add tasks / job to migrate pjs under namespace

app/jobs/pjs_migration_job.rb

@@ -0,0 +1,31 @@
+class PjsMigrationJob < ApplicationJob
+  queue_as :pj_migration_jobs
+
+  def perform(blob_id)
+    blob = Blob.find(blob_id)
+
+    return if already_moved?(blob)
+
+    service = blob.service
+    client = service.client
+    container = service.container
+    old_key = blob.key
+    new_key = "#{blob.created_at.year}/#{old_key[0..1]}/#{old_key[2..3]}/#{old_key}"
+
+    excon_response = client.copy_object(container,
+                               old_key,
+                               container,
+                               new_key,
+                               { "Content-Type" => blob.content_type })
+
+    if excon_response.status == 201
+      blob.update_columns(key: new_key)
+      client.delete_object(container, old_key)
+    end
+  rescue Fog::OpenStack::Storage::NotFound
+  end
+
+  def already_moved?(blob)
+    blob.key.include?('/')
+  end
+end

lib/tasks/pjs.rake

@@ -0,0 +1,25 @@
+namespace :pjs do
+  task stats: :environment do
+  end
+
+  desc <<~EOD
+    bin/rake 'pjs:migrate['aa']'
+    bin/rake 'pjs:migrate['aa-ab-ac']'
+  EOD
+  task :migrate, [:prefixes] => :environment do |_t, args|
+    # [a-b] => "key LIKE 'a%' or key LIKE 'b%'"
+    prefix_like_query = args[:prefixes]
+      .split('-')
+      .map { "key LIKE '#{_1}%'" }
+      .join(' or ')
+
+    blobs = ActiveStorage::Blob
+      .where(prefix_like_query)
+      .where.not("key LIKE '%/%'") # do not touch already moved blob
+
+    blobs_count = blobs.count
+    rake_puts "targeted prefix: #{args[:prefixes]}, #{blobs_count} blobs"
+
+    blobs.in_batches { |batch| batch.ids.each { |id| PjsMigrationJob.perform_later(id) } }
+  end
+end