module Agents
class PostAgent < Agent
include WebRequestConcern
MIME_RE = /\A\w+\/.+\z/
can_dry_run!
no_bulk_receive!
default_schedule "never"
description <<-MD
A Post Agent receives events from other agents (or runs periodically), merges those events with the [Liquid-interpolated](https://github.com/cantino/huginn/wiki/Formatting-Events-using-Liquid) contents of `payload`, and sends the results as POST (or GET) requests to a specified url. To skip merging in the incoming event, but still send the interpolated payload, set `no_merge` to `true`.
The `post_url` field must specify where you would like to send requests. Please include the URI scheme (`http` or `https`).
The `method` used can be any of `get`, `post`, `put`, `patch`, and `delete`.
By default, non-GETs will be sent with form encoding (`application/x-www-form-urlencoded`).
Change `content_type` to `json` to send JSON instead.
Change `content_type` to `xml` to send XML, where the name of the root element may be specified using `xml_root`, defaulting to `post`.
When `content_type` contains a [MIME](https://en.wikipedia.org/wiki/Media_type) type, and `payload` is a string, its interpolated value will be sent as a string in the HTTP request's body and the request's `Content-Type` HTTP header will be set to `content_type`. When `payload` is a string `no_merge` has to be set to `true`.
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
will be attempted by this Agent, so the Event's "body" value will always be raw text.
The Event will also have a "headers" hash and a "status" integer value.
Set `event_headers_style` to one of the following values to normalize the keys of "headers" for downstream agents' convenience:
* `capitalized` (default) - Header names are capitalized; e.g. "Content-Type"
* `downcased` - Header names are downcased; e.g. "content-type"
* `snakecased` - Header names are snakecased; e.g. "content_type"
* `raw` - Backward compatibility option to leave them unmodified from what the underlying HTTP library returns.
Other Options:
* `headers` - When present, it should be a hash of headers to send with the request.
* `basic_auth` - Specify HTTP basic auth parameters: `"username:password"`, or `["username", "password"]`.
* `disable_ssl_verification` - Set to `true` to disable ssl verification.
* `user_agent` - A custom User-Agent name (default: "Faraday v#{Faraday::VERSION}").
MD
event_description <<-MD
Events look like this:
{
"status": 200,
"headers": {
"Content-Type": "text/html",
...
},
"body": "<html>Some data...</html>"
}
MD
def default_options
{
'post_url' => "http://www.example.com",
'expected_receive_period_in_days' => '1',
'content_type' => 'form',
'method' => 'post',
'payload' => {
'key' => 'value',
'something' => 'the event contained {{ somekey }}'
},
'headers' => {},
'emit_events' => 'false',
'no_merge' => 'false'
}
end
def working?
last_receive_at && last_receive_at > interpolated['expected_receive_period_in_days'].to_i.days.ago && !recent_error_logs?
end
def method
(interpolated['method'].presence || 'post').to_s.downcase
end
def validate_options
unless options['post_url'].present? && options['expected_receive_period_in_days'].present?
errors.add(:base, "post_url and expected_receive_period_in_days are required fields")
end
if options['payload'].present? && %w[get delete].include?(method) && !options['payload'].is_a?(Hash)
errors.add(:base, "if provided, payload must be a hash")
end
if options['payload'].present? && %w[post put patch].include?(method)
if !options['payload'].is_a?(Hash) && options['content_type'] !~ MIME_RE
errors.add(:base, "if provided, payload must be a hash")
end
if options['content_type'] =~ MIME_RE && options['payload'].is_a?(String) && boolify(options['no_merge']) != true
errors.add(:base, "when the payload is a string, `no_merge` has to be set to `true`")
end
end
if options.has_key?('emit_events') && boolify(options['emit_events']).nil?
errors.add(:base, "if provided, emit_events must be true or false")
end
begin
normalize_response_headers({})
rescue ArgumentError => e
errors.add(:base, e.message)
end
unless %w[post get put delete patch].include?(method)
errors.add(:base, "method must be 'post', 'get', 'put', 'delete', or 'patch'")
end
if options['no_merge'].present? && !%[true false].include?(options['no_merge'].to_s)
errors.add(:base, "if provided, no_merge must be 'true' or 'false'")
end
unless headers.is_a?(Hash)
errors.add(:base, "if provided, headers must be a hash")
end
validate_web_request_options!
end
def receive(incoming_events)
incoming_events.each do |event|
outgoing = interpolated(event)['payload'].presence || {}
if boolify(interpolated['no_merge'])
handle outgoing, event.payload
else
handle outgoing.merge(event.payload), event.payload
end
end
end
def check
handle interpolated['payload'].presence || {}
end
private
def normalize_response_headers(headers)
case interpolated['event_headers_style']
when nil, '', 'capitalized'
normalize = ->name {
name.gsub(/(?:\A|(?<=-))([[:alpha:]])|([[:alpha:]]+)/) {
$1 ? $1.upcase : $2.downcase
}
}
when 'downcased'
normalize = :downcase.to_proc
when 'snakecased', nil
normalize = ->name { name.tr('A-Z-', 'a-z_') }
when 'raw'
normalize = ->name { name } # :itself.to_proc in Ruby >= 2.2
else
raise ArgumentError, "if provided, event_headers_style must be 'capitalized', 'downcased', 'snakecased' or 'raw'"
end
headers.each_with_object({}) { |(key, value), hash|
hash[normalize[key]] = value
}
end
def handle(data, payload = {})
url = interpolated(payload)[:post_url]
headers = headers()
case method
when 'get', 'delete'
params, body = data, nil
when 'post', 'put', 'patch'
params = nil
case (content_type = interpolated(payload)['content_type'])
when 'json'
headers['Content-Type'] = 'application/json; charset=utf-8'
body = data.to_json
when 'xml'
headers['Content-Type'] = 'text/xml; charset=utf-8'
body = data.to_xml(root: (interpolated(payload)[:xml_root] || 'post'))
when MIME_RE
headers['Content-Type'] = content_type
body = data.to_s
else
body = data
end
else
error "Invalid method '#{method}'"
end
response = faraday.run_request(method.to_sym, url, body, headers) { |request|
request.params.update(params) if params
}
if boolify(interpolated['emit_events'])
create_event payload: {
body: response.body,
headers: normalize_response_headers(response.headers),
status: response.status
}
end
end
end
end