Question: how to programmatically bootstrap a cookiecutter

• Cookiecutter version: cookiecutter==1.7.2 (current stable)
• Python version: Python==3.8.6

Description:

I am spooling up a cookiecutter repository called my-cookiecutter (not the real name), and have it checked out locally.

cookiecutter.json

{
    "foo": "",
}

I have another repo called instance-01 (not the real name) where I want to have pre-supplied parameters for cookiecutter.json in a file.

instance-01-cookiecutter-config.json

{
    "foo": "bar",
}

I would like to run cookiecutter ../path/to/my-cookiecutter and somehow take in the instance-01-cookiecutter-config.json (instead of having to manually fill out prompts).

I have read through most of the cookiecutter docs and many issues, and can’t figure out if this is something cookiecutter can do.

In other words, how can I programmatically bootstrap a cookiecutter? Is it possible?

[edesz]

Hi @jamesbraza, unless I’m misunderstanding the issue, this is exactly what cookiecutter’s --config-file (docs) command line argument is designed to address. This is a YAML file that accepts a default-context block consisting of the template parameter’s name-value pairs (specified in cookiecutter.json) that will be injected as default values when you generate a templated project with cookiecutter. This partly supports an input-less workflow. So, for example if you had {"foo": ""} in your cookiecutter.json, then you could specify {"foo": "bar"} as one of the name-value pairs in the default-context block of a configuration file.

With this, the template’s default values from this config file are set to be used when rendering the template. If you now run cookiecutter --config-file <your-config-file>.yaml, cookiecutter will still prompt for input, but now the values from <your-config-file>.yaml will be injected as the default values at the corresponding prompts. With this setup, you could use cookiecutter in two ways

1. If you generate your cookiecutter template as usual with

   $ cookiecutter
   

   then you would get

   foo []:
   

   as the prompt for foo but you have to manually enter a value before you can press Enter.
2. On the other hand, if you generate the template with

   $ cookiecutter --config-file <your-config-file>.yaml
   

   then you would get

   for [bar]:
   

   as the prompt for foo. Now, you can simply press Enter without needing to supply any value because the value for foo will be automatically set to bar (which comes from <your-config-file>.yaml).

So, what’s left to do now, is to inform cookiecutter to actually skip all prompts. To avoid any user input, the CLI argument --no-input (docs) is required. This skips any prompts and uses the values from cookiecutter.json. However, since a custom configuration file is also being specified, those config file settings are treated like the defaults in cookiecutter.json and so those parameters are used in the template.

To summarize all this, here’s a simple example of the overall workflow

1. Set up /home/<username>/my-cookiecutter/cookiecutter.json

   {
       "foo": ""
   }
   

2. Set up the config file, at /home/<username>/my-cookiecutter/config.yaml, which will allow you to automatically specify a value for foo when generating a template

   default_context:
       foo: "bar"
   

3. Use the template to render a project with no user inputs from the CLI

   $ cookiecutter my-cookiecutter \
          --no-input \
          --config-file /home/<username>/my-cookiecutter/config.yaml
   

   and your project is rendered from the template with no prompts.

Notes

1. Values in the default_context block of the user config file are injected into all cookiecutter projects. So, after generating your first project template (but before you generate your second project template), you would need to replace these config file values with a new set of defaults that are specific to the second template to be rendered.

Hope this helps with your question.

Additional Links

1. Relevant stackoverflow question

[tpoindessous]

I was looking at last commits and I saw this one :

https://github.com/cookiecutter/cookiecutter/commit/d74b085260248f5ab180f9e582ea973108fa3e2b

Cookiecutter authors added a new option for selecting replay file.

This is not exactly what we want 😃 but it can be an alternative or the beginning of a new option 😃