Best practices for workflows in GitHub repositories

Author(s) orcid logoAvatarSimone Leo
  • What are Workflow Best Practices

  • How does RO-Crate help?

  • Generate a workflow test using Planemo

  • Understand how testing can be automated with GitHub Actions

Time estimation: 30 minutes
Supporting Materials:
Last modification: May 23, 2023
License: Tutorial Content is licensed under Apache-2.0. The GTN Framework is licensed under MIT
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This tutorial is best viewed in a Jupyter notebook! You can load this notebook one of the following ways

Launching the notebook in Jupyter in Galaxy

  1. Instructions to Launch JupyterLab
  2. Open a Terminal in JupyterLab with File -> New -> Terminal
  3. Run wget
  4. Select the notebook that appears in the list of files on the left.

Downloading the notebook

  1. Right click one of these links: Jupyter Notebook (With Solutions), Jupyter Notebook (Without Solutions)
  2. Save Link As..

A workflow, just like any other piece of software, can be formally correct and runnable but still lack a number of additional features that might help its reusability, interoperability, understandability, etc.

One of the most useful additions to a workflow is a suite of tests, which help check that the workflow is operating as intended. A test case consists of a set of inputs and corresponding expected outputs, together with a procedure for comparing the workflow’s actual outputs with the expected ones. It might be the case, in fact, that a test may be considered successful even if the actual outputs do not match the expected ones exactly, for instance because the computation involves a certain degree of randomness, or the output includes timestamps or randomly generated identifiers. Providing documentation is also important to help understand the workflow’s purpose and mode of operation, its requirements, the effect of its parameters, etc. Even a single, well structured README file can go a long way towards getting users started with your workflow, especially if complemented by examples that include sample inputs and running instructions.


In this tutorial, you will learn how to create a git repo, and begin working with it.

  1. Community best practices
  2. Best practice repositories and RO-Crate
  3. Generating tests for your workflow
  4. Adding a GitHub workflow

Community best practices

Though the practices listed above can be considered general enough to be applicable to any kind of software, individual communities usually add their own specific sets of rules and conventions that help users quickly find their way around software projects, understand them more easily and reuse them more effectively. The Galaxy community, for instance, has a guide on best practices for maintaining workflows.

The Intergalactic Workflow Commission (IWC) is a collection of highly curated Galaxy workflows that follow best practices and conform to a specific GitHub directory layout, as specified in the guide on adding workflows. In particular, the workflow file must be accompanied by a Planemo test file with the same name but a -test.yml extension, and a test-data directory that contains the datasets used by the tests described in the test file. The guide also specifies how to fulfill other requirements such as setting a license, a creator and a version tag. A new workflow can be proposed for inclusion in the collection by opening a pull request to the IWC repository: if it passes the review and is merged, it will be published to iwc-workflows. The publication process also generates a metadata file that turns the repository into a Workflow Testing RO-Crate, which can be registered to WorkflowHub and LifeMonitor.

Best practice repositories and RO-Crate

The repo2rocrate software package allows to generate a Workflow Testing RO-Crate for a workflow repository that follows community best practices. It currently supports Galaxy (based on IWC guidelines), Nextflow and Snakemake. The tool assumes that the workflow repository is structured according to the community guidelines and generates the appropriate RO-Crate metadata for the various entities. Several command line options allow to specify additional information that cannot be automatically detected or needs to be overridden.

To try the software, we’ll clone one of the iwc-workflows repositories, whose layout is known to respect the IWC guidelines. Since it already contains an RO-Crate metadata file, we’ll delete it before running the tool.

pip install repo2rocrate
git clone
cd parallel-accession-download/
rm -fv ro-crate-metadata.json
repo2rocrate --repo-url

This adds an ro-crate-metadata.json file at the top level with metadata generated based on the tool’s knowledge of the expected repository layout. By specifying a zip file as an output, we can directly generate an RO-Crate in the format accepted by WorkflowHub and LifeMonitor:

repo2rocrate --repo-url -o ../

Generating tests for your workflow

What if you only have a workflow, but you don’t have the test layout yet? You can use Planemo to generate it.

pip install planemo

As an example we will use this simple workflow, which has only two steps: it sorts the input lines and changes them to upper case. Follow these steps to generate a test layout for it:

Hands-on: Generate Workflow Tests With Planemo
  1. Download the workflow to a file.
  2. Download this input dataset to an input.bed file.
  3. Upload the workflow to Galaxy (e.g., Galaxy Europe): from the upper menu, click on “Workflow” > “Import” > “Browse”, choose and then click “Import workflow”.
  4. Start a new history: click on the “+” button on the History panel to the right.
  5. Upload the input dataset to the new history: on the left panel, go to “Upload Data” > “Choose local files” and select input.bed, then click “Start” > “Close”.
  6. Wait for the file to finish uploading (i.e., for the loading circle on the dataset’s line in the history to disappear).
  7. Run the workflow on the input dataset: click on “Workflow” in the upper menu, locate sort-and-change-case, and click on the play button to the right.

Workflow Entry.

  1. This should take you to the workflow running page. The input slot should be already filled with input.bed since there is nothing else in the history. Click on “Run Workflow” on the upper right of the center panel.

    Workflow Run Page.

  2. Wait for the workflow execution to finish.
  3. On the upper menu, go to “User” > “Workflow Invocations”, click on the invocation corresponding to the workflow just run and copy the invocation’s ID. In my case it says “Invocation: a043e8c60873170b” on the right, where a043e8c60873170b is the ID.

    Workflow Invocation.

  4. On the upper menu, go to “User” > “Preferences” > “Manage API Key”. If you don’t have an API key yet, click the button to create a new one. Under “Current API key”, click the button to copy the API Key on the right.

    API key.

  5. Run planemo workflow_test_init --galaxy_url --from_invocation INVOCATION_ID --galaxy_user_key API_KEY, replacing INVOCATION_ID with the actual invocation ID and API_KEY with the actual API key. If you’re not using the Galaxy Europe instance, also replace with the URL of the instance you’re using.
  6. Rename sort-and-change-case-(imported-from-uploaded-file).ga to and sort-and-change-case-(imported-from-uploaded-file)-tests.yml to sort-and-change-case-tests.yml. The rest of the files generated by Planemo are under test-data.
planemo workflow_test_init --galaxy_url --from_invocation INVOCATION_ID --galaxy_user_key API_KEY

Adding a GitHub workflow

In the previous section, we have learned how to generate a test layout for an example Galaxy workflow. You can apply the same procedure to your workflow and get the file structure you need to populate the GitHub repository. One thing is still missing though: a GitHub workflow to test the Galaxy workflow automatically. At the top level of the repository, create a .github/workflows directory and place a wftest.yml file inside it with the following content:

name: Periodic workflow test
    - cron: '0 3 * * *'
    name: Test workflow
    runs-on: ubuntu-latest
    - uses: actions/checkout@v2
        fetch-depth: 1
    - uses: actions/setup-python@v1
        python-version: '3.7'
    - name: install Planemo
      run: |
        pip install --upgrade pip
        pip install planemo
    - name: run planemo test
      run: |
        planemo test --biocontainers

Replacing with the name of your actual Galaxy workflow. You can find extensive documentation on GitHub workflows on the GitHub web site. Here we’ll give some highlights:

  • the on field sets the GitHub workflow to run:
    • automatically every day at 3 AM
    • when manually dispatched
  • the steps do the following:
    • check out the GitHub repository
    • set up a Python environment
    • install Planemo
    • run planemo test on the Galaxy workflow

An example of a repository built according to the guidelines given here is simleo/ccs-bam-to-fastq-qc-crate, which realizes the Workflow Testing RO-Crate setup for BAM-to-FASTQ-QC.