yaml_variables.yml

# This example workflow demonstrates how to define & refer to YAML variables in workflows.
#
# Workflows in the Civis Platform are written in YAML and a workflow DSL
# (domain specific language) called Mistral.
#
# See this website, https://docs.ansible.com/ansible/latest/reference_appendices/YAMLSyntax.html,
# for an introduction to YAML.
#
# See the Mistral documentation, https://docs.openstack.org/mistral/train/user/wf_lang_v2.html,
# for a description of the Mistral DSL.

version: '2.0'  # you always need this key to specify version 2 of the mistral DSL
workflow:
  input:
    # Before the value, prefix the variable name with &
    - city_name: &city_name Seattle

    # The variable name doesn't have to match the yaml name
    - state: &default_state WA

  # Variables can be multi-line using a pipe
  # but not as part of the input block
  source: &source |
    import os
    print(os.environ['CITY_NAME'], os.environ['STATE'])

  tasks:
    variable:
      action: civis.scripts.python3
      input:
        params:
          - name: 'CITY_NAME'
            type: 'string'
            # reference variables with *
            default: *city_name
          - name: 'STATE'
            type: 'string'
            default: *default_state
        source: *source

    variable_2:
      action: civis.scripts.python3
      input:
        params:
          - name: 'CITY_NAME'
            type: 'string'
            default: 'Washington'
          - name: 'STATE'
            type: 'string'
            default: 'DC'
        source: *source