WEB-3340: Adding native slack notifications if the required URL provided

.env.sample

@@ -14,3 +14,6 @@ AWS_REGION=
 
 # CDN for image uploads
 IMAGES_CDN_HOST=
+
+# Build notifications as part of CI
+SLACK_WEBHOOK_URL=

app/lib/renderer/image_attributes.rb

@@ -35,6 +35,7 @@ def width_class(alt_text)
       width_match = /width=(\d+)%/.match(alt_text)
       return if width_match.blank?
 
+      # Convert width request to a class that's a multiple of 10
       width = width_match[1].to_i.round(-1).clamp(0, 100)
       "l-image-#{width}"
     end

app/lib/runner/base.rb

@@ -4,6 +4,7 @@ module Runner
   # Base class with shared functionality
   class Base
     include Util::Logging
+    include Util::SlackNotifiable
 
     def self.runner
       return Runner::Ci.new if CI
@@ -23,16 +24,18 @@ def render(publish_file:, local: false)
       book
     end
 
-    def publish(publish_file:)
+    def publish(publish_file:) # rubocop:disable Metrics/MethodLength
       publish_file ||= default_publish_file
-
       parser = Parser::Publish.new(file: publish_file)
       book = parser.parse
       image_provider = ImageProvider::Provider.new(book: book)
       image_provider.process
-      renderer = Renderer::Book.new(book: book, image_provider: image_provider)
-      renderer.render
+      Renderer::Book.new(book: book, image_provider: image_provider).render
       Api::Alexandria::BookUploader.upload(book)
+      notify_success(book: book)
+    rescue StandardError => e
+      notify_failure(book: defined?(book) ? book : nil, details: e.full_message)
+      raise e
     end
 
     def lint(publish_file:, options: {})

app/lib/util/slack_notifiable.rb

@@ -0,0 +1,119 @@
+# frozen_string_literal: true
+
+module Util
+  # Adds methods that allow slack notifications
+  module SlackNotifiable # rubocop:disable Metrics/ModuleLength
+    extend ActiveSupport::Concern
+
+    SUCCESS_IMAGE_URL = 'https://wolverine.raywenderlich.com/v3-resources/razebot/images/object_textkit-book.png'
+    FAILURE_IMAGE_URL = 'https://wolverine.raywenderlich.com/v3-resources/razebot/images/object_errors.png'
+    ROBLES_CONTEXT_IMAGE_URL = 'https://wolverine.raywenderlich.com/v3-resources/razebot/images/object_box-of-books.png'
+
+    def notify_success(book:)
+      return unless notifiable?
+
+      notifier.post(blocks: success_blocks(book: book))
+    end
+
+    def notify_failure(book:, details: nil)
+      return unless notifiable?
+
+      notifier.post(blocks: failure_blocks(book: book, details: details || 'N/A'))
+    end
+
+    def notifiable?
+      SLACK_WEBHOOK_URL.present?
+    end
+
+    def notifier
+      @notifier ||= Slack::Notifier.new(SLACK_WEBHOOK_URL, channel: SLACK_CHANNEL, username: SLACK_USERNAME)
+    end
+
+    def success_blocks(book:)
+      [
+        intro_section(book: book,
+                      message: ':white_check_mark: Book publication successful!',
+                      image_url: SUCCESS_IMAGE_URL,
+                      alt_text: 'Publication successful'),
+        {
+          type: 'divider'
+        },
+        context
+      ]
+    end
+
+    def failure_blocks(book:, details:) # rubocop:disable Metrics/MethodLength
+      [
+        intro_section(book: book,
+                      message: ':x: Book publication failed!',
+                      image_url: FAILURE_IMAGE_URL,
+                      alt_text: 'Publication failed'),
+        {
+          type: 'section',
+          text: {
+            type: 'mrkdwn',
+            text: "```#{details}```"
+          }
+        },
+        {
+          type: 'divider'
+        },
+        context
+      ]
+    end
+
+    def standard_fields(book:) # rubocop:disable Metrics/MethodLength
+      [
+        {
+          type: 'mrkdwn',
+          text: "*Book*\n#{book&.title || '_unknown_'}"
+        },
+        {
+          type: 'mrkdwn',
+          text: "*SKU*\n`#{book&.sku || 'unknown'}`"
+        },
+        {
+          type: 'mrkdwn',
+          text: "*Edition*\n#{book&.edition || '_unknown_'}"
+        },
+        {
+          type: 'mrkdwn',
+          text: "*Environment*\n`#{ENVIRONMENT}`"
+        }
+      ]
+    end
+
+    def intro_section(book:, message:, image_url:, alt_text:) # rubocop:disable Metrics/MethodLength
+      {
+        type: 'section',
+        text: {
+          type: 'mrkdwn',
+          text: message
+        },
+        fields: standard_fields(book: book),
+        accessory: {
+          type: 'image',
+          image_url: image_url,
+          alt_text: alt_text
+        }
+      }
+    end
+
+    def context # rubocop:disable Metrics/MethodLength
+      {
+        type: 'context',
+        elements: [
+          {
+            type: 'image',
+            image_url: ROBLES_CONTEXT_IMAGE_URL,
+            alt_text: 'robles via razebot'
+          },
+          {
+            type: 'mrkdwn',
+            text: 'This is a message sent from *robles* via *razebot*.'
+          }
+        ]
+      }
+    end
+  end
+end

config/initialisers/environment.rb

@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+ENVIRONMENT = ENV['ENV'] || 'development'

config/initialisers/slack.rb

@@ -1,3 +1,5 @@
 # frozen_string_literal: true
 
 SLACK_WEBHOOK_URL = ENV['SLACK_WEBHOOK_URL']
+SLACK_CHANNEL = ENV['SLACK_CHANNEL'] || '#robles'
+SLACK_USERNAME = ENV['SLACK_USERNAME'] || 'razebot'