Parameter Types

Reference for Tekton parameter types and usage

Parameters allow you to pass values into Tasks and Pipelines at runtime.

ParamSpec

Defines a parameter declaration in a Task or Pipeline.

name · string · required

Name by which the parameter is referenced.

Must be a valid identifier (alphanumeric with hyphens and underscores).

type · ParamType · default: "string"

Type of the parameter.

Values:

• string - Single string value
• array - Array of strings
• object - Key-value pairs

description · string

Human-readable description of the parameter.

default · ParamValue

Default value if not supplied at runtime.

If default is set, the parameter becomes optional.

properties · map[string]PropertySpec

For object-type parameters, defines the structure of allowed keys.

Show PropertySpec fields

type · ParamType · default: "string"

Type of this property (typically string).

enum · []string

List of allowed values for string parameters.

Requires the enable-param-enum feature flag.

params:
  - name: environment
    type: string
    enum: ["dev", "staging", "prod"]

Param

Provides a value for a parameter.

name · string · required

Name of the parameter being set.

value · ParamValue · required

The value to pass to the parameter.

ParamValue

A ParamValue can hold different types of values:

String Value

params:
  - name: message
    value: "Hello World"

Array Value

params:
  - name: flags
    value:
      - "--verbose"
      - "--debug"

Object Value

params:
  - name: config
    value:
      host: "example.com"
      port: "8080"
      protocol: "https"

Variable Substitution

Parameters can be referenced using variable substitution syntax:

String Parameters

steps:
  - name: echo
    image: ubuntu
    script: |
      echo "$(params.message)"

Array Parameters

Reference the entire array:

args: ["$(params.flags[*])"]

Reference individual elements:

args: ["$(params.flags[0])", "$(params.flags[1])"]

Object Parameters

Access individual keys:

script: |
  curl $(params.config.protocol)://$(params.config.host):$(params.config.port)

Parameter Propagation

Pipeline to Task

Pass Pipeline parameters to Tasks:

apiVersion: tekton.dev/v1
kind: Pipeline
spec:
  params:
    - name: repo-url
      type: string
  tasks:
    - name: clone
      taskRef:
        name: git-clone
      params:
        - name: url
          value: $(params.repo-url)

Using Task Results as Parameters

Pass task results to subsequent tasks:

tasks:
  - name: get-version
    taskRef:
      name: read-version
  - name: build
    taskRef:
      name: build-image
    params:
      - name: version
        value: $(tasks.get-version.results.version)
    runAfter:
      - get-version

Object Parameter Example

apiVersion: tekton.dev/v1
kind: Task
metadata:
  name: use-object-param
spec:
  params:
    - name: database
      type: object
      properties:
        host:
          type: string
        port:
          type: string
        name:
          type: string
      default:
        host: "localhost"
        port: "5432"
        name: "mydb"
  steps:
    - name: connect
      image: postgres
      script: |
        psql -h $(params.database.host) \
             -p $(params.database.port) \
             -d $(params.database.name)

Array Parameter Example

apiVersion: tekton.dev/v1
kind: Task
metadata:
  name: use-array-param
spec:
  params:
    - name: build-args
      type: array
      description: Build arguments for docker build
      default:
        - "--no-cache"
  steps:
    - name: build
      image: docker
      args:
        - "build"
        - "$(params.build-args[*])"
        - "."

Default Values

Parameters with defaults are optional:

params:
  - name: revision
    type: string
    description: Git revision to checkout
    default: "main"
  - name: verbose
    type: string
    default: "false"

Best Practices

1. Always provide descriptions - Help users understand parameter purpose
2. Use meaningful names - Choose clear, descriptive parameter names
3. Set sensible defaults - Make parameters optional when reasonable
4. Use object params for related values - Group related configuration
5. Validate in scripts - Add validation logic for parameter values
6. Document expected formats - Specify format in description (e.g., URLs, versions)