1 files changed, 41 insertions, 0 deletions
diff --git a/lib/gitlab/database/schema_migrations/context.rb b/lib/gitlab/database/schema_migrations/context.rb
new file mode 100644
index 00000000000..bd8b9bed2c1
--- /dev/null
+++ b/lib/gitlab/database/schema_migrations/context.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    module SchemaMigrations
+      class Context
+        attr_reader :connection
+
+        def initialize(connection)
+          @connection = connection
+        end
+
+        def schema_directory
+          @schema_directory ||=
+            if ActiveRecord::Base.configurations.primary?(database_name)
+              File.join(db_dir, 'schema_migrations')
+            else
+              File.join(db_dir, "#{database_name}_schema_migrations")
+            end
+        end
+
+        def versions_to_create
+          versions_from_database = @connection.schema_migration.all_versions
+          versions_from_migration_files = @connection.migration_context.migrations.map { |m| m.version.to_s }
+
+          versions_from_database & versions_from_migration_files
+        end
+
+        private
+
+        def database_name
+          @database_name ||= @connection.pool.db_config.name
+        end
+
+        def db_dir
+          @db_dir ||= Rails.application.config.paths["db"].first
+        end
+      end
+    end
+  end
+end