From a7f0e1994a88375b01d84e63b2ce2098c14d0761 Mon Sep 17 00:00:00 2001
From: blam <ben@blam.sh>
Date: Thu, 15 Jul 2021 13:09:25 +0200
Subject: [PATCH] docs: document the cookiecutter actions

Signed-off-by: blam <ben@blam.sh>
---
 .../README.md                                 | 160 +++++++++++++++++-
 1 file changed, 156 insertions(+), 4 deletions(-)

diff --git a/plugins/scaffolder-backend-module-cookiecutter/README.md b/plugins/scaffolder-backend-module-cookiecutter/README.md
index a76d8076e4..b97b1bbb05 100644
--- a/plugins/scaffolder-backend-module-cookiecutter/README.md
+++ b/plugins/scaffolder-backend-module-cookiecutter/README.md
@@ -1,9 +1,161 @@
 # scaffolder-backend-module-cookiecutter
 
-Welcome to the scaffolder-backend-module-cookiecutter backend plugin!
-
-_This plugin was created through the Backstage CLI_
+Welcome to the `fetch:cookiecutter` action for the `scaffolder-backend`.
 
 ## Getting started
 
-<!-- TODO -->
+You need to configure the action in your backend:
+
+## From your Backstage root directory
+
+```
+cd packages/backend
+yarn add @backstage/plugin-scaffolder-backend-module-cookiecutter
+```
+
+Configure the action (you can check
+the [docs](https://backstage.io/docs/features/software-templates/writing-custom-actions#registering-custom-actions) to
+see all options):
+
+```typescript
+const actions = [
+  createFetchCookiecutterAction({
+    integrations,
+    reader,
+    containerRunner,
+  }),
+  ...createBuiltInActions({
+    ...
+  })
+];
+
+return await createRouter({
+  containerRunner,
+  logger,
+  config,
+  database,
+  catalogClient,
+  reader,
+  actions,
+});
+```
+
+After that you can use the action in your template:
+
+```yaml
+apiVersion: backstage.io/v1beta2
+kind: Template
+metadata:
+  name: cookiecutter-demo
+  title: Cookiecutter Test
+  description: Cookiecutter example
+spec:
+  owner: backstage/techdocs-core
+  type: service
+
+  parameters:
+    - title: Fill in some steps
+      required:
+        - name
+        - owner
+      properties:
+        name:
+          title: Name
+          type: string
+          description: Unique name of the component
+          ui:autofocus: true
+          ui:options:
+            rows: 5
+        owner:
+          title: Owner
+          type: string
+          description: Owner of the component
+          ui:field: OwnerPicker
+          ui:options:
+            allowedKinds:
+              - Group
+        system:
+          title: System
+          type: string
+          description: System of the component
+          ui:field: EntityPicker
+          ui:options:
+            allowedKinds:
+              - System
+            defaultKind: System
+
+    - title: Choose a location
+      required:
+        - repoUrl
+        - dryRun
+      properties:
+        repoUrl:
+          title: Repository Location
+          type: string
+          ui:field: RepoUrlPicker
+          ui:options:
+            allowedHosts:
+              - github.com
+        dryRun:
+          title: Only perform a dry run, don't publish anything
+          type: boolean
+          default: false
+
+  steps:
+    - id: fetch-base
+      name: Fetch Base
+      action: fetch:cookiecutter
+      input:
+        url: ./template
+        values:
+          name: '{{ parameters.name }}'
+          owner: '{{ parameters.owner }}'
+          system: '{{ parameters.system }}'
+          destination: '{{ parseRepoUrl parameters.repoUrl }}'
+
+    - id: publish
+      if: '{{ not parameters.dryRun }}'
+      name: Publish
+      action: publish:github
+      input:
+        allowedHosts: ['github.com']
+        description: 'This is {{ parameters.name }}'
+        repoUrl: '{{ parameters.repoUrl }}'
+
+    - id: register
+      if: '{{ not parameters.dryRun }}'
+      name: Register
+      action: catalog:register
+      input:
+        repoContentsUrl: '{{ steps.publish.output.repoContentsUrl }}'
+        catalogInfoPath: '/catalog-info.yaml'
+
+    - name: Results
+      if: '{{ parameters.dryRun }}'
+      action: debug:log
+      input:
+        listWorkspace: true
+
+  output:
+    links:
+      - title: Repository
+        url: '{{ steps.publish.output.remoteUrl }}'
+      - title: Open in catalog
+        icon: 'catalog'
+        entityRef: '{{ steps.register.output.entityRef }}'
+```
+
+You can also visit the `/create/actions` route in your Backstage application to find out more about the parameters this action accepts when it's installed to configure how you like.
+
+### Environment setup
+
+The environment needs to have either `cookiecutter` installed and be available in the `PATH` or access to a `docker` daemon so it can spin up a docker container with `cookiecutter` available.
+
+If you are running Backstage from a Docker container and you want to avoid calling a container inside a container, you can set up `cookiecutter` in your own image, this will use the local installation instead.
+
+You can do so by including the following lines in the last step of your Dockerfile:
+
+```dockerfile
+RUN apt-get update && apt-get install -y python3 python3-pip
+RUN pip3 install cookiecutter
+```