Run CWL workflows using Xenon
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Run CWL workflows using Xenon. Possibly through a REST api.


To run a workflow through Xenon-flow is quite simple:

Xenon-flow Usage Pattern


1. Install the dependencies:

  • Java 8

2. Download Xenon-flow


3. Configure the server

Configuration of the server is done by editing the XENONFLOW_HOME/config/config.yml file. As well as the XENONFLOW_HOME/config/

By default it is set the use the local file system as the source and the local computer to run workflows.


Xenon-flow configuration consists of

  1. sourceFileSystem: Any filesystem supported by Xenon can be used here
  2. targetFileSystem: Any filesystem supported by Xenon can be used here
  3. ComputeResources: A map of compute resource descriptions for Xenon
  4. Each resource has the following settings:
    1. cwlCommand: A script to run the cwl runner, allowing for python environments to be started first.
      • Default:
         #!/usr/bin/env bash
         cwltool $@
    2. scheduler: A Xenon scheduler
    3. filesystem A Xenon filesystem
    4. Both the scheduler and filesystem have to following format:
      1. adaptor: The name of the Xenon adaptor (for instance slurm for scheduler or sftp for filesystem)
      2. location: The URI for the resource
      3. credential: Optional credentials (if not supplied the current user and ~/.ssh/id_rsa is used)
        1. user: Username
        2. password: Password in base64 encoded
      4. properties: Optional properties (usually not needed)

The needs configuration for the following things:

  1. api-key
    1. xenonflow.http.auth-token-header-name controls the name of the header that holds the api key
    2. xenonflow.http.auth-token the value of the api key. IMPORTANT you should really change this one
  2. The Database Configuration.
    • These settings should be changed!
    1. spring.datasource.username The database username
    2. spring.datasource.password The database password
  3. The SSL Configuration
    1. server.port The port for the server to run on.
    2. local.server.address=localhost The servername.
    3. server.ssl.key-store-type The keystore type (spring boot only supports PKCS12).
    • The following really need to be changed
    1. server.ssl.key-store The store for the certificate files.
    2. server.ssl.key-store-password The password to the key store.
    3. server.ssl.key-alias The alias as given to the keystore.
    4. server.http.interface Set up the server to be publicaly available by setting this to

4. Start the server

The following command will run the server.


5. Run a workflow

Put the workflow and any input files and directories to into the location as defined by the sourceFileSystem in the config. For instance when using a webdav server, upload the files there.

Send a POST http request with a job description to the server.


Given the echo command-line-tool (in yaml notation):

cwlVersion: v1.0
class: CommandLineTool
  - id: inp
    type: string
    inputBinding: {}

  - id: out
    type: string
      glob: out.txt
      loadContents: true
      outputEval: $(self[0].contents)

baseCommand: echo
stdout: out.txt

The job description looks something like the following.

Note that the input map contains a key inp which refers to the corresponding input of the echo command-line-tool.

    "name": "My First Workflow",
    "workflow": "cwl/echo.cwl",
    "input": {
        "inp": "Hello CWL Server!"
curl -X POST -H "Content-Type: application/json" -H "api-key: <insert api key here>" -d '{"name": "My First Workflow","workflow": "$PWD/cwl/echo.cwl","input": {"inp": "Hello CWL Server!"}}' https://localhost:8443/jobs