Add an option `event_headers_style` to PostAgent
It is defaulted to `capitalized`, normalizing emitted headers by
capitalizing the names so downstream agents don't need to bother with
the letter cases.
Previously, the style of header names in an emitted event would vary
depending on the server and the backend HTTP library. Most notably, the
`net_http` backend downcases header names whereas other backends do not.
For backward compatibility, preexisting PostAgents are automatically
configured to have `event_headers_style` set to `raw` via migration.
Akinori MUSHA
共有 3 个文件被更改，包括 72 次插入 和 3 次删除
+ 41
- 1
app/models/agents/post_agent.rb
@@ -25,6 +25,13 @@ module Agents |
||
| 25 | 25 |
|
| 26 | 26 |
If `emit_events` is set to `true`, the server response will be emitted as an Event and can be fed to a WebsiteAgent for parsing (using its `data_from_event` and `type` options). No data processing |
| 27 | 27 |
will be attempted by this Agent, so the Event's "body" value will always be raw text. |
| 28 |
+ The Event will also have a "headers" hash and a "status" integer value. |
|
| 29 |
+ Set `event_headers_style` to one of the following values to normalize the keys of "headers" for downstream agents' convenience: |
|
| 30 |
+ |
|
| 31 |
+ * `capitalized` (default) - Header names are capitalized; e.g. "Content-Type" |
|
| 32 |
+ * `downcased` - Header names are downcased; e.g. "content-type" |
|
| 33 |
+ * `snakecased` - Header names are snakecased; e.g. "content_type" |
|
| 34 |
+ * `raw` - Backward compatibility option to leave them unmodified from what the underlying HTTP library returns. |
|
| 28 | 35 |
|
| 29 | 36 |
Other Options: |
| 30 | 37 |
|
@@ -92,6 +99,12 @@ module Agents |
||
| 92 | 99 |
errors.add(:base, "if provided, emit_events must be true or false") |
| 93 | 100 |
end |
| 94 | 101 |
|
| 102 |
+ begin |
|
| 103 |
+ normalize_response_headers({})
|
|
| 104 |
+ rescue ArgumentError => e |
|
| 105 |
+ errors.add(:base, e.message) |
|
| 106 |
+ end |
|
| 107 |
+ |
|
| 95 | 108 |
unless %w[post get put delete patch].include?(method) |
| 96 | 109 |
errors.add(:base, "method must be 'post', 'get', 'put', 'delete', or 'patch'") |
| 97 | 110 |
end |
@@ -124,6 +137,29 @@ module Agents |
||
| 124 | 137 |
|
| 125 | 138 |
private |
| 126 | 139 |
|
| 140 |
+ def normalize_response_headers(headers) |
|
| 141 |
+ case interpolated['event_headers_style'] |
|
| 142 |
+ when nil, '', 'capitalized' |
|
| 143 |
+ normalize = ->name {
|
|
| 144 |
+ name.gsub(/(?:\A|(?<=-))([[:alpha:]])|([[:alpha:]]+)/) {
|
|
| 145 |
+ $1 ? $1.upcase : $2.downcase |
|
| 146 |
+ } |
|
| 147 |
+ } |
|
| 148 |
+ when 'downcased' |
|
| 149 |
+ normalize = :downcase.to_proc |
|
| 150 |
+ when 'snakecased', nil |
|
| 151 |
+ normalize = ->name { name.tr('A-Z-', 'a-z_') }
|
|
| 152 |
+ when 'raw' |
|
| 153 |
+ normalize = ->name { name } # :itself.to_proc in Ruby >= 2.2
|
|
| 154 |
+ else |
|
| 155 |
+ raise ArgumentError, "if provided, event_headers_style must be 'capitalized', 'downcased', 'snakecased' or 'raw'" |
|
| 156 |
+ end |
|
| 157 |
+ |
|
| 158 |
+ headers.each_with_object({}) { |(key, value), hash|
|
|
| 159 |
+ hash[normalize[key]] = value |
|
| 160 |
+ } |
|
| 161 |
+ end |
|
| 162 |
+ |
|
| 127 | 163 |
def handle(data, payload = {})
|
| 128 | 164 |
url = interpolated(payload)[:post_url] |
| 129 | 165 |
headers = headers() |
@@ -156,7 +192,11 @@ module Agents |
||
| 156 | 192 |
} |
| 157 | 193 |
|
| 158 | 194 |
if boolify(interpolated['emit_events']) |
| 159 |
- create_event payload: { body: response.body, headers: response.headers, status: response.status }
|
|
| 195 |
+ create_event payload: {
|
|
| 196 |
+ body: response.body, |
|
| 197 |
+ headers: normalize_response_headers(response.headers), |
|
| 198 |
+ status: response.status |
|
| 199 |
+ } |
|
| 160 | 200 |
end |
| 161 | 201 |
end |
| 162 | 202 |
end |
+ 11
- 0
db/migrate/20160405072512_post_agent_set_event_header_style.rb
@@ -0,0 +1,11 @@ |
||
| 1 |
+class PostAgentSetEventHeaderStyle < ActiveRecord::Migration |
|
| 2 |
+ def up |
|
| 3 |
+ Agent.of_type("Agents::PostAgent").each do |post_agent|
|
|
| 4 |
+ if post_agent.send(:boolify, post_agent.options['emit_events']) && |
|
| 5 |
+ !post_agent.options.key?('event_headers_style')
|
|
| 6 |
+ post_agent.options['event_headers_style'] = 'raw' |
|
| 7 |
+ post_agent.save! |
|
| 8 |
+ end |
|
| 9 |
+ end |
|
| 10 |
+ end |
|
| 11 |
+end |
+ 20
- 2
spec/models/agents/post_agent_spec.rb
@@ -52,7 +52,7 @@ describe Agents::PostAgent do |
||
| 52 | 52 |
raise "unexpected Content-Type: #{content_type}"
|
| 53 | 53 |
end |
| 54 | 54 |
end |
| 55 |
- { status: 200, body: "<html>a webpage!</html>", headers: { 'Content-Type' => 'text/html' } }
|
|
| 55 |
+ { status: 200, body: "<html>a webpage!</html>", headers: { 'Content-type' => 'text/html' } }
|
|
| 56 | 56 |
} |
| 57 | 57 |
end |
| 58 | 58 |
|
@@ -226,10 +226,28 @@ describe Agents::PostAgent do |
||
| 226 | 226 |
expect(@checker.events.last.payload['body']).to eq '<html>a webpage!</html>' |
| 227 | 227 |
end |
| 228 | 228 |
|
| 229 |
- it "emits the response headers" do |
|
| 229 |
+ it "emits the response headers capitalized by default" do |
|
| 230 | 230 |
@checker.check |
| 231 | 231 |
expect(@checker.events.last.payload['headers']).to eq({ 'Content-Type' => 'text/html' })
|
| 232 | 232 |
end |
| 233 |
+ |
|
| 234 |
+ it "emits the response headers capitalized" do |
|
| 235 |
+ @checker.options['event_headers_style'] = 'capitalized' |
|
| 236 |
+ @checker.check |
|
| 237 |
+ expect(@checker.events.last.payload['headers']).to eq({ 'Content-Type' => 'text/html' })
|
|
| 238 |
+ end |
|
| 239 |
+ |
|
| 240 |
+ it "emits the response headers downcased" do |
|
| 241 |
+ @checker.options['event_headers_style'] = 'downcased' |
|
| 242 |
+ @checker.check |
|
| 243 |
+ expect(@checker.events.last.payload['headers']).to eq({ 'content-type' => 'text/html' })
|
|
| 244 |
+ end |
|
| 245 |
+ |
|
| 246 |
+ it "emits the response headers snakecased" do |
|
| 247 |
+ @checker.options['event_headers_style'] = 'snakecased' |
|
| 248 |
+ @checker.check |
|
| 249 |
+ expect(@checker.events.last.payload['headers']).to eq({ 'content_type' => 'text/html' })
|
|
| 250 |
+ end |
|
| 233 | 251 |
end |
| 234 | 252 |
end |
| 235 | 253 |
end |