Update Records from Plum automatically.

This subscribes to Plum's RabbitMQ exchange and uses the events there to
keep Pomegranate up to date with Plum.

Gemfile

@@ -77,3 +77,4 @@ gem 'social-share-button'
 gem 'devise_invitable'
 gem 'iiif-presentation'
 gem 'omniauth-cas'
+gem 'sneakers'

Gemfile.lock

@@ -76,6 +76,7 @@ GEM
     acts-as-taggable-on (3.5.0)
       activerecord (>= 3.2, < 5)
     addressable (2.4.0)
+    amq-protocol (2.0.1)
     arel (6.0.3)
     ast (2.2.0)
     astrolabe (1.3.1)
@@ -113,6 +114,8 @@ GEM
     bootstrap_form (2.3.0)
     breadcrumbs_on_rails (2.3.1)
     builder (3.2.2)
+    bunny (2.2.2)
+      amq-protocol (>= 2.0.1)
     byebug (8.2.1)
     cancancan (1.13.1)
     capistrano (3.4.0)
@@ -410,6 +413,9 @@ GEM
     sdoc (0.4.1)
       json (~> 1.7, >= 1.7.7)
       rdoc (~> 4.0)
+    serverengine (1.5.11)
+      sigdump (~> 0.2.2)
+    sigdump (0.2.3)
     signet (0.7.2)
       addressable (~> 2.3)
       faraday (~> 0.9)
@@ -427,6 +433,11 @@ GEM
     sitemap_generator (5.1.0)
       builder
     slop (3.6.0)
+    sneakers (2.3.5)
+      bunny (~> 2.2.0)
+      serverengine (~> 1.5.11)
+      thor
+      thread (~> 0.1.7)
     social-share-button (0.1.10)
       coffee-rails
       sass-rails
@@ -448,6 +459,7 @@ GEM
       diffy (~> 3.0)
       nokogiri (>= 1.3.2)
     thor (0.19.1)
+    thread (0.1.7)
     thread_safe (0.3.5)
     tilt (2.0.2)
     tins (1.6.0)
@@ -522,6 +534,7 @@ DEPENDENCIES
   sdoc (~> 0.4.0)
   simplecov (~> 0.9)
   sitemap_generator
+  sneakers
   social-share-button
   spring
   sqlite3

README.md

@@ -25,3 +25,14 @@ rake spotlight:exhibit
 ```
 
 After setup, run Pomegranate locally with `rails s`.
+
+### Auto-update from [Plum](https://github.com/pulibrary/plum)
+
+Plum announces events to a durable RabbitMQ fanout exchange. In order to use them, do the
+following:
+
+1. Configure the `events` settings in `config/config.yml`
+2. Run `WORKERS=PlumEventHandler rake sneakers:run`
+
+This will subscribe to the plum events and update the pomegranate records when they're
+created, updated, or deleted.

Rakefile

@@ -3,6 +3,7 @@
 
 require File.expand_path('../config/application', __FILE__)
 require 'rubocop/rake_task'
+require 'sneakers/tasks'
 
 Rails.application.load_tasks
 

app/services/plum_event_processor.rb

@@ -0,0 +1,27 @@
+class PlumEventProcessor
+  attr_reader :event
+  def initialize(event)
+    @event = event
+  end
+
+  delegate :process, to: :processor
+
+  private
+
+    def event_type
+      event["event"]
+    end
+
+    def processor
+      case event_type
+      when "CREATED"
+        CreateProcessor.new(event)
+      when "UPDATED"
+        UpdateProcessor.new(event)
+      when "DELETED"
+        DeleteProcessor.new(event)
+      else
+        NullProcessor
+      end
+    end
+end

app/services/plum_event_processor/create_processor.rb

@@ -0,0 +1,10 @@
+class PlumEventProcessor
+  class CreateProcessor < Processor
+    def process
+      exhibits.map do |exhibit|
+        resource = IIIFResource.new(manifest_url: manifest_url, exhibit: exhibit)
+        resource.save_and_index
+      end.all?(&:present?)
+    end
+  end
+end

app/services/plum_event_processor/delete_processor.rb

@@ -0,0 +1,12 @@
+class PlumEventProcessor
+  class DeleteProcessor < Processor
+    def process
+      IIIFResource.where(url: manifest_url).each do |resource|
+        index.delete_by_id resource.id.to_s
+        index.commit
+        resource.destroy
+      end
+      true
+    end
+  end
+end

app/services/plum_event_processor/null_processor.rb

@@ -0,0 +1,7 @@
+class PlumEventProcessor
+  class NullProcessor
+    def self.process
+      false
+    end
+  end
+end

app/services/plum_event_processor/processor.rb

@@ -0,0 +1,26 @@
+class PlumEventProcessor
+  class Processor
+    attr_reader :event
+    def initialize(event)
+      @event = event
+    end
+
+    private
+
+      def exhibits
+        Spotlight::Exhibit.where("slug IN (?)", collection_slugs)
+      end
+
+      def manifest_url
+        event["manifest_url"]
+      end
+
+      def collection_slugs
+        event["collection_slugs"]
+      end
+
+      def index
+        Blacklight.default_index.connection
+      end
+  end
+end

app/services/plum_event_processor/update_processor.rb

@@ -0,0 +1,54 @@
+class PlumEventProcessor
+  class UpdateProcessor < Processor
+    def process
+      delete_old_resources
+      update_existing_resources
+      create_new_resources
+      true
+    end
+
+    def delete_old_resources
+      delete_resources.each do |resource|
+        index.delete_by_id resource.id.to_s
+        index.commit
+        resource.destroy
+      end
+    end
+
+    def update_existing_resources
+      IIIFResource.where(url: manifest_url).each(&:save_and_index)
+    end
+
+    def create_new_resources
+      new_exhibits.each do |exhibit|
+        IIIFResource.new(manifest_url: manifest_url, exhibit: exhibit).save_and_index
+      end
+    end
+
+    private
+
+      def new_exhibits
+        Spotlight::Exhibit.where("slug IN (?)", new_exhibit_slugs)
+      end
+
+      def new_exhibit_slugs
+        collection_slugs - existing_slugs
+      end
+
+      def delete_resources
+        IIIFResource.where(url: manifest_url).joins(:exhibit).where('spotlight_exhibits.slug IN (?)', delete_slugs)
+      end
+
+      def delete_slugs
+        existing_slugs - collection_slugs
+      end
+
+      def existing_slugs
+        existing_resources.map(&:exhibit).map(&:slug)
+      end
+
+      def existing_resources
+        IIIFResource.where(url: manifest_url)
+      end
+  end
+end

app/workers/plum_event_handler.rb

@@ -0,0 +1,14 @@
+class PlumEventHandler
+  include Sneakers::Worker
+  from_queue :pomegranate
+
+  def work(msg)
+    msg = JSON.parse(msg)
+    result = PlumEventProcessor.new(msg).process
+    if result
+      ack!
+    else
+      reject!
+    end
+  end
+end

bin/jetty_wait

@@ -1,6 +1,6 @@
 #!/usr/bin/env sh
 
-until $(curl --output /dev/null --silent --head --fail http://localhost:8983/solr); do
+until $(curl --output /dev/null --silent --head --fail http://localhost:8980/solr); do
     printf '.'
     sleep 1
 done

circle.yml

@@ -13,7 +13,7 @@ dependencies:
     - sudo sh bin/ci_kakadu_install.sh
     - RAILS_ENV=development bundle exec rake jetty:unzip
     - bundle exec rake jetty:configure_solr
-    - cd jetty && java -Djetty.port=8983 -Dsolr.solr.home=/home/ubuntu/pomegranate/jetty/solr -XX:MaxPermSize=256m -Xmx512m -jar start.jar:
+    - cd jetty && java -Djetty.port=8980 -Dsolr.solr.home=/home/ubuntu/pomegranate/jetty/solr -XX:MaxPermSize=256m -Xmx512m -jar start.jar:
         background: true
     - bin/jetty_wait
 test:

config/application.rb

@@ -25,5 +25,6 @@ class Application < Rails::Application
 
     # Do not swallow errors in after_commit/after_rollback callbacks.
     config.active_record.raise_in_transactional_callbacks = true
+    config.autoload_paths += %W(#{Rails.root}/app/workers)
   end
 end

config/blacklight.yml

@@ -12,12 +12,12 @@
 
 development:
   adapter: solr
-  url: <%= ENV['SOLR_URL'] || "http://127.0.0.1:8983/solr/blacklight-core" %>
+  url: <%= ENV['SOLR_URL'] || "http://127.0.0.1:8980/solr/blacklight-core" %>
 test: &test
   adapter: solr
-  url: <%= "http://127.0.0.1:#{ENV['TEST_JETTY_PORT'] || 8983}/solr/blacklight-test" %>
+  url: <%= "http://127.0.0.1:#{ENV['TEST_JETTY_PORT'] || 8980}/solr/blacklight-test" %>
 production: &production
   adapter: solr
-  url: <%= ENV['POMEGRANATE_SOLR_URL'] || "http://127.0.0.1:8983/solr/blacklight-core" %>
+  url: <%= ENV['POMEGRANATE_SOLR_URL'] || "http://127.0.0.1:8980/solr/blacklight-core" %>
 staging: 
   <<: *production

config/config.yml

@@ -1,8 +1,12 @@
 defaults: &defaults
   all_collection_manifest_url: "https://hydra-dev.princeton.edu/collections/manifest"
+  events:
+    server: 'amqp://localhost:5672'
+    exchange: 'plum_events'
 
 development:
   <<: *defaults
+  all_collection_manifest_url: "http://localhost:3000/collections/manifest"
 
 test:
   <<: *defaults

config/initializers/sneakers.rb

@@ -0,0 +1,7 @@
+require 'sneakers'
+require_relative 'pom_config'
+Sneakers.configure(
+  amqp: Pomegranate.config["events"]["server"],
+  exchange: Pomegranate.config["events"]["exchange"],
+  exchange_type: :fanout
+)

config/jetty.yml

@@ -1,10 +1,10 @@
 development:
   startup_wait: 15
-  jetty_port: 8983
+  jetty_port: 8980
   java_version: ">= 1.7"
 test:
   startup_wait: 60
-  jetty_port: <%= ENV['TEST_JETTY_PORT'] || 8888 %>
+  jetty_port: <%= ENV['TEST_JETTY_PORT'] || 8980 %>
   <%= ENV['TEST_JETTY_PATH'] ? "jetty_home: " + ENV['TEST_JETTY_PATH'] : '' %>
   java_version: ">= 1.7"
 production: