silverstripe / deploynaut

			// Disallow concurrent deployments (don't rely on queuing implementation to restrict this)

			// Only consider deployments started in the last 30 minutes (older jobs probably got stuck)

			$runningDeployments = $environment->runningDeployments()->exclude('ID', $this->args['deploymentID']);

			if($runningDeployments->count()) {

				$runningDeployment = $runningDeployments->first();

				$log->write(sprintf(

					'[-] Error: another deployment is in progress (started at %s by %s)',

					$runningDeployment->dbObject('Created')->Nice(),

					$runningDeployment->Deployer()->Title

				));

				throw new RuntimeException(sprintf(

					'Another deployment is in progress (started at %s by %s)',

					$runningDeployment->dbObject('Created')->Nice(),

					$runningDeployment->Deployer()->Title

				));

			}

			$environment->Backend()->deploy(

				$environment,

				))

				->exclude('ID', $dataTransfer->ID);

			if($runningTransfers->count()) {

				$runningTransfer = $runningTransfers->first();

				$log->write(sprintf(

					'[-] Error: another transfer is in progress (started at %s by %s)',

					$runningTransfer->dbObject('Created')->Nice(),

					$runningTransfer->Author()->Title

				));

				throw new RuntimeException(sprintf(

					'Another transfer is in progress (started at %s by %s)',

					$runningTransfer->dbObject('Created')->Nice(),

					$runningTransfer->Author()->Title

				));

			}

			// before we push data to an environment, we'll make a backup first