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Workflows Form Inputs Library

There are various ways in which you can take input from users in IDP Workflows. All types of form input types and examples are listed in this document.

Simple text input​

Simple input with basic validations​

Example workflows.yaml

Example YAML
parameters:
  - title: Fill in some steps
    properties:
      name:
        title: Simple text input
        type: string
        description: Description about input
        maxLength: 8
        pattern: "^([a-zA-Z][a-zA-Z0-9]*)(-[a-zA-Z0-9]+)*$"
        ui:autofocus: true
        ui:help: "Hint: additional description..."

Multi-line text input​

Example workflows.yaml

Example YAML
parameters:
  - title: Fill in some steps
    properties:
      multiline:
        title: Text area input
        type: string
        description: Insert your multi line string
        ui:widget: textarea
        ui:options:
          rows: 10
        ui:help: 'Hint: Make it strong!'
        ui:placeholder: |
          a=50
          b=60
          sh << word
          > echo "Equation: a + b = 110"
          > echo $(($a + $b))
          > echo ""
          > echo "Inside Here Tag, Assignment c=110"
          > c=`expr $a + $b`
          > echo $c
          > word

Dynamically Fetch Values in Workflows​

You can dynamically fetch values in the Workflows fields using UI Pickers, which are in-built. There are two kinds of UI Pickers:

  1. Standard Workflow UI Picker
  2. API Based Dynamic Workflow UI Picker

Array options​

Array with strings​

Example workflows.yaml

Array with distinct values​

Values mentioned under enum needs to be distinct, duplicate values aren't allowed under enum.

Example YAML
parameters:
  - title: Fill in some steps
    required:
      - name
    properties:
      name:
        title: Name
        type: string
        description: Unique name of the component
      volume:
        title: Volume Type
        type: string
        description: The volume type to be used
        default: 'Cold HDD'
        enum:
          - 'Provisioned IOPS'
          - 'Cold HDD'
          - 'Throughput Optimized HDD'
          - 'Magnetic'

Arrays With Distinct Values

Array with duplicate values​

Example YAML
parameters:
  - title: Fill in some steps
    properties:
      volume_type:
        title: Volume Type
        type: string
        description: The volume type to be used
        default: gp2
        enum:
          - gp2
          - gp3
          - io1
          - io2
          - sc1
          - st1
          - standard
        enumNames:
          - 'General Purpose SSD (gp2)'
          - 'General Purpose SSD (gp3)'
          - 'Provisioned IOPS (io1)'
          - 'Provisioned IOPS (io2)'
          - 'Cold HDD (sc1)'
          - 'Throughput Optimized HDD (st1)'
          - 'Magnetic (standard)'

Arrays With Duplicate Values

A multiple choices list​

Example workflows.yaml

Example YAML
parameters:
  - title: Fill in some steps
    properties:
      name:
        title: Select environments
        type: array
        items:
          type: string
          enum:
            - production
            - staging
            - development
        uniqueItems: true
        ui:widget: checkboxes

Array with Custom Objects​

Example workflows.yaml

Example YAML
parameters:
  - title: Fill in some steps
    properties:
      arrayObjects:
        title: Array with custom objects
        type: array
        minItems: 0
        ui:options:
          addable: true
          orderable: true
          removable: true
        items:
          type: object
          properties:
            array:
              title: Array string with default value
              type: string
              default: value3
              enum:
                - value1
                - value2
                - value3
            flag:
              title: Boolean flag
              type: boolean
              ui:widget: radio
            someInput:
              title: Simple text input
              type: string

Boolean options​

Boolean​

parameters:
  - title: Fill in some steps
    properties:
      name:
        title: Checkbox boolean
        type: boolean

Boolean Yes or No options (Radio Button)​

parameters:
  - title: Fill in some steps
    properties:
      name:
        title: Yes or No options
        type: boolean
        ui:widget: radio

Boolean multiple options​

Example YAML
parameters:
  - title: Fill in some steps
    properties:
      name:
        title: Select features
        type: array
        items:
          type: boolean
          enum:
            - "Enable scraping"
            - "Enable HPA"
            - "Enable cache"
        uniqueItems: true
        ui:widget: checkboxes

Conditional Inputs in Workflows​

Conditionally set parameters​

The if keyword within the parameter uses nunjucks templating. The not keyword is unavailable; instead, use JavaScript equality. e.g.: ${{ parameters.branchName if parameters.branchName else appendTimestamp("default-branch-name-") }}

Example YAML
spec:
  parameters:
    - title: Fill in some steps
      properties:
        path:
          title: path
          type: string

  steps:
    - id: fetch
      name: Fetch template
      action: fetch:template
      input:
        url: ${{ parameters.path if parameters.path else '/root' }}

Use parameters as conditional for fields​

Example YAML
parameters:
  - title: Fill in some steps
    properties:
      includeName:
        title: Include Name?
        type: boolean
        default: true

    dependencies:
      includeName:
        allOf:
          - if:
              properties:
                includeName:
                  const: true
            then:
              properties:
                lastName:
                  title: Last Name
                  type: string

  1. One Of: Helps you create a dropdown in the Workflow, where only one of all the options available could be selected.

Example workflows.yaml

Example YAML
dependencies:
  technology:
    oneOf:
      - properties:
          technology:
            enum:
              - java
          java version:
            type: "string"
            enum:
              - java8
              - java11

  1. All Of: Helps you create a dropdown in the Workflow, where only all the options available could be selected.

Example workflows.yaml

Example YAML
type: object
allOf:
- properties:
    lorem:
      type:
      - string
      - boolean
      default: true
- properties:
    lorem:
      type: boolean
    ipsum:
      type: string

  1. Any Of: Helps you to select from multiple properties where both can't be selected together at once.

Example workflows.yaml

The Example Workflow Explained

  1. Parameters Structure The parameters section includes age as an integer and items as an array. Each item in the array can contain either a foo or bar property, utilizing anyOf.

  2. Identification Methods The Workflow allows for two methods of identification using anyOf. Users can provide either:

  • A first name and last name (defaulting firstName to "Chuck"), or
  • An ID code.

  1. Required Fields The age field is required, while the fields under the two identification methods are optional but must comply with the anyOf logic.

  2. Display Step The steps section includes a debug:log action to display the collected information based on the provided input.

Example YAML
type: object
properties:
  age:
    type: integer
    title: Age
  items:
    type: array
    items:
      type: object
      anyOf:
      - properties:
          foo:
            type: string
      - properties:
          bar:
            type: string
anyOf:
- title: First method of identification
  properties:
    firstName:
      type: string
      title: First name
      default: Chuck
    lastName:
      type: string
      title: Last name
- title: Second method of identification
  properties:
    idCode:
      type: string
      title: ID code

For more such references and validate your conditional steps take a look at the react-json schema project.

Upload a file using Workflows​

Workflow supports a limited form of file types as input, in the sense that it will parse the file contents to Workflow inputs as data-urls.

There are 3 types of file upload.

  1. Single File: There are two formats available data-url and file.
  2. Multiple Files: Multiple files selectors are supported by defining an array of strings having data-url as a format.
  3. Single File with Accept Attribute: You can use the accept attribute to specify a filter for what file types the user can upload.
Example YAML
#Example
title: Files
type: object
properties:
  file:
    type: string
    format: data-url
    title: Single file
  files:
    type: array
    title: Multiple files
    items:
      type: string
      format: data-url
  filesAccept:
    type: string
    format: data-url
    title: Single File with Accept attribute
    ui:enableMarkdownInDescription: true
    ui:description: Provide the Json File
    ui:options:
      accept: .json

Using Secrets​

You may want to mark things as secret and make sure that these values are protected and not available through REST endpoints. You can do this by using the built-in ui:field: Secret and ui:widget: password.

info

ui:widget: password needs to be mentioned under the first page in-case you have multiple pages.

# example workflow.yaml
...
parameters:
  - title: <PAGE-1 TITLE>
    properties:
      property-1:
        title: title-1
        type: string
      property-2:
        title: title-2
    token:
      title: Harness Token
      type: string
      ui:widget: password
      ui:field: HarnessAuthToken
  - title: <PAGE-2 TITLE>
    properties:
      property-1:
        title: title-1
        type: string
      property-2:
        title: title-2
  - title: <PAGE-n TITLE>
...

You can define this property as any normal parameter, however the consumption of this parameter will not be available through ${{ parameters.myKey }} you will instead need to use ${{ secrets.myKey }} in your workflow.yaml.

Parameters will be automatically masked in the review step.

Example YAML
apiVersion: scaffolder.backstage.io/v1beta3
kind: Template
metadata:
  name: v1beta3-demo
  title: Test Action Workflow
  description: Workflows Demo
spec:
  owner: backstage/techdocs-core
  type: service

  parameters:
    - title: Authentication
      description: Provide authentication for the resource
      required:
        - username
        - password
      properties:
        username:
          type: string
          # use the built in Secret field extension
          ui:field: Secret
        password:
          type: string
          ui:field: Secret

  steps:
    - id: setupAuthentication
      action: auth:create
      input:
        # make sure to use ${{ secrets.parameterName }} to reference these values
        username: ${{ secrets.username }}
        password: ${{ secrets.password }}

Built in Filters​

Workflow filters are functions that help you transform data, extract specific information, and perform various operations in Workflows.

This section introduces the built-in filters provided by Backstage and offers examples of how to use them in the Workflows. It's important to mention that Backstage also leverages the native filters from the Nunjucks library. For a complete list of these native filters and their usage, refer to the Nunjucks documentation.

parseRepoUrl​

The parseRepoUrl filter parse a repository URL into its components, such as owner, repository name, and more.

Usage Example:

- id: log
  name: Parse Repo URL
  action: debug:log
  input:
    extra: ${{ parameters.repoUrl | parseRepoUrl }}
  • Input: github.com?repo=backstage&org=backstage
  • Output: RepoSpec

parseEntityRef​

The parseEntityRef filter allows you to extract different parts of an entity reference, such as the kind, namespace, and name.

Usage example

  1. Without context
- id: log
  name: Parse Entity Reference
  action: debug:log
  input:
    extra: ${{ parameters.owner | parseEntityRef }}
  1. With context
- id: log
  name: Parse Entity Reference
  action: debug:log
  input:
    extra: ${{ parameters.owner | parseEntityRef({ defaultKind:"group", defaultNamespace:"another-namespace" }) }}

pick​

This pick filter allows you to select specific properties from an object.

Usage Example

- id: log
  name: Pick
  action: debug:log
  input:
    extra: ${{ parameters.owner | parseEntityRef | pick('name') }}
  • Input: { kind: 'Group', namespace: 'default', name: 'techdocs' }
  • Output: techdocs

projectSlug​

The projectSlug filter generates a project slug from a repository URL

Usage Example

- id: log
  name: Project Slug
  action: debug:log
  input:
    extra: ${{ parameters.repoUrl | projectSlug }}
  • Input: github.com?repo=backstage&org=backstage
  • Output: backstage/backstage

Workflow UI Pickers​

Collecting input from the user is a very large part of the Workflows as a whole. Sometimes the built-in components and fields just aren't good enough, and sometimes you want to enrich the form that the users sees with better inputs that fit better.

This is where Workflow UI Pickers come in.

Harness Specific UI Pickers​

1. EntityFieldPicker​

info

Only string data type is supported for the EntityPicker.

The input props that can be specified under ui:options for the EntityFieldPicker field extension.

displayField​

This is used to fetch the value from catalog dynamically, corresponding to the key mentioned.

jiraprojectID:
    title: Jira Project Key
    type: string
    description: The key for your JIRA project
    ui:field: EntityFieldPicker
    ui:displayField: metadata.jiraProjectId
    ui:options:
    catalogFilter:
        kind:
        - Component
        - Service

In the above example it will fetch all the jiraProjectId for the software components kind mentioned under catalogFilter.

allowArbitraryValues​

Whether to allow arbitrary user input. Defaults to true.

allowArbitraryValues provides input validation when selecting an entity as the values you enter will correspond to a valid entity.

  • Adding a valid entity with allowArbitraryValues as false
entity:
  title: Entity
  type: string
  description: Entity of the component
  ui:field: EntityFieldPicker
  ui:options:
    allowArbitraryValues: false
  • Adding an arbitrary entity with allowArbitraryValues as true (default value)
entity:
  title: Entity
  type: string
  description: Entity of the component
  ui:field: EntityFieldPicker
  ui:options:
    allowArbitraryValues: true

catalogFilter​

catalogFilter supports filtering options by any field(s) of an entity.

  • Get all entities of kind Group
entity:
  title: Entity
  type: string
  description: Entity of the component
  ui:field: EntityFieldPicker
  ui:options:
    catalogFilter:
      - kind: Group
  • Get entities of kind Group and spec.type team
entity:
  title: Entity
  type: string
  description: Entity of the component
  ui:field: EntityFieldPicker
  ui:options:
    catalogFilter:
      - kind: Group
        spec.type: team

defaultKind​

The default entity kind.

system:
  title: System
  type: string
  description: System of the component
  ui:field: EntityFieldPicker
  ui:options:
    catalogFilter:
      kind: System
    defaultKind: System

defaultNamespace​

The ID of a namespace that the entity belongs to. The default value is default.

  • Listing all entities in the default namespace (default value)
entity:
  title: Entity
  type: string
  description: Entity of the component
  ui:field: EntityFieldPicker
  ui:options:
    defaultNamespace: default

2. HarnessOrgPicker​

Fetches all the org ID dynamically.

#Example
apiVersion: scaffolder.backstage.io/v1beta3
kind: Template
metadata:
  name: your-workflow
  ...
spec:
  ...
  parameters:
    - title: Details
       properties:
         projectId:
           title: Project Identifier
           description: Harness Project Identifier
           type: string
           ui:field: HarnessProjectPicker
         orgId:
            title: Org Identifier
            type: string
            ui:field: HarnessOrgPicker
    ...

3. HarnessProjectPicker​

Fetches all the project ID dynamically.

# Example workflow.yaml file
apiVersion: scaffolder.backstage.io/v1beta3
kind: Template
metadata:
  name: your-workflow
  ...
spec:
  ...
  parameters:
    - title: Details
       properties:
         projectId:
           title: Project Identifier
           description: Harness Project Identifier
           type: string
           ui:field: HarnessProjectPicker

4. HarnessAutoOrgPicker​

It autopopulates org ID on project selection. So now when you select a project ID as an input the org ID gets selected automatically if required as an input.

  1. For HarnessAutoOrgPicker to work, it is suggested to name the Project Identifier under Properties as projectId and using the HarnessProjectPicker.
# Example workflow.yaml file
apiVersion: scaffolder.backstage.io/v1beta3
kind: Template
metadata:
  name: your-workflow
  ...
spec:
  ...
  parameters:
    - title: Details
       properties:
         projectId:
           title: Project Identifier
           description: Harness Project Identifier
           type: string
           ui:field: HarnessProjectPicker
         orgId:
           title: Org Identifier
           description: Harness org Identifier
           type: string
           ui:field: HarnessAutoOrgPicker

  1. In case the properties Project Identifier is named something else other than projectId in that case for the Workflow action to function as desired we need to add it as a dependency under projectPickerRef
# Example workflow.yaml file
properties:
    <ANY NAME OTHER THAN projectId>:
        title: Project Identifier
        description: Harness Project Identifier
        type: string
        ui:field: HarnessProjectPicker
    orgId:
        title: Org Identifier
        description: Harness org Identifier
        type: string
        ui:field: HarnessAutoOrgPicker
        dependencies:
          projectPickerRef:
            - 'project_name'

Other UI Pickers​

1. OwnerPicker​

OwnerPicker is used for developers to pick a User Group from the list of Groups that exist in the account.

allowArbitraryValues​

Whether to allow arbitrary user input. Defaults to true.

allowArbitraryValues provides input validation when selecting an owner as the values you enter will correspond to a valid owner.

  • Adding a valid owner with allowArbitraryValues as false
owner:
  title: Owner
  type: string
  description: Owner of the component
  ui:field: OwnerPicker
  ui:options:
    allowArbitraryValues: false
  • Adding an arbitrary owner with allowArbitraryValues as true (default value)
owner:
  title: Owner
  type: string
  description: Owner of the component
  ui:field: OwnerPicker
  ui:options:
    allowArbitraryValues: true

catalogFilter​

catalogFilter supports filtering options by any field(s) of an entity.

  • Get all entities of kind Group
owner:
  title: Owner
  type: string
  description: Owner of the component
  ui:field: OwnerPicker
  ui:options:
    catalogFilter:
      - kind: Group
  • Get entities of kind Group and spec.type team
owner:
  title: Owner
  type: string
  description: Owner of the component
  ui:field: OwnerPicker
  ui:options:
    catalogFilter:
      - kind: Group
        spec.type: team

defaultNamespace​

The ID of a namespace that the owner belongs to. The default value is default.

  • Listing owners in the default namespace (default value)
owner:
  title: Owner
  type: string
  description: Owner of the component
  ui:field: OwnerPicker
  ui:options:
    catalogFilter:
      - kind: Group
    defaultNamespace: default
  • Listing owners in the payment namespace
owner:
  title: Owner
  type: string
  description: Owner of the component
  ui:field: OwnerPicker
  ui:options:
    catalogFilter:
      - kind: Group
    defaultNamespace: payment

2. EntityPicker​

info

Only string data type is supported for the EntityPicker.

The input props that can be specified under ui:options for the EntityPicker field extension.

allowArbitraryValues​

Whether to allow arbitrary user input. Defaults to true.

allowArbitraryValues provides input validation when selecting an entity as the values you enter will correspond to a valid entity.

  • Adding a valid entity with allowArbitraryValues as false
entity:
  title: Entity
  type: string
  description: Entity of the component
  ui:field: EntityPicker
  ui:options:
    allowArbitraryValues: false
  • Adding an arbitrary entity with allowArbitraryValues as true (default value)
entity:
  title: Entity
  type: string
  description: Entity of the component
  ui:field: EntityPicker
  ui:options:
    allowArbitraryValues: true

catalogFilter​

catalogFilter supports filtering options by any field(s) of an entity.

  • Get all entities of kind Group
entity:
  title: Entity
  type: string
  description: Entity of the component
  ui:field: EntityPicker
  ui:options:
    catalogFilter:
      - kind: Group
  • Get entities of kind Group and spec.type team
entity:
  title: Entity
  type: string
  description: Entity of the component
  ui:field: EntityPicker
  ui:options:
    catalogFilter:
      - kind: Group
        spec.type: team

defaultKind​

The default entity kind.

system:
  title: System
  type: string
  description: System of the component
  ui:field: EntityPicker
  ui:options:
    catalogFilter:
      kind: System
    defaultKind: System

defaultNamespace​

The ID of a namespace that the entity belongs to. The default value is default.

  • Listing all entities in the default namespace (default value)
entity:
  title: Entity
  type: string
  description: Entity of the component
  ui:field: EntityPicker
  ui:options:
    defaultNamespace: default

3. MultiEntityPicker​

The input props that can be specified under ui:options for the MultiEntityPicker field extension.

allowArbitraryValues​

Whether to allow arbitrary user input. Defaults to true.

allowArbitraryValues provides input validation when selecting an entity as the values you enter will correspond to a valid entity.

  • Adding a valid entity with allowArbitraryValues as false
entity:
  title: Entities
  type: array
  description: Entities of the component
  ui:field: MultiEntityPicker
  ui:options:
    allowArbitraryValues: false
  • Adding an arbitrary entity with allowArbitraryValues as true (default value)
entity:
  title: Entities
  type: array
  description: Entities of the component
  ui:field: MultiEntityPicker
  ui:options:
    allowArbitraryValues: true

catalogFilter​

catalogFilter supports filtering options by any field(s) of an entity.

  • Get all entities of kind Group
entity:
  title: Entities
  type: array
  description: Entities of the component
  ui:field: MultiEntityPicker
  ui:options:
    catalogFilter:
      - kind: Group
  • Get entities of kind Group and spec.type team
entity:
  title: Entities
  type: array
  description: Entities of the component
  ui:field: MultiEntityPicker
  ui:options:
    catalogFilter:
      - kind: Group
        spec.type: team

defaultKind​

The default entity kind.

system:
  title: System
  type: array
  description: Systems of the component
  ui:field: MultiEntityPicker
  ui:options:
    catalogFilter:
      kind: System
    defaultKind: System

defaultNamespace​

The ID of a namespace that the entity belongs to. The default value is default.

  • Listing all entities in the default namespace (default value)
entity:
  title: Entity
  type: array
  description: Entities of the component
  ui:field: MultiEntityPicker
  ui:options:
    defaultNamespace: default
  • Listing all entities in the payment namespace
entity:
  title: Entity
  type: array
  description: Entities of the component
  ui:field: MultiEntityPicker
  ui:options:
    defaultNamespace: payment

The Repository Picker​

In order to make working with repository providers easier, we've built a custom picker that can be used by overriding the ui:field option in the uiSchema for a string field. Instead of displaying a text input block it will render our custom component that we've built which makes it easy to select a repository provider, and insert a project or owner, and repository name.

You can see it in the above full example which is a separate step and it looks a little like this:

- title: Choose a location
  required:
    - repoUrl
  properties:
    repoUrl:
      title: Repository Location
      type: string
      ui:field: RepoUrlPicker
      ui:options:
        allowedHosts:
          - github.com

The allowedHosts part should be set to where you wish to enable this Workflow to publish to. And it can be any host that is listed in your integrations config in app-config.yaml.

Besides specifying allowedHosts you can also restrict the Workflow to publish to repositories owned by specific users/groups/namespaces by setting the allowedOwners option. With the allowedRepos option you are able to narrow it down further to a specific set of repository names. A full example could look like this:

- title: Choose a location
  required:
    - repoUrl
  properties:
    repoUrl:
      title: Repository Location
      type: string
      ui:field: RepoUrlPicker
      ui:options:
        allowedHosts:
          - github.com
        allowedOwners:
          - backstage
          - someGithubUser
        allowedRepos:
          - backstage

For a list of all possible ui:options input props for RepoUrlPicker, please visit here.

Using the Users oauth token​

There's a little extra magic that you get out of the box when using the RepoUrlPicker as a field input. You can provide some additional options under ui:options to allow the RepoUrlPicker to grab a oauth token for the user for the required repository.

This is great for when you are wanting to create a new repository, or wanting to perform operations on top of an existing repository.

A sample Workflow that takes advantage of this is like so:

Example YAML
apiVersion: scaffolder.backstage.io/v1beta3
kind: Template
metadata:
  name: v1beta3-demo
  title: Test Action Workflow
  description: Workflows Demo
spec:
  owner: backstage/techdocs-core
  type: service

  parameters:
    ...

    - title: Choose a location
      required:
        - repoUrl
      properties:
        repoUrl:
          title: Repository Location
          type: string
          ui:field: RepoUrlPicker
          ui:options:
            # Here's the option you can pass to the RepoUrlPicker
            requestUserCredentials:
              secretsKey: USER_OAUTH_TOKEN
              additionalScopes:
                github:
                  - workflow
            allowedHosts:
              - github.com
    ...

  steps:
    ...

    - id: publish
      name: Publish
      action: publish:github
      input:
        allowedHosts: ['github.com']
        description: This is ${{ parameters.name }}
        repoUrl: ${{ parameters.repoUrl }}
        # here's where the secret can be used
        token: ${{ secrets.USER_OAUTH_TOKEN }}

    ...

You will see from above that there is an additional requestUserCredentials object that is passed to the RepoUrlPicker. This object defines what the returned secret should be stored as when accessing using ${{ secrets.secretName }}, in this case it is USER_OAUTH_TOKEN. And then you will see that there is an additional input field into the publish:github action called token, in which you can use the secret like so: token: ${{ secrets.USER_OAUTH_TOKEN }}.

There's also the ability to pass additional scopes when requesting the oauth token from the user, which you can do on a per-provider basis, in case your Workflow can be published to multiple providers.

Note, that you will need to configure a connector for your source code management (SCM) service to make this feature work.

Pre-fill workflows with URL Params​

We can now automatically load IDP Workflow forms pre-filled using the formData URL query parameter. e.g.: https://app.harness.io/ng/account/account_id/module/idp/create/templates/default/a-python-lambda?formData=%7B%22project_name%22%3A%22auto%20filled%22%7D

The query parameters ?formData=%7B%22project_name%22%3A%22auto%20filled%22%7 in the end of the URL allow you to automatically fill in values of the form. Please see the below table for explanation of individual tokens in the query param.

ItemExample ValueExplanation
formDataformDataKey of the query param.formData object is used to fill out IDP Workflow forms.
{"key"%3A"value"}{"title"%3A"Title from query params"}Value of the query param. A JSON object with invalid URL characters encoded.: encodes to %3A

Add Read only Fields​

Using automatically filled out values is handy when wanting to direct users to use IDP Workflows with known good values. This also allows automation to be constructed around the Workflows, where the automation can provide fully constructed IDP URLs to the user. You can also prevent user from modifying the form values inserted from query params by making the form fields readonly. See below example of a minimal form which would be filled using query params defined in the above explanation.

Example YAML
## Example Workflow
apiVersion: scaffolder.backstage.io/v1beta3
kind: Template
metadata:
  name: test-workflow-pipeline
  title: Test pipeline using Workflows
spec:
  owner: name.owner
  type: service
  parameters:
    - title: Repository Name
      properties:
        project_name:
          title: Name your project
          ui:readonly: true
          type: string
        token:
          title: Harness Token
          type: string
          ui:widget: password
          ui:field: HarnessAuthToken
  steps:
    - id: trigger
      name: Creating your github repository
      action: trigger:harness-custom-pipeline
      input:
        url: PIPELINE_URL
        inputset:
          github_org: ${{ parameters.project_name }}
        apikey: ${{ parameters.token }}
  output:
    links:
      - title: Pipeline Details
        url: ${{ steps.trigger.output.PipelineUrl }}

For Use-Cases you don't find here​

It is suggested to use the react-jsonschema-form playground to build the frontend(UI for Inputs) for use-cases that are not listed here. Nunjucks is templating engine for the Self Service Workflows.