = %("#{etag}")
# If the request url contains a fingerprint, set a long
# expires on the response
if path_fingerprint(env["PATH_INFO"])
headers["Cache-Control"] += ", max-age=31536000"
# Otherwise set `must-revalidate` since the asset could be modified.
else
headers["Cache-Control"] += ", must-revalidate"
headers["Vary"] = "Accept-Encoding"
end
headers
end
def headers(env, asset, length)
headers = {}
# Set content length header
headers["Content-Length"] = length.to_s
# Set content type header
if type = asset.content_type
# Set charset param for text/* mime types
if type.start_with?("text/") && asset.charset
type += "; charset=#{asset.charset}"
end
headers["Content-Type"] = type
end
headers.merge(cache_headers(env, asset.etag))
end
# Gets ETag fingerprint.
#
# "foo-0aa2105d29558f3eb790d411d7d8fb66.js"
# # => "0aa2105d29558f3eb790d411d7d8fb66"
#
def path_fingerprint(path)
path[/-([0-9a-f]{7,128})\.[^.]+\z/, 1]
end
end
end