Implement PagerDuty webhook payload parser

lib/pager_duty/webhook_payload_parser.rb

+# frozen_string_literal: true
+
+module PagerDuty
+  class WebhookPayloadParser
+    def initialize(payload)
+      @payload = payload
+    end
+
+    def self.call(payload)
+      new(payload).call
+    end
+
+    def call
+      Array(payload['messages']).map { |msg| parse_message(msg) }
+    end
+
+    private
+
+    attr_reader :payload
+
+    def parse_message(message)
+      {
+        'event' => message['event'],
+        'incident' => parse_incident(message['incident'])
+      }
+    end
+
+    def parse_incident(incident)
+      return {} if incident.blank?
+
+      {
+        'url' => incident['html_url'],
+        'incident_number' => incident['incident_number'],
+        'title' => incident['title'],
+        'status' => incident['status'],
+        'created_at' => incident['created_at'],
+        'urgency' => incident['urgency'],
+        'incident_key' => incident['incident_key'],
+        'assignees' => reject_empty(parse_assignees(incident)),
+        'impacted_services' => reject_empty(parse_impacted_services(incident))
+      }
+    end
+
+    def parse_assignees(incident)
+      Array(incident['assignments']).map do |a|
+        {
+          'summary' => a.dig('assignee', 'summary'),
+          'url' => a.dig('assignee', 'html_url')
+        }
+      end
+    end
+
+    def parse_impacted_services(incident)
+      Array(incident['impacted_services']).map do |is|
+        {
+          'summary' => is['summary'],
+          'url' => is['html_url']
+        }
+      end
+    end
+
+    def reject_empty(entities)
+      Array(entities).reject { |e| e['summary'].blank? && e['url'].blank? }
+    end
+  end
+end

spec/fixtures/pager_duty/webhook_incident_trigger.json

+{
+  "messages": [
+    {
+      "event": "incident.trigger",
+      "log_entries": [
+        {
+          "id": "R2XGXEI3W0FHMSDXHDIBQGBQ5E",
+          "type": "trigger_log_entry",
+          "summary": "Triggered through the website",
+          "self": "https://api.pagerduty.com/log_entries/R2XGXEI3W0FHMSDXHDIBQGBQ5E",
+          "html_url": "https://webdemo.pagerduty.com/incidents/PRORDTY/log_entries/R2XGXEI3W0FHMSDXHDIBQGBQ5E",
+          "created_at": "2017-09-26T15:14:36Z",
+          "agent": {
+            "id": "P553OPV",
+            "type": "user_reference",
+            "summary": "Laura Haley",
+            "self": "https://api.pagerduty.com/users/P553OPV",
+            "html_url": "https://webdemo.pagerduty.com/users/P553OPV"
+          },
+          "channel": {
+            "type": "web_trigger",
+            "summary": "My new incident",
+            "subject": "My new incident",
+            "details": "Oh my gosh",
+            "details_omitted": false
+          },
+          "service": {
+            "id": "PN49J75",
+            "type": "service_reference",
+            "summary": "Production XDB Cluster",
+            "self": "https://api.pagerduty.com/services/PN49J75",
+            "html_url": "https://webdemo.pagerduty.com/services/PN49J75"
+          },
+          "incident": {
+            "id": "PRORDTY",
+            "type": "incident_reference",
+            "summary": "[#33] My new incident",
+            "self": "https://api.pagerduty.com/incidents/PRORDTY",
+            "html_url": "https://webdemo.pagerduty.com/incidents/PRORDTY"
+          },
+          "teams": [
+            {
+              "id": "P4SI59S",
+              "type": "team_reference",
+              "summary": "Engineering",
+              "self": "https://api.pagerduty.com/teams/P4SI59S",
+              "html_url": "https://webdemo.pagerduty.com/teams/P4SI59S"
+            }
+          ],
+          "contexts": [],
+          "event_details": {
+            "description": "My new incident"
+          }
+        }
+      ],
+      "webhook": {
+        "endpoint_url": "https://requestb.in/18ao6fs1",
+        "name": "V2 wabhook",
+        "description": null,
+        "webhook_object": {
+          "id": "PN49J75",
+          "type": "service_reference",
+          "summary": "Production XDB Cluster",
+          "self": "https://api.pagerduty.com/services/PN49J75",
+          "html_url": "https://webdemo.pagerduty.com/services/PN49J75"
+        },
+        "config": {},
+        "outbound_integration": {
+          "id": "PJFWPEP",
+          "type": "outbound_integration_reference",
+          "summary": "Generic V2 Webhook",
+          "self": "https://api.pagerduty.com/outbound_integrations/PJFWPEP",
+          "html_url": null
+        },
+        "accounts_addon": null,
+        "id": "PKT9NNX",
+        "type": "webhook",
+        "summary": "V2 wabhook",
+        "self": "https://api.pagerduty.com/webhooks/PKT9NNX",
+        "html_url": null
+      },
+      "incident": {
+        "incident_number": 33,
+        "title": "My new incident",
+        "description": "My new incident",
+        "created_at": "2017-09-26T15:14:36Z",
+        "status": "triggered",
+        "pending_actions": [
+          {
+            "type": "escalate",
+            "at": "2017-09-26T15:44:36Z"
+          },
+          {
+            "type": "resolve",
+            "at": "2017-09-26T19:14:36Z"
+          }
+        ],
+        "incident_key": null,
+        "service": {
+          "id": "PN49J75",
+          "name": "Production XDB Cluster",
+          "description": "This service was created during onboarding on July 5, 2017.",
+          "auto_resolve_timeout": 14400,
+          "acknowledgement_timeout": 1800,
+          "created_at": "2017-07-05T17:33:09Z",
+          "status": "critical",
+          "last_incident_timestamp": "2017-09-26T15:14:36Z",
+          "teams": [
+            {
+              "id": "P4SI59S",
+              "type": "team_reference",
+              "summary": "Engineering",
+              "self": "https://api.pagerduty.com/teams/P4SI59S",
+              "html_url": "https://webdemo.pagerduty.com/teams/P4SI59S"
+            }
+          ],
+          "incident_urgency_rule": {
+            "type": "constant",
+            "urgency": "high"
+          },
+          "scheduled_actions": [],
+          "support_hours": null,
+          "escalation_policy": {
+            "id": "PINYWEF",
+            "type": "escalation_policy_reference",
+            "summary": "Default",
+            "self": "https://api.pagerduty.com/escalation_policies/PINYWEF",
+            "html_url": "https://webdemo.pagerduty.com/escalation_policies/PINYWEF"
+          },
+          "addons": [],
+          "privilege": null,
+          "alert_creation": "create_alerts_and_incidents",
+          "integrations": [
+            {
+              "id": "PUAYF96",
+              "type": "generic_events_api_inbound_integration_reference",
+              "summary": "API",
+              "self": "https://api.pagerduty.com/services/PN49J75/integrations/PUAYF96",
+              "html_url": "https://webdemo.pagerduty.com/services/PN49J75/integrations/PUAYF96"
+            },
+            {
+              "id": "P90GZUH",
+              "type": "generic_email_inbound_integration_reference",
+              "summary": "Email",
+              "self": "https://api.pagerduty.com/services/PN49J75/integrations/P90GZUH",
+              "html_url": "https://webdemo.pagerduty.com/services/PN49J75/integrations/P90GZUH"
+            }
+          ],
+          "metadata": {},
+          "type": "service",
+          "summary": "Production XDB Cluster",
+          "self": "https://api.pagerduty.com/services/PN49J75",
+          "html_url": "https://webdemo.pagerduty.com/services/PN49J75"
+        },
+        "assignments": [
+          {
+            "at": "2017-09-26T15:14:36Z",
+            "assignee": {
+              "id": "P553OPV",
+              "type": "user_reference",
+              "summary": "Laura Haley",
+              "self": "https://api.pagerduty.com/users/P553OPV",
+              "html_url": "https://webdemo.pagerduty.com/users/P553OPV"
+            }
+          }
+        ],
+        "acknowledgements": [],
+        "last_status_change_at": "2017-09-26T15:14:36Z",
+        "last_status_change_by": {
+          "id": "PN49J75",
+          "type": "service_reference",
+          "summary": "Production XDB Cluster",
+          "self": "https://api.pagerduty.com/services/PN49J75",
+          "html_url": "https://webdemo.pagerduty.com/services/PN49J75"
+        },
+        "first_trigger_log_entry": {
+          "id": "R2XGXEI3W0FHMSDXHDIBQGBQ5E",
+          "type": "trigger_log_entry_reference",
+          "summary": "Triggered through the website",
+          "self": "https://api.pagerduty.com/log_entries/R2XGXEI3W0FHMSDXHDIBQGBQ5E",
+          "html_url": "https://webdemo.pagerduty.com/incidents/PRORDTY/log_entries/R2XGXEI3W0FHMSDXHDIBQGBQ5E"
+        },
+        "escalation_policy": {
+          "id": "PINYWEF",
+          "type": "escalation_policy_reference",
+          "summary": "Default",
+          "self": "https://api.pagerduty.com/escalation_policies/PINYWEF",
+          "html_url": "https://webdemo.pagerduty.com/escalation_policies/PINYWEF"
+        },
+        "privilege": null,
+        "teams": [
+          {
+            "id": "P4SI59S",
+            "type": "team_reference",
+            "summary": "Engineering",
+            "self": "https://api.pagerduty.com/teams/P4SI59S",
+            "html_url": "https://webdemo.pagerduty.com/teams/P4SI59S"
+          }
+        ],
+        "alert_counts": {
+          "all": 0,
+          "triggered": 0,
+          "resolved": 0
+        },
+        "impacted_services": [
+          {
+            "id": "PN49J75",
+            "type": "service_reference",
+            "summary": "Production XDB Cluster",
+            "self": "https://api.pagerduty.com/services/PN49J75",
+            "html_url": "https://webdemo.pagerduty.com/services/PN49J75"
+          }
+        ],
+        "is_mergeable": true,
+        "basic_alert_grouping": null,
+        "alert_grouping": null,
+        "metadata": {},
+        "external_references": [],
+        "importance": null,
+        "incidents_responders": [],
+        "responder_requests": [],
+        "subscriber_requests": [],
+        "urgency": "high",
+        "id": "PRORDTY",
+        "type": "incident",
+        "summary": "[#33] My new incident",
+        "self": "https://api.pagerduty.com/incidents/PRORDTY",
+        "html_url": "https://webdemo.pagerduty.com/incidents/PRORDTY",
+        "alerts": [
+          {
+            "alert_key": "c24117fc42e44b44b4d6876190583378"
+          }
+        ]
+      },
+      "id": "69a7ced0-a2cd-11e7-a799-22000a15839c",
+      "created_on": "2017-09-26T15:14:36Z"
+    }
+  ]
+}

spec/lib/pager_duty/webhook_payload_parser_spec.rb

+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+
+RSpec.describe PagerDuty::WebhookPayloadParser do
+  describe '.call' do
+    let(:fixture_file) do
+      File.read(File.join(File.dirname(__FILE__), '../../fixtures/pager_duty/webhook_incident_trigger.json'))
+    end
+
+    subject(:parse) { described_class.call(payload) }
+
+    context 'when payload is a correct PagerDuty payload' do
+      let(:payload) { Gitlab::Json.parse(fixture_file) }
+
+      it 'returns parsed payload' do
+        is_expected.to eq(
+          [
+            {
+              'event' => 'incident.trigger',
+              'incident' => {
+                'url' => 'https://webdemo.pagerduty.com/incidents/PRORDTY',
+                'incident_number' => 33,
+                'title' => 'My new incident',
+                'status' => 'triggered',
+                'created_at' => '2017-09-26T15:14:36Z',
+                'urgency' => 'high',
+                'incident_key' => nil,
+                'assignees' => [{
+                  'summary' => 'Laura Haley',
+                  'url' => 'https://webdemo.pagerduty.com/users/P553OPV'
+                }],
+                'impacted_services' => [{
+                  'summary' => 'Production XDB Cluster',
+                  'url' => 'https://webdemo.pagerduty.com/services/PN49J75'
+                }]
+              }
+            }
+          ]
+        )
+      end
+
+      context 'when assignments summary and html_url are blank' do
+        before do
+          payload['messages'].each do |m|
+            m['incident']['assignments'] = [{ 'assignee' => { 'summary' => '', 'html_url' => '' } }]
+          end
+        end
+
+        it 'returns parsed payload with blank assignees' do
+          assignees = parse.map { |events| events['incident'].slice('assignees') }
+
+          expect(assignees).to eq([{ 'assignees' => [] }])
+        end
+      end
+
+      context 'when impacted_services summary and html_url are blank' do
+        before do
+          payload['messages'].each do |m|
+            m['incident']['impacted_services'] = [{ 'summary' => '', 'html_url' => '' }]
+          end
+        end
+
+        it 'returns parsed payload with blank assignees' do
+          assignees = parse.map { |events| events['incident'].slice('impacted_services') }
+
+          expect(assignees).to eq([{ 'impacted_services' => [] }])
+        end
+      end
+    end
+
+    context 'when payload has no incidents' do
+      let(:payload) { { 'messages' => [{ 'event' => 'incident.trigger' }] } }
+
+      it 'returns payload with blank incidents' do
+        is_expected.to eq([{ 'event' => 'incident.trigger', 'incident' => {} }])
+      end
+    end
+  end
+end