Add AS migration for existing experiment images [SCI-3949]

db/migrate/20190613134100_convert_to_active_storage.rb

@@ -5,7 +5,7 @@ class ConvertToActiveStorage < ActiveRecord::Migration[5.2]
 
   ID_PARTITION_LIMIT = 1_000_000_000
   DIGEST = OpenSSL::Digest.const_get('SHA1').new
-  MODELS = [Asset, Experiment, TempFile, TinyMceAsset, User, ZipExport].freeze
+  MODELS = [Asset, TempFile, TinyMceAsset, User, ZipExport].freeze
 
   def up
     ActiveRecord::Base.connection.raw_connection.prepare('active_storage_blob_statement', <<-SQL)

db/migrate/20191009146101_convert_experiments_to_active_storage.rb

@@ -0,0 +1,103 @@
+# frozen_string_literal: true
+
+class ConvertExperimentsToActiveStorage < ActiveRecord::Migration[5.2]
+  require 'open-uri'
+
+  ID_PARTITION_LIMIT = 1_000_000_000
+  DIGEST = OpenSSL::Digest.const_get('SHA1').new
+  MODELS = [Experiment].freeze
+
+  def up
+    ActiveRecord::Base.connection.raw_connection.prepare('active_storage_blob_statement', <<-SQL)
+      INSERT INTO active_storage_blobs (
+        key, filename, content_type, metadata, byte_size, checksum, created_at
+      ) VALUES ($1, $2, $3, '{}', $4, $5, $6)
+      RETURNING id;
+    SQL
+
+    ActiveRecord::Base.connection.raw_connection.prepare('active_storage_attachment_statement', <<-SQL)
+      INSERT INTO active_storage_attachments (
+        name, record_type, record_id, blob_id, created_at
+      ) VALUES ($1, $2, $3, $4, $5)
+    SQL
+
+    transaction do
+      MODELS.each do |model|
+        next unless ActiveRecord::Base.connection.table_exists?(model.table_name)
+
+        attachments = model.column_names.map do |c|
+          $1 if c =~ /(.+)_file_name$/
+        end.compact
+
+        next if attachments.blank?
+
+        model.find_each.each do |instance|
+          attachments.each do |attachment|
+            next if instance.__send__("#{attachment}_file_name").blank?
+
+            res = ActiveRecord::Base.connection.raw_connection.exec_prepared(
+              'active_storage_blob_statement', [
+                key(instance, attachment),
+                instance.__send__("#{attachment}_file_name"),
+                instance.__send__("#{attachment}_content_type"),
+                instance.__send__("#{attachment}_file_size") || 0,
+                checksum(attachment),
+                instance.updated_at.iso8601
+              ]
+            )
+
+            ActiveRecord::Base.connection.raw_connection.exec_prepared(
+              'active_storage_attachment_statement', [
+                attachment,
+                model.name,
+                instance.id,
+                res[0]['id'],
+                instance.updated_at.iso8601
+              ]
+            )
+          end
+        end
+      end
+    end
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+
+  private
+
+  ID_PARTITION_LIMIT = 1_000_000_000
+  DIGEST = OpenSSL::Digest.const_get('SHA1').new
+
+  def id_partition(id)
+    if id < ID_PARTITION_LIMIT
+      format('%09d', id).scan(/\d{3}/).join('/')
+    else
+      format('%012d', id).scan(/\d{3}/).join('/')
+    end
+  end
+
+  def hash_data(instance, attachment)
+    "#{instance.class.to_s.underscore.pluralize}/#{attachment.pluralize}/#{instance.id}/original"
+  end
+
+  def interpolate(pattern, instance, attachment)
+    path = pattern
+    path = path.gsub(':class', instance.class.to_s.underscore.pluralize)
+    path = path.gsub(':attachment', attachment.pluralize)
+    path = path.gsub(':id_partition', id_partition(instance.id))
+    path = path.gsub(':hash', OpenSSL::HMAC.hexdigest(DIGEST,
+                                                      ENV['PAPERCLIP_HASH_SECRET'],
+                                                      hash_data(instance, attachment)))
+    path.gsub(':filename', instance.__send__("#{attachment}_file_name"))
+  end
+
+  def key(instance, attachment)
+    interpolate(':class/:attachment/:id_partition/:hash/original/:filename', instance, attachment)
+  end
+
+  def checksum(_attachment)
+    'dummy'
+  end
+end