Apache Airflow Upsert a Variable

arazzo: 1.0.1
info:
  title: Apache Airflow Upsert a Variable
  summary: Look up an Airflow variable and update it if it exists, otherwise create it, then read the result back.
  description: >-
    Airflow variables carry the environment-specific configuration that DAGs read
    at parse and run time, which makes "set this variable to this value, whether
    or not it already exists" one of the most common things a deployment pipeline
    asks of the API. The variables API has no upsert, so this workflow builds one:
    it looks the key up, branches on whether the lookup returned 200 or 404,
    patches or creates accordingly, and reads the value back to confirm. Every
    step spells out its request inline so the flow can be read and executed
    without opening the underlying OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: variableApi
  url: ../openapi/apache-airflow-variable-api-openapi.yml
  type: openapi
workflows:
- workflowId: upsert-variable
  summary: Create or update an Airflow variable by key.
  description: >-
    Resolves the variable by key, patches it when present and creates it when
    absent, then reads it back to verify the stored value.
  inputs:
    type: object
    required:
    - variableKey
    - value
    properties:
      variableKey:
        type: string
        description: The variable key to upsert (e.g. "warehouse_conn_target").
      value:
        type: string
        description: >-
          The variable value. Airflow stores variable values as strings; JSON
          payloads should be serialized by the caller.
      description:
        type: string
        description: A human readable description stored alongside the variable.
  steps:
  - stepId: lookupVariable
    description: >-
      Look the variable up by key. A 200 means it exists and should be patched; a
      404 means it must be created. Both outcomes are expected, so both are
      treated as success and the branch is decided on the status code.
    operationId: get_variable
    parameters:
    - name: variable_key
      in: path
      value: $inputs.variableKey
    successCriteria:
    - condition: $statusCode == 200 || $statusCode == 404
    onSuccess:
    - name: variableExists
      type: goto
      stepId: updateVariable
      criteria:
      - condition: $statusCode == 200
    - name: variableMissing
      type: goto
      stepId: createVariable
      criteria:
      - condition: $statusCode == 404
  - stepId: updateVariable
    description: >-
      Patch the existing variable. The update_mask restricts the write to the
      value and description fields, and the key in the body must match the key in
      the path.
    operationId: patch_variable
    parameters:
    - name: variable_key
      in: path
      value: $inputs.variableKey
    - name: update_mask
      in: query
      value:
      - value
      - description
    requestBody:
      contentType: application/json
      payload:
        key: $inputs.variableKey
        value: $inputs.value
        description: $inputs.description
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      key: $response.body#/key
      value: $response.body#/value
    onSuccess:
    - name: verify
      type: goto
      stepId: readBackVariable
  - stepId: createVariable
    description: >-
      Create the variable when the lookup found nothing under this key.
    operationId: post_variables
    requestBody:
      contentType: application/json
      payload:
        key: $inputs.variableKey
        value: $inputs.value
        description: $inputs.description
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      key: $response.body#/key
      value: $response.body#/value
  - stepId: readBackVariable
    description: >-
      Read the variable back and require the stored value to match what was sent,
      closing the loop on either branch.
    operationId: get_variable
    parameters:
    - name: variable_key
      in: path
      value: $inputs.variableKey
    successCriteria:
    - condition: $statusCode == 200
    - context: $response.body
      condition: $.value == $inputs.value
      type: jsonpath
    outputs:
      key: $response.body#/key
      value: $response.body#/value
      description: $response.body#/description
  outputs:
    key: $steps.readBackVariable.outputs.key
    value: $steps.readBackVariable.outputs.value
    createdKey: $steps.createVariable.outputs.key
    updatedKey: $steps.updateVariable.outputs.key