Steep 5.3.0 has been released

A new minor version of my workflow management system Steep is now available. The most notable changes in version 5.3.0 are the deprecation of the argument type argument in the process chain model and service metadata as well as the deprecation of parameters of execute actions in the workflow model. Both properties were mostly unnecessary. The argument type argument should be changed to input, and parameters of execute actions should be merged into their inputs.

This change is completely backwards compatible. Steep will automatically modify posted workflows and the configured service metadata. It will issue a warning in the log file if it encounters deprecated properties. You should migrate to the new ones as soon as possible as the deprecated ones will be removed in Steep 6.0.0 or with the workflow API 5.0.0.

Existing workflows and process chains in your database will automatically be migrated to the new model if necessary.

Steep 5.3.0 also comes with a few other improvements and fixes (see complete list below). The version has been thoroughly tested in practice over the last couple of months.

Steep is a scientific workflow management system that can execute data-driven workflows in the Cloud. It is very well suited to harness the possibilities of distributed computing in order to parallelise work and to speed up your data processing workflows, no matter how complex they are and regardless of how much data you need to process. Steep is an open-source software developed at Fraunhofer IGD. You can download the binaries and the source code of Steep from its GitHub repository.

New features

  • Allow separate SSH usernames per setup to be configured
  • Allow additional environment variables to be configured that will be passed to containers created by the Docker runtime
  • Add validator that checks for common mistakes in posted workflows. Invalid workflows will be rejected with HTTP status code 400.
  • Use new web UI by default. The old UI is now deprecated and will be removed in one of the next versions.
  • Deprecate action parameters and service arguments:
    • Parameters of execute actions are actually unnecessary because they have the same structure as inputs. I’ve decided to deprecate parameters. They will be removed in Steep 6.0.0. In the meantime, parameters of an execute action in a posted workflow will automatically be merged into its inputs. A warning will be logged.
    • The same applies to service parameters with the type argument. They are unnecessary because they can be easily mapped to inputs. I’ve deprecated the type argument and will remove it in Steep 6.0.0. For the time being, argument will automatically be replaced by input in your services.yaml file. A warning will be logged.
  • Add database migration to remove deprecated data model properties. This will rename the argument type argument in process chains to input and merge parameters of execute actions into their inputs.


  • Bump lodash from 4.17.15 to 4.17.19

Bug fixes

  • Prevent duplicate setup IDs
  • Do not throw exception in NotifyingSubmissionRegistry if VM does not exist
  • Update websocket-extensions to 0.1.4
  • Fix position of text in dropdown button

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Posted by Michel Krämer
on 24 July 2020

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