discourse/lib/backup_restore.rb

141 lines
3.1 KiB
Ruby

require_dependency "export/exporter"
require_dependency "import/importer"
module BackupRestore
class OperationRunningError < RuntimeError; end
DUMP_FILE = "dump.sql"
METADATA_FILE = "meta.json"
def self.backup!(user_id, publish_to_message_bus = false)
exporter = Export::Exporter.new(user_id, publish_to_message_bus)
start! exporter
end
def self.restore!(user_id, filename, publish_to_message_bus = false)
importer = Import::Importer.new(user_id, filename, publish_to_message_bus)
start! importer
end
def self.rollback!
raise BackupRestore::OperationRunningError if BackupRestore.is_operation_running?
if can_rollback?
rename_schema("backup", "public")
establish_app
end
end
def self.cancel!
set_shutdown_signal!
true
end
def self.mark_as_running!
# TODO: should acquire a lock and raise an exception if already running!
$redis.set(running_key, "1")
end
def self.is_operation_running?
!!$redis.get(running_key)
end
def self.mark_as_not_running!
$redis.del(running_key)
end
def self.should_shutdown?
!!$redis.get(shutdown_signal_key)
end
def self.can_rollback?
backup_tables_count > 0
end
def self.operations_status
{
is_operation_running: is_operation_running?,
can_rollback: can_rollback?,
}
end
def self.current_version
ActiveRecord::Migrator.current_version
end
def self.can_rollback?
User.exec_sql("SELECT 1 FROM pg_namespace WHERE nspname = 'backup'").count > 0
end
def self.rename_schema(old_name, new_name)
sql = <<-SQL
BEGIN;
DROP SCHEMA IF EXISTS #{new_name} CASCADE;
ALTER SCHEMA #{old_name} RENAME TO #{new_name};
COMMIT;
SQL
User.exec_sql(sql)
end
private
def self.running_key
"backup_restore_operation_is_running"
end
def self.shutdown_signal_key
"backup_restore_operation_should_shutdown"
end
def self.set_shutdown_signal!
$redis.set(shutdown_signal_key, "1")
end
def self.clear_shutdown_signal!
$redis.del(shutdown_signal_key)
end
def self.start!(runner)
child = fork do
begin
after_fork
runner.run
rescue Exception => e
puts "--------------------------------------------"
puts "---------------- EXCEPTION -----------------"
puts e.message
puts e.backtrace.join("\n")
puts "--------------------------------------------"
ensure
begin
clear_shutdown_signal!
rescue Exception => e
puts "============================================"
puts "================ EXCEPTION ================="
puts e.message
puts e.backtrace.join("\n")
puts "============================================"
ensure
exit!(0)
end
end
end
Process.detach(child)
true
end
def self.after_fork
$redis.client.reconnect
Rails.cache.reconnect
MessageBus.after_fork
end
def self.backup_tables_count
User.exec_sql("SELECT COUNT(*) AS count FROM information_schema.tables WHERE table_schema = 'backup'")[0]['count'].to_i
end
end