post_agent.rb 7.6KB

    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| interpolate_with(event) do outgoing = interpolated['payload'].presence || {} if boolify(interpolated['no_merge']) handle outgoing, event.payload, headers(interpolated[:headers]) else handle outgoing.merge(event.payload), event.payload, headers(interpolated[:headers]) end end end end def check handle interpolated['payload'].presence || {}, headers 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 = {}, headers) url = interpolated(payload)[:post_url] 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