Using variables and overrides

In this guide, we’ll add a variable to the Scenario and use an override to swap the scenario command without modifying the base config. Both features work identically to the docker tutorial — this guide shows them applied to a script-based Test Plan.

Prerequisites

• Completed the “Writing a command” tutorial
• An rtf-hello-world directory in the state it was at the end of that guide

Your directory should look like this:

rtf-hello-world/
├── configs/
│   ├── environment.yaml
│   └── scenario.yaml
├── scripts/
│   └── scenario.sh
└── test-plan.yaml

Using variables

Variables allow a Test Plan to pass values into Scenario and Environment configs at runtime. See the Using variables section of the docker tutorial for a full explanation.

Let’s add a variable to configs/scenario.yaml:

name: Script scenario
description: A script scenario
# --- Add a variable definition ---
variable_definitions:
  - name: scenario_variable
    description: An example variable that the scenario expects to be defined
    default: "scenario executed with default value"
# ---------------------------------
command:
  name: scenario.sh
  kind: relative_path
  path: ../scripts/scenario.sh
# --- Use the variable ---
env_vars:
  SCENARIO_ENV: "{{ scenario_variable }}"
# ------------------------

Set a value for it in test-plan.yaml:

name: Hello World
description: A test plan created as a guide for writing test plans
# --- Add a variable value ---
variables:
  scenario_variable: "scenario executed with test plan variable"
# ----------------------------
scenario:
  from:
    kind: local
    relative_path: configs/scenario.yaml
environment:
  from:
    kind: local
    relative_path: configs/environment.yaml

Run the Test Plan:

rtf run test-plan.yaml

Output:

environment setup
Running scenario from an external file
scenario executed with test plan variable
environment teardown

The value from test-plan.yaml overrides the default in scenario.yaml. You can also pass it at the CLI:

rtf run test-plan.yaml --var scenario_variable="scenario executed with CLI variable"

Output:

environment setup
Running scenario from an external file
scenario executed with CLI variable
environment teardown

Using overrides

Overrides let you replace specific parts of a Scenario or Environment config in the Test Plan without editing the base file. See the Using overrides section of the docker tutorial for a full explanation.

Let’s create a second scenario script to override with:

touch scripts/scenario-v2.sh

Add the following to scripts/scenario-v2.sh:

#!/usr/bin/env sh

echo "Running scenario from override script"
echo "$SCENARIO_ENV"

Add an override for the scenario command in test-plan.yaml:

name: Hello World
description: A test plan created as a guide for writing test plans
variables:
  scenario_variable: "scenario executed with test plan variable"
scenario:
  from:
    kind: local
    relative_path: configs/scenario.yaml
# --- Add an override for the command ---
  overrides:
    command:
      name: scenario.sh
      kind: relative_path
      path: scripts/scenario-v2.sh
# ---------------------------------------
environment:
  from:
    kind: local
    relative_path: configs/environment.yaml

Run the Test Plan:

rtf run test-plan.yaml

Output:

environment setup
Running scenario from override script
scenario executed with test plan variable
environment teardown

The override replaces only the command — the variable_definitions and env_vars from scenario.yaml are unchanged, so SCENARIO_ENV still receives its value from scenario_variable.

Next steps

You’ve now completed the script-based test plan tutorials. To go further:

• Framework reference — full reference for all config fields
• Using file providers — manage files that your Environment and Scenario depend on