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Adding your own Templates

Templates are stored in the Software Catalog under a kind Template. The minimum that is needed to define a template is a template.yaml file, but it would be good to also have some files in there that can be templated in.

A simple template.yaml definition might look something like this:

apiVersion: backstage.io/v1beta2
kind: Template
# some metadata about the template itself
metadata:
  name: v1beta2-demo
  title: Test Action template
  description: scaffolder v1beta2 template demo
spec:
  owner: backstage/techdocs-core
  type: service

  # these are the steps which are rendered in the frontend with the form input
  parameters:
    - title: Fill in some steps
      required:
        - name
      properties:
        name:
          title: Name
          type: string
          description: Unique name of the component
          ui:autofocus: true
          ui:options:
            rows: 5
    - title: Choose a location
      required:
        - repoUrl
      properties:
        repoUrl:
          title: Repository Location
          type: string
          ui:field: RepoUrlPicker
          ui:options:
            allowedHosts:
              - github.com

  # here's the steps that are executed in series in the scaffolder backend
  steps:
    - id: fetch-base
      name: Fetch Base
      action: fetch:cookiecutter
      input:
        url: ./template
        values:
          name: '{{ parameters.name }}'

    - id: fetch-docs
      name: Fetch Docs
      action: fetch:plain
      input:
        targetPath: ./community
        url: https://github.com/backstage/community/tree/main/backstage-community-sessions

    - id: publish
      name: Publish
      action: publish:github
      input:
        allowedHosts: ['github.com']
        description: 'This is {{ parameters.name }}'
        repoUrl: '{{ parameters.repoUrl }}'

    - id: register
      name: Register
      action: catalog:register
      input:
        repoContentsUrl: '{{ steps.publish.output.repoContentsUrl }}'
        catalogInfoPath: '/catalog-info.yaml'

Template Entity contains more information about the required fields.

Once we have a template.yaml ready, we can then add it to the service catalog for use by the scaffolder.

You can add the template files to the catalog through static location configuration, for example:

catalog:
  locations:
    - type: url
      target: https://github.com/spotify/cookiecutter-golang/blob/master/template.yaml
      rules:
        - allow: [Template]

Or you can add the template using the catalog-import plugin, which unless configured differently should be running on /catalog-import.

For information about writing your own templates, you can check out the docs here