Pipeline Parameters

Parameters let you write a single pipeline that behaves differently depending on inputs provided at runtime.

Declaring Parameters

Add a parameters: block at the top of your pipeline file:

parameters:
  - name: flavor
    description: Build configuration (debug or release)
    default: debug
  - name: upload
    description: Whether to upload the artifact after building

Field	Description
name	Key used in ${name} substitutions and --param name=value.
description	Optional. Shown in --dry-run output.
default	Optional. Value used when no --param is supplied. Omit to make the parameter required.

Using Parameters in Commands

Reference parameters with ${name} inside any task command::

tasks:
  - name: Build
    command: swift build --configuration ${flavor}
  - name: Upload
    command: ./upload.sh --flavor ${flavor}
    when: ${upload} == true

Providing Values at Runtime

Pass values on the command line:

luca run build --param flavor=release --param upload=true

Multiple --param flags are supported.

Required vs Optional Parameters

• A parameter with a default: is optional — the default is used when no --param is supplied.
• A parameter without a default: is required — Luca exits with an error if no value is provided.

Security

Parameters are passed to tasks via the process environment, not interpolated into shell text. This prevents shell injection attacks regardless of what value is supplied.

Viewing Parameters in Dry Run

--dry-run shows each parameter with its resolved value and source:

luca run build --dry-run --param flavor=release

Example output:

[DRY RUN] Pipeline: build

Parameters:
  flavor = release (override)
  upload = false (default)

See Dry Run for full output details.