From 392518a18b8ea746c87fb500b20f46d9d1dca201 Mon Sep 17 00:00:00 2001
From: Mathis-Z <Mathis.Zscheischler@gmail.com>
Date: Tue, 25 Jun 2024 20:30:44 +0200
Subject: [PATCH] Adding NBP push connector

---
 Gemfile                                       |   1 +
 Gemfile.lock                                  |  13 ++
 app/jobs/application_job.rb                   |   5 +
 app/jobs/concerns/active_record_logging.rb    |  20 +++
 app/jobs/nbp_delete_job.rb                    |  11 ++
 app/jobs/nbp_push_all_job.rb                  |   9 ++
 app/jobs/nbp_push_job.rb                      |  13 ++
 app/models/task.rb                            |  21 +++-
 config/application.rb                         |   3 +
 config/environments/development.rb            |   4 +
 config/environments/production.rb             |   4 +-
 config/environments/test.rb                   |   4 +
 config/schedule.rb                            |   1 +
 config/settings/test.yml                      |  11 ++
 config/solid_queue.yml                        |  18 +++
 config/solid_queue_defaults.rb                |  39 ++++++
 ...9_create_solid_queue_tables.solid_queue.rb | 103 ++++++++++++++++
 ...index_to_blocked_executions.solid_queue.rb |   8 ++
 ...create_recurring_executions.solid_queue.rb |  17 +++
 db/schema.rb                                  | 111 ++++++++++++++++-
 docs/LOCAL_SETUP.md                           |  13 +-
 lib/nbp/push_connector.rb                     | 114 ++++++++++++++++++
 lib/tasks/nbp_push_all_tasks.rake             |   8 ++
 spec/lib/nbp/push_connector_spec.rb           |  47 ++++++++
 spec/models/task_spec.rb                      |  48 ++++++++
 25 files changed, 641 insertions(+), 5 deletions(-)
 create mode 100644 app/jobs/application_job.rb
 create mode 100644 app/jobs/concerns/active_record_logging.rb
 create mode 100644 app/jobs/nbp_delete_job.rb
 create mode 100644 app/jobs/nbp_push_all_job.rb
 create mode 100644 app/jobs/nbp_push_job.rb
 create mode 100644 config/solid_queue.yml
 create mode 100644 config/solid_queue_defaults.rb
 create mode 100644 db/migrate/20240609104039_create_solid_queue_tables.solid_queue.rb
 create mode 100644 db/migrate/20240609104040_add_missing_index_to_blocked_executions.solid_queue.rb
 create mode 100644 db/migrate/20240609104041_create_recurring_executions.solid_queue.rb
 create mode 100644 lib/nbp/push_connector.rb
 create mode 100644 lib/tasks/nbp_push_all_tasks.rake
 create mode 100644 spec/lib/nbp/push_connector_spec.rb

diff --git a/Gemfile b/Gemfile
index 56c42e027..eac3f8645 100644
--- a/Gemfile
+++ b/Gemfile
@@ -36,6 +36,7 @@ gem 'sassc-rails'
 gem 'shakapacker', '8.0.0'
 gem 'simple_form'
 gem 'slim-rails'
+gem 'solid_queue'
 gem 'sprockets-rails'
 gem 'terser'
 gem 'turbolinks'
diff --git a/Gemfile.lock b/Gemfile.lock
index c4cbc75b1..5c8b0c731 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -153,6 +153,8 @@ GEM
     docile (1.4.0)
     drb (2.2.1)
     erubi (1.13.0)
+    et-orbi (1.2.11)
+      tzinfo
     execjs (2.9.1)
     factory_bot (6.4.6)
       activesupport (>= 5.0.0)
@@ -164,6 +166,9 @@ GEM
     faraday-net_http (3.1.0)
       net-http
     ffi (1.17.0)
+    fugit (1.11.0)
+      et-orbi (~> 1, >= 1.2.11)
+      raabro (~> 1.4)
     glob (0.4.1)
     globalid (1.2.1)
       activesupport (>= 6.1)
@@ -314,6 +319,7 @@ GEM
       rspec-expectations (~> 3.12)
       rspec-mocks (~> 3.12)
       rspec-support (~> 3.12)
+    raabro (1.4.0)
     racc (1.8.0)
     rack (3.1.3)
     rack-mini-profiler (3.3.1)
@@ -500,6 +506,12 @@ GEM
     slim_lint (0.27.0)
       rubocop (>= 1.0, < 2.0)
       slim (>= 3.0, < 6.0)
+    solid_queue (0.3.3)
+      activejob (>= 7.1)
+      activerecord (>= 7.1)
+      concurrent-ruby (>= 1.3.1)
+      fugit (~> 1.11.0)
+      railties (>= 7.1)
     sorted_set (1.0.3)
       rbtree
       set (~> 1.0)
@@ -629,6 +641,7 @@ DEPENDENCIES
   simplecov
   slim-rails
   slim_lint
+  solid_queue
   sprockets-rails
   stackprof
   terser
diff --git a/app/jobs/application_job.rb b/app/jobs/application_job.rb
new file mode 100644
index 000000000..27cfbfd7a
--- /dev/null
+++ b/app/jobs/application_job.rb
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+class ApplicationJob < ActiveJob::Base
+  include ActiveRecordLogging
+end
diff --git a/app/jobs/concerns/active_record_logging.rb b/app/jobs/concerns/active_record_logging.rb
new file mode 100644
index 000000000..5a2c38c4a
--- /dev/null
+++ b/app/jobs/concerns/active_record_logging.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+# This module is used to log ActiveRecord queries performed in jobs.
+module ActiveRecordLogging
+  extend ActiveSupport::Concern
+
+  included do
+    around_perform do |_job, block|
+      # With our current Solid Queue setup, there is a difference between both logger:
+      # - *ActiveRecord::Base.logger*: This logger is used for SQL queries and, normally, writes to the log file only.
+      # - *Rails.logger*: The regular logger, which writes to the log file and the console.
+      # For the duration of the job, we want to write the SQL queries to the Rails logger, so they show up in the console.
+      # See config/solid_queue_logging.rb for more information.
+      previous_logger = ActiveRecord::Base.logger
+      ActiveRecord::Base.logger = Rails.logger
+      block.call
+      ActiveRecord::Base.logger = previous_logger
+    end
+  end
+end
diff --git a/app/jobs/nbp_delete_job.rb b/app/jobs/nbp_delete_job.rb
new file mode 100644
index 000000000..b4ace0d3c
--- /dev/null
+++ b/app/jobs/nbp_delete_job.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class NbpDeleteJob < ApplicationJob
+  retry_on Faraday::Error, wait: :polynomially_longer
+
+  def perform(task_uuid)
+    Nbp::PushConnector.instance.delete_task!(task_uuid)
+
+    Rails.logger.debug { "Task with UUID #{task_uuid} deleted from NBP" }
+  end
+end
diff --git a/app/jobs/nbp_push_all_job.rb b/app/jobs/nbp_push_all_job.rb
new file mode 100644
index 000000000..56ac90184
--- /dev/null
+++ b/app/jobs/nbp_push_all_job.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class NbpPushAllJob < ApplicationJob
+  def perform
+    Task.find_each(batch_size: 50) do |task|
+      NbpPushJob.perform_later task
+    end
+  end
+end
diff --git a/app/jobs/nbp_push_job.rb b/app/jobs/nbp_push_job.rb
new file mode 100644
index 000000000..c56ff7e3a
--- /dev/null
+++ b/app/jobs/nbp_push_job.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class NbpPushJob < ApplicationJob
+  retry_on Faraday::Error, wait: :polynomially_longer, attempts: 5
+
+  def perform(task)
+    builder = Nokogiri::XML::Builder.new(encoding: 'UTF-8') {|xml| LomService::ExportLom.call(task:, xml:) }
+
+    Nbp::PushConnector.instance.push_lom!(builder.to_xml)
+
+    Rails.logger.debug { "Task ##{task.id} \"#{task}\" pushed to NBP" }
+  end
+end
diff --git a/app/models/task.rb b/app/models/task.rb
index 0872dfc74..2b1292ff5 100644
--- a/app/models/task.rb
+++ b/app/models/task.rb
@@ -5,11 +5,14 @@
 class Task < ApplicationRecord
   acts_as_taggable_on :state
 
+  before_validation :lowercase_language
+  after_destroy_commit :remove_metadata_from_nbp, if: -> { Nbp::PushConnector.enabled? }
+  after_save_commit :sync_metadata_with_nbp, if: -> { Nbp::PushConnector.enabled? }
+
   validates :title, presence: true
 
   validates :uuid, uniqueness: true
 
-  before_validation :lowercase_language
   validates :language, format: {with: /\A[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*\z/, message: :not_de_or_us}
   validate :primary_language_tag_in_iso639?
 
@@ -102,6 +105,22 @@ def self.ransackable_associations(_auth_object = nil)
     %w[labels]
   end
 
+  def sync_metadata_with_nbp
+    if access_level_public?
+      publish_metadata_to_nbp
+    elsif saved_change_to_access_level?
+      remove_metadata_from_nbp
+    end
+  end
+
+  def publish_metadata_to_nbp
+    NbpPushJob.perform_later self
+  end
+
+  def remove_metadata_from_nbp
+    NbpDeleteJob.perform_later uuid
+  end
+
   # This method creates a duplicate while leaving permissions and ownership unchanged
   def duplicate
     dup.tap do |task|
diff --git a/config/application.rb b/config/application.rb
index 4a01363fb..bcbeffd74 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -50,5 +50,8 @@ class Application < Rails::Application
 
     # Fix invalid Content-Type header for incoming requests made by edu-sharing.
     config.middleware.insert_before 0, Middleware::EduSharingContentType
+
+    # Configure some defaults for the Solid Queue Supervisor
+    require_relative 'solid_queue_defaults'
   end
 end
diff --git a/config/environments/development.rb b/config/environments/development.rb
index 80d25f19b..cda0c98b1 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -44,6 +44,10 @@
   # Don't care if the mailer can't send.
   config.action_mailer.raise_delivery_errors = false
 
+  # Use a real queuing backend for Active Job (and separate queues per environment).
+  config.active_job.queue_adapter = :solid_queue
+  config.active_job.queue_name_prefix = 'codeharbor_development'
+
   config.action_mailer.perform_caching = false
 
   # Print deprecation notices to the Rails logger.
diff --git a/config/environments/production.rb b/config/environments/production.rb
index c167344d6..a5249631a 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -77,8 +77,8 @@
   # config.cache_store = :mem_cache_store
 
   # Use a real queuing backend for Active Job (and separate queues per environment).
-  # config.active_job.queue_adapter     = :resque
-  # config.active_job.queue_name_prefix = "codeharbor_production"
+  config.active_job.queue_adapter = :solid_queue
+  config.active_job.queue_name_prefix = 'codeharbor_production'
 
   config.action_mailer.perform_caching = false
 
diff --git a/config/environments/test.rb b/config/environments/test.rb
index 70f731662..79c2510d0 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -39,6 +39,10 @@
   # Store uploaded files on the local file system in a temporary directory.
   config.active_storage.service = :test
 
+  # Use a real queuing backend for Active Job (and separate queues per environment).
+  config.active_job.queue_adapter = :solid_queue
+  config.active_job.queue_name_prefix = 'codeharbor_test'
+
   config.action_mailer.perform_caching = false
 
   # Tell Action Mailer not to deliver emails to the real world.
diff --git a/config/schedule.rb b/config/schedule.rb
index 072c66669..9c8afb02d 100644
--- a/config/schedule.rb
+++ b/config/schedule.rb
@@ -28,4 +28,5 @@
 
 every 1.day, at: '3:00 am' do
   rake 'import_cache_files:cleanup'
+  runner 'SolidQueue::Job.clear_finished_in_batches'
 end
diff --git a/config/settings/test.yml b/config/settings/test.yml
index e58f8e258..ebdcd1cd8 100644
--- a/config/settings/test.yml
+++ b/config/settings/test.yml
@@ -13,3 +13,14 @@ omniauth:
     private_key: ~
 oai_pmh:
   admin_mail: admin@example.org
+nbp:
+  push_connector:
+    enable: true
+    client_id: testing_client_id
+    client_secret: testing_client_secret
+    token_path: 'https://test.provider/token'
+    api_host: 'https://test.api.host'
+    source:
+      organization: test_organization
+      name: CodeHarbor
+      slug: CoHaP2
diff --git a/config/solid_queue.yml b/config/solid_queue.yml
new file mode 100644
index 000000000..2d8d922f1
--- /dev/null
+++ b/config/solid_queue.yml
@@ -0,0 +1,18 @@
+# default: &default
+#   dispatchers:
+#     - polling_interval: 1
+#       batch_size: 500
+#   workers:
+#     - queues: "*"
+#       threads: 3
+#       processes: 1
+#       polling_interval: 0.1
+#
+# development:
+#  <<: *default
+#
+# test:
+#  <<: *default
+#
+# production:
+#  <<: *default
diff --git a/config/solid_queue_defaults.rb b/config/solid_queue_defaults.rb
new file mode 100644
index 000000000..d30aadd5f
--- /dev/null
+++ b/config/solid_queue_defaults.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+# This file must be loaded before other initializers due to the logging configuration.
+Rails.application.configure do
+  # On shutdown, jobs Solid Queue will wait the specified timeout before forcefully shutting down.
+  # Any job not finished by then will be picked up again after a restart.
+  config.solid_queue.shutdown_timeout = 10.seconds
+  # Remove *successful* jobs from the database after 30 days
+  config.solid_queue.clear_finished_jobs_after = 30.days
+  config.solid_queue.supervisor_pidfile = Rails.root.join('tmp/pids/solid_queue_supervisor.pid')
+
+  # For Solid Queue, we want to hide regular SQL queries from the console, but still log them to a separate file.
+  # For the normal webserver, this dedicated setup is neither needed nor desired.
+  next unless Rake.application.top_level_tasks.to_s.include?('solid_queue:')
+
+  # Specify that all logs should be written to the specified log file
+  file_name = "#{Rails.env}.solid_queue.log"
+  config.paths.add 'log', with: "log/#{file_name}"
+
+  # Send all logs regarding SQL queries to the log file.
+  # This will include all queries performed by Solid Queue including periodic job checks.
+  log_file = ActiveSupport::Logger.new(Rails.root.join('log', file_name))
+  config.active_record.logger = ActiveSupport::BroadcastLogger.new(log_file)
+
+  config.after_initialize do
+    # Create a new logger that will write to the console
+    console = ActiveSupport::Logger.new($stdout)
+    console.level = Rails.logger.level
+    # Enable this line to have the same log format as Rails.logger
+    # It will include the job name, the job ID for each line
+    # console.formatter = Rails.logger.formatter
+
+    ActiveSupport.on_load :solid_queue_record do
+      # Once SolidQueue is loaded, we can broadcast its logs to the console, too.
+      # Due to the initialization order, this will effectively start logging once SolidQueue is about to start.
+      Rails.logger.broadcast_to console
+    end
+  end
+end
diff --git a/db/migrate/20240609104039_create_solid_queue_tables.solid_queue.rb b/db/migrate/20240609104039_create_solid_queue_tables.solid_queue.rb
new file mode 100644
index 000000000..874f68ba0
--- /dev/null
+++ b/db/migrate/20240609104039_create_solid_queue_tables.solid_queue.rb
@@ -0,0 +1,103 @@
+# frozen_string_literal: true
+
+# This migration comes from solid_queue (originally 20231211200639)
+class CreateSolidQueueTables < ActiveRecord::Migration[7.0]
+  def change
+    create_table :solid_queue_jobs do |t|
+      t.string :queue_name, null: false
+      t.string :class_name, null: false, index: true
+      t.text :arguments
+      t.integer :priority, default: 0, null: false
+      t.string :active_job_id, index: true
+      t.datetime :scheduled_at
+      t.datetime :finished_at, index: true
+      t.string :concurrency_key
+
+      t.timestamps
+
+      t.index %i[queue_name finished_at], name: 'index_solid_queue_jobs_for_filtering'
+      t.index %i[scheduled_at finished_at], name: 'index_solid_queue_jobs_for_alerting'
+    end
+
+    create_table :solid_queue_scheduled_executions do |t|
+      t.references :job, index: {unique: true}, null: false
+      t.string :queue_name, null: false
+      t.integer :priority, default: 0, null: false
+      t.datetime :scheduled_at, null: false
+
+      t.datetime :created_at, null: false
+
+      t.index %i[scheduled_at priority job_id], name: 'index_solid_queue_dispatch_all'
+    end
+
+    create_table :solid_queue_ready_executions do |t|
+      t.references :job, index: {unique: true}, null: false
+      t.string :queue_name, null: false
+      t.integer :priority, default: 0, null: false
+
+      t.datetime :created_at, null: false
+
+      t.index %i[priority job_id], name: 'index_solid_queue_poll_all'
+      t.index %i[queue_name priority job_id], name: 'index_solid_queue_poll_by_queue'
+    end
+
+    create_table :solid_queue_claimed_executions do |t|
+      t.references :job, index: {unique: true}, null: false
+      t.bigint :process_id
+      t.datetime :created_at, null: false
+
+      t.index %i[process_id job_id]
+    end
+
+    create_table :solid_queue_blocked_executions do |t|
+      t.references :job, index: {unique: true}, null: false
+      t.string :queue_name, null: false
+      t.integer :priority, default: 0, null: false
+      t.string :concurrency_key, null: false
+      t.datetime :expires_at, null: false
+
+      t.datetime :created_at, null: false
+
+      t.index %i[expires_at concurrency_key], name: 'index_solid_queue_blocked_executions_for_maintenance'
+    end
+
+    create_table :solid_queue_failed_executions do |t|
+      t.references :job, index: {unique: true}, null: false
+      t.text :error
+      t.datetime :created_at, null: false
+    end
+
+    create_table :solid_queue_pauses do |t|
+      t.string :queue_name, null: false, index: {unique: true}
+      t.datetime :created_at, null: false
+    end
+
+    create_table :solid_queue_processes do |t|
+      t.string :kind, null: false
+      t.datetime :last_heartbeat_at, null: false, index: true
+      t.bigint :supervisor_id, index: true
+
+      t.integer :pid, null: false
+      t.string :hostname
+      t.text :metadata
+
+      t.datetime :created_at, null: false
+    end
+
+    create_table :solid_queue_semaphores do |t|
+      t.string :key, null: false, index: {unique: true}
+      t.integer :value, default: 1, null: false
+      t.datetime :expires_at, null: false, index: true
+
+      t.timestamps
+
+      t.index %i[key value], name: 'index_solid_queue_semaphores_on_key_and_value'
+    end
+
+    add_foreign_key :solid_queue_blocked_executions, :solid_queue_jobs, column: :job_id, on_delete: :cascade
+    add_foreign_key :solid_queue_claimed_executions, :solid_queue_jobs, column: :job_id, on_delete: :cascade
+    add_foreign_key :solid_queue_failed_executions, :solid_queue_jobs, column: :job_id, on_delete: :cascade
+    add_foreign_key :solid_queue_ready_executions, :solid_queue_jobs, column: :job_id, on_delete: :cascade
+    add_foreign_key :solid_queue_scheduled_executions, :solid_queue_jobs, column: :job_id, on_delete: :cascade
+  end
+end
diff --git a/db/migrate/20240609104040_add_missing_index_to_blocked_executions.solid_queue.rb b/db/migrate/20240609104040_add_missing_index_to_blocked_executions.solid_queue.rb
new file mode 100644
index 000000000..491e2181d
--- /dev/null
+++ b/db/migrate/20240609104040_add_missing_index_to_blocked_executions.solid_queue.rb
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+# This migration comes from solid_queue (originally 20240110143450)
+class AddMissingIndexToBlockedExecutions < ActiveRecord::Migration[7.1]
+  def change
+    add_index :solid_queue_blocked_executions, %i[concurrency_key priority job_id], name: 'index_solid_queue_blocked_executions_for_release'
+  end
+end
diff --git a/db/migrate/20240609104041_create_recurring_executions.solid_queue.rb b/db/migrate/20240609104041_create_recurring_executions.solid_queue.rb
new file mode 100644
index 000000000..69847c125
--- /dev/null
+++ b/db/migrate/20240609104041_create_recurring_executions.solid_queue.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+# This migration comes from solid_queue (originally 20240218110712)
+class CreateRecurringExecutions < ActiveRecord::Migration[7.1]
+  def change
+    create_table :solid_queue_recurring_executions do |t|
+      t.references :job, index: {unique: true}, null: false
+      t.string :task_key, null: false
+      t.datetime :run_at, null: false
+      t.datetime :created_at, null: false
+
+      t.index %i[task_key run_at], unique: true
+    end
+
+    add_foreign_key :solid_queue_recurring_executions, :solid_queue_jobs, column: :job_id, on_delete: :cascade
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index d3f99fb0f..d5afcfd38 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2024_05_31_160738) do
+ActiveRecord::Schema[7.1].define(version: 2024_06_09_104041) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pgcrypto"
   enable_extension "plpgsql"
@@ -199,6 +199,109 @@
     t.index ["user_id"], name: "index_reports_on_user_id"
   end
 
+  create_table "solid_queue_blocked_executions", force: :cascade do |t|
+    t.bigint "job_id", null: false
+    t.string "queue_name", null: false
+    t.integer "priority", default: 0, null: false
+    t.string "concurrency_key", null: false
+    t.datetime "expires_at", null: false
+    t.datetime "created_at", null: false
+    t.index ["concurrency_key", "priority", "job_id"], name: "index_solid_queue_blocked_executions_for_release"
+    t.index ["expires_at", "concurrency_key"], name: "index_solid_queue_blocked_executions_for_maintenance"
+    t.index ["job_id"], name: "index_solid_queue_blocked_executions_on_job_id", unique: true
+  end
+
+  create_table "solid_queue_claimed_executions", force: :cascade do |t|
+    t.bigint "job_id", null: false
+    t.bigint "process_id"
+    t.datetime "created_at", null: false
+    t.index ["job_id"], name: "index_solid_queue_claimed_executions_on_job_id", unique: true
+    t.index ["process_id", "job_id"], name: "index_solid_queue_claimed_executions_on_process_id_and_job_id"
+  end
+
+  create_table "solid_queue_failed_executions", force: :cascade do |t|
+    t.bigint "job_id", null: false
+    t.text "error"
+    t.datetime "created_at", null: false
+    t.index ["job_id"], name: "index_solid_queue_failed_executions_on_job_id", unique: true
+  end
+
+  create_table "solid_queue_jobs", force: :cascade do |t|
+    t.string "queue_name", null: false
+    t.string "class_name", null: false
+    t.text "arguments"
+    t.integer "priority", default: 0, null: false
+    t.string "active_job_id"
+    t.datetime "scheduled_at"
+    t.datetime "finished_at"
+    t.string "concurrency_key"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["active_job_id"], name: "index_solid_queue_jobs_on_active_job_id"
+    t.index ["class_name"], name: "index_solid_queue_jobs_on_class_name"
+    t.index ["finished_at"], name: "index_solid_queue_jobs_on_finished_at"
+    t.index ["queue_name", "finished_at"], name: "index_solid_queue_jobs_for_filtering"
+    t.index ["scheduled_at", "finished_at"], name: "index_solid_queue_jobs_for_alerting"
+  end
+
+  create_table "solid_queue_pauses", force: :cascade do |t|
+    t.string "queue_name", null: false
+    t.datetime "created_at", null: false
+    t.index ["queue_name"], name: "index_solid_queue_pauses_on_queue_name", unique: true
+  end
+
+  create_table "solid_queue_processes", force: :cascade do |t|
+    t.string "kind", null: false
+    t.datetime "last_heartbeat_at", null: false
+    t.bigint "supervisor_id"
+    t.integer "pid", null: false
+    t.string "hostname"
+    t.text "metadata"
+    t.datetime "created_at", null: false
+    t.index ["last_heartbeat_at"], name: "index_solid_queue_processes_on_last_heartbeat_at"
+    t.index ["supervisor_id"], name: "index_solid_queue_processes_on_supervisor_id"
+  end
+
+  create_table "solid_queue_ready_executions", force: :cascade do |t|
+    t.bigint "job_id", null: false
+    t.string "queue_name", null: false
+    t.integer "priority", default: 0, null: false
+    t.datetime "created_at", null: false
+    t.index ["job_id"], name: "index_solid_queue_ready_executions_on_job_id", unique: true
+    t.index ["priority", "job_id"], name: "index_solid_queue_poll_all"
+    t.index ["queue_name", "priority", "job_id"], name: "index_solid_queue_poll_by_queue"
+  end
+
+  create_table "solid_queue_recurring_executions", force: :cascade do |t|
+    t.bigint "job_id", null: false
+    t.string "task_key", null: false
+    t.datetime "run_at", null: false
+    t.datetime "created_at", null: false
+    t.index ["job_id"], name: "index_solid_queue_recurring_executions_on_job_id", unique: true
+    t.index ["task_key", "run_at"], name: "index_solid_queue_recurring_executions_on_task_key_and_run_at", unique: true
+  end
+
+  create_table "solid_queue_scheduled_executions", force: :cascade do |t|
+    t.bigint "job_id", null: false
+    t.string "queue_name", null: false
+    t.integer "priority", default: 0, null: false
+    t.datetime "scheduled_at", null: false
+    t.datetime "created_at", null: false
+    t.index ["job_id"], name: "index_solid_queue_scheduled_executions_on_job_id", unique: true
+    t.index ["scheduled_at", "priority", "job_id"], name: "index_solid_queue_dispatch_all"
+  end
+
+  create_table "solid_queue_semaphores", force: :cascade do |t|
+    t.string "key", null: false
+    t.integer "value", default: 1, null: false
+    t.datetime "expires_at", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["expires_at"], name: "index_solid_queue_semaphores_on_expires_at"
+    t.index ["key", "value"], name: "index_solid_queue_semaphores_on_key_and_value"
+    t.index ["key"], name: "index_solid_queue_semaphores_on_key", unique: true
+  end
+
   create_table "taggings", id: :serial, force: :cascade do |t|
     t.integer "tag_id"
     t.string "taggable_type"
@@ -350,6 +453,12 @@
   add_foreign_key "ratings", "users"
   add_foreign_key "reports", "tasks"
   add_foreign_key "reports", "users"
+  add_foreign_key "solid_queue_blocked_executions", "solid_queue_jobs", column: "job_id", on_delete: :cascade
+  add_foreign_key "solid_queue_claimed_executions", "solid_queue_jobs", column: "job_id", on_delete: :cascade
+  add_foreign_key "solid_queue_failed_executions", "solid_queue_jobs", column: "job_id", on_delete: :cascade
+  add_foreign_key "solid_queue_ready_executions", "solid_queue_jobs", column: "job_id", on_delete: :cascade
+  add_foreign_key "solid_queue_recurring_executions", "solid_queue_jobs", column: "job_id", on_delete: :cascade
+  add_foreign_key "solid_queue_scheduled_executions", "solid_queue_jobs", column: "job_id", on_delete: :cascade
   add_foreign_key "task_labels", "tasks"
   add_foreign_key "tasks", "licenses"
   add_foreign_key "tests", "tasks"
diff --git a/docs/LOCAL_SETUP.md b/docs/LOCAL_SETUP.md
index 14d419740..a894ea281 100644
--- a/docs/LOCAL_SETUP.md
+++ b/docs/LOCAL_SETUP.md
@@ -181,7 +181,9 @@ rake db:setup
 
 ### Start CodeHarbor
 
-For the development environment, two server processes are required: the Rails server for the main application and a Webpack server providing JavaScript and CSS assets.
+For the development environment, three server processes are required: 
+the Rails server for the main application, a Webpack server providing JavaScript and CSS assets
+and the Solid Queue supervisor to process background jobs.
 
 1. Webpack dev server:
 
@@ -201,6 +203,15 @@ This will launch a dedicated server on port 3045 (default setting) and allow inc
 
 This will launch the CodeHarbor web application server on port 7500 (default setting) and allow incoming connections from your browser.
 
+3. Solid Queue supervisor (optional):
+
+  ```shell
+  bundle exec rake solid_queue:start
+  ```
+  
+Solid Queue is currently only used to synchronize task metadata with the "NBP Datenraum".
+The synchronization is disabled by default. Unless you enable it, you can skip starting the supervisor.
+
 **Check with:**  
 Open your web browser at <http://localhost:7500>
 
diff --git a/lib/nbp/push_connector.rb b/lib/nbp/push_connector.rb
new file mode 100644
index 000000000..0151c1f13
--- /dev/null
+++ b/lib/nbp/push_connector.rb
@@ -0,0 +1,114 @@
+# frozen_string_literal: true
+
+module Nbp
+  class SettingsError < StandardError; end
+  class ConnectorError < StandardError; end
+
+  class PushConnector
+    include Singleton
+
+    def initialize
+      super
+      create_source! unless source_exists?
+    end
+
+    def self.enabled?
+      Settings.nbp&.push_connector&.enable || false
+    end
+
+    def push_lom!(xml)
+      response = api_conn.put("/push-connector/api/lom-v2/#{settings.source.slug}") do |req|
+        req.body = {metadata: xml}.to_json
+      end
+      raise_connector_error('Could not push task LOM', response) unless success_status?(response.status)
+    end
+
+    def delete_task!(task_uuid)
+      response = api_conn.delete("/push-connector/api/course/#{settings.source.slug}/#{task_uuid}")
+      raise_connector_error('Could delete task', response) unless success_status?(response.status) || response.status == 404
+    end
+
+    def source_exists?
+      response = api_conn.get("/datenraum/api/core/sources/slug/#{settings.source.slug}")
+      if response.status == 200
+        true
+      elsif response.status == 404
+        false
+      else
+        raise_connector_error('Could not determine if source exists', response)
+      end
+    end
+
+    def create_source!
+      response = api_conn.post('/datenraum/api/core/sources') do |req|
+        req.body = settings.source.to_json
+      end
+      raise_connector_error('Failed to create source', response) unless success_status?(response.status)
+    end
+
+    def token
+      if @token.present? && @token_expiration > 10.seconds.from_now
+        @token
+      else
+        update_token
+      end
+    end
+
+    def update_token
+      response = Faraday.post(settings.token_path, auth)
+      result = JSON.parse(response.body)
+
+      if success_status?(response.status)
+        @token_expiration = Time.zone.now + result['expires_in']
+        @token = result['access_token']
+      else
+        raise_connector_error('Failed to get fresh access token', response)
+      end
+    end
+
+    def auth
+      {
+        grant_type: 'client_credentials',
+        client_id: settings.client_id,
+        client_secret: settings.client_secret,
+      }
+    end
+
+    def api_conn
+      Faraday.new(url: settings.api_host, headers:)
+    end
+
+    def settings
+      return @connector_settings if @connector_settings
+
+      check_settings!
+      @connector_settings = Settings.nbp&.push_connector
+    end
+
+    def check_settings! # rubocop:disable Metrics/AbcSize
+      settings_hash = Settings.nbp&.push_connector.to_h
+
+      if PushConnector.enabled?
+        missing_keys = %i[client_id client_secret token_path api_host source] - settings_hash.keys
+        raise SettingsError.new("Nbp::PushConnector is missing some settings: #{missing_keys}") if missing_keys.any?
+
+        missing_source_keys = %i[organization name slug] - settings_hash[:source].keys
+        raise SettingsError.new("Nbp::PushConnector source is missing some settings: #{missing_source_keys}") if missing_source_keys.any?
+      else
+        raise SettingsError.new('Nbp::PushConnector is disabled but got accessed')
+      end
+    end
+
+    def success_status?(status_code)
+      (200..299).cover?(status_code)
+    end
+
+    def raise_connector_error(message, faraday_response)
+      raise ConnectorError.new("#{message} (code #{faraday_response.status}). Response was: '#{faraday_response.body}'")
+    end
+
+    def headers
+      {authorization: "Bearer #{token}", 'content-type': 'application/json', accept: 'application/json'}
+    end
+  end
+end
diff --git a/lib/tasks/nbp_push_all_tasks.rake b/lib/tasks/nbp_push_all_tasks.rake
new file mode 100644
index 000000000..19e011b16
--- /dev/null
+++ b/lib/tasks/nbp_push_all_tasks.rake
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+namespace :nbp do
+  desc 'Pushes all tasks to the NBP for an initial sync'
+  task push_all: :environment do
+    NbpPushAllJob.perform_later
+  end
+end
diff --git a/spec/lib/nbp/push_connector_spec.rb b/spec/lib/nbp/push_connector_spec.rb
new file mode 100644
index 000000000..beca53fec
--- /dev/null
+++ b/spec/lib/nbp/push_connector_spec.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Nbp::PushConnector do
+  let(:api_host) { Settings.nbp.push_connector.api_host }
+  let(:source_slug) { Settings.nbp.push_connector.source.slug }
+
+  let(:task) { create(:task) }
+  let(:task_xml) { (Nokogiri::XML::Builder.new(encoding: 'UTF-8') {|xml| LomService::ExportLom.call(task:, xml:) }).to_xml }
+
+  let(:connector) { Class.new(described_class).instance } # https://stackoverflow.com/a/23901644
+
+  before do
+    stub_request(:post, Settings.nbp.push_connector.token_path).to_return_json(body: {token: 'sometoken', expires_in: 600})
+    stub_request(:post, "#{api_host}/datenraum/api/core/sources")
+    stub_request(:put, "#{api_host}/push-connector/api/lom-v2/#{source_slug}")
+    stub_request(:get, "#{api_host}/datenraum/api/core/sources/slug/#{source_slug}").to_return(status: 404)
+  end
+
+  describe 'push_lom!' do
+    subject(:push_lom!) { connector.push_lom!(task_xml) }
+
+    context 'when no source exists' do
+      it 'creates a source' do
+        push_lom!
+        expect(WebMock).to have_requested(:post, "#{api_host}/datenraum/api/core/sources")
+      end
+    end
+
+    context 'when a source exists' do
+      before { stub_request(:get, "#{api_host}/datenraum/api/core/sources/slug/#{source_slug}").to_return(status: 200) }
+
+      it 'does not create a source' do
+        push_lom!
+        expect(WebMock).not_to have_requested(:post, "#{api_host}/datenraum/api/core/sources")
+      end
+    end
+
+    context 'without any errors' do
+      it 'pushes the metadata' do
+        push_lom!
+        expect(WebMock).to have_requested(:put, "#{api_host}/push-connector/api/lom-v2/#{source_slug}")
+      end
+    end
+  end
+end
diff --git a/spec/models/task_spec.rb b/spec/models/task_spec.rb
index b3e5ea0f4..e413dd24d 100644
--- a/spec/models/task_spec.rb
+++ b/spec/models/task_spec.rb
@@ -3,6 +3,8 @@
 require 'rails_helper'
 
 RSpec.describe Task do
+  include ActiveJob::TestHelper
+
   describe '#valid?' do
     it { is_expected.to validate_presence_of(:title) }
     it { is_expected.to validate_uniqueness_of(:uuid).case_insensitive }
@@ -186,5 +188,51 @@
       destroy
       expect(collection.reload.tasks).to be_empty
     end
+
+    it 'enqueues an NbpDeleteJob' do
+      expect { destroy }.to have_enqueued_job(NbpDeleteJob).with(task.uuid)
+    end
+  end
+
+  describe '#update' do
+    subject(:update) { task.update(new_attributes) }
+
+    let(:task) { create(:task, access_level:) }
+
+    context 'when updating a public task' do
+      let(:access_level) { :public }
+      let(:new_attributes) { {title: 'some new title'} }
+
+      it 'enqueues an NbpPushJob' do
+        expect { update }.to have_enqueued_job(NbpPushJob).with(task)
+      end
+    end
+
+    context 'when updating a private task' do
+      let(:access_level) { :private }
+      let(:new_attributes) { {title: 'some new title'} }
+
+      it 'does not enqueue an NbpPushJob' do
+        expect { update }.not_to have_enqueued_job(NbpPushJob)
+      end
+    end
+
+    context 'when changing the access level from private to public' do
+      let(:access_level) { :private }
+      let(:new_attributes) { {access_level: :public} }
+
+      it 'enqueues an NbpPushJob' do
+        expect { update }.to have_enqueued_job(NbpPushJob).with(task)
+      end
+    end
+
+    context 'when changing the access level from public to private' do
+      let(:access_level) { :public }
+      let(:new_attributes) { {access_level: :private} }
+
+      it 'enqueues an NbpDeleteJob' do
+        expect { update }.to have_enqueued_job(NbpDeleteJob).with(task.uuid)
+      end
+    end
   end
 end