Configuring a template¶

Configuration sources¶

It is important that you understand how Copier works. It has 2 kinds of configurations:

Settings for Copier itself. This includes things as minimal copier version required, which subdirectory to render, tasks to run, etc.
Answers. This is customized per template. The user answers template questions, and those answers are stored as variables available for the template at rendering time.

Copier reads settings from these sources, in this order of priority:

Command line or API arguments.
The copier.yml file. Settings here always start with an underscore (e.g. _min_copier_version).

Copier obtains answers from these sources, in this order of priority:

Command line or API arguments.
Asking the user. Notice that Copier will not ask any questions answered in the previous source.
The last answers file.
The copier.yml file, where default values are defined.

The `copier.yml` file¶

The copier.yml (or copier.yaml) file is found in the root of the template, and it is the main entrypoint for managing your template configuration. It will be read and used for two purposes:

Prompting the user for information.
Applying template settings (excluding files, setting arguments defaults, etc.).

Questions¶

For each key found, Copier will prompt the user to fill or confirm the values before they become available to the project template. For example, this:

name_of_the_project: My awesome project
number_of_eels: 1234
your_email: ""

Will result in these questions:

  name_of_the_project? Format: yaml
🎤 [My awesome project]:

  number_of_eels? Format: yaml
🎤 [1234]:

  your_email? Format: yaml
🎤 []:

Advanced prompt formatting¶

Apart from the simplified format, as seen above, Copier supports a more advanced format to ask users for data. To use it, the value must be a dict.

Supported keys:

type: User input must match this type. Options are: bool, float, int, json, str, yaml (default).
help: Additional text to help the user know what's this question for.
choices: To restrict possible values.
default: Leave empty to force the user to answer. Provide a default to save him from typing it if it's quite common. When using choices, the default must be the choice value, not its key. If values are quite long, you can use YAML anchors.

love_copier:
  type: bool # This makes Copier ask for y/n
  help: Do you love Copier?
  default: yes # Without a default, you force the user to answer

project_name:
  type: str # Any value will be treated raw as a string
  help: An awesome project needs an awesome name. Tell me yours.
  default: paradox-specifier

rocket_launch_password:
  type: str
  secret: true # This value will not be logged into .copier-answers.yml
  default: my top secret password

# I'll avoid default and help here, but you can use them too
age:
  type: int

height:
  type: float

any_json:
  help: Tell me anything, but format it as a one-line JSON string
  type: json

any_yaml:
  help: Tell me anything, but format it as a one-line YAML string
  type: yaml # This is the default type, also for short syntax questions

your_favorite_book:
  # User will type 1 or 2, but your template will get the value
  choices:
    - The Bible
    - The Hitchhiker's Guide to the Galaxy

project_license:
  # User will type 1 or 2 and will see only the dict key, but you will
  # get the dict value in your template
  choices:
    MIT: &mit_text |
      Here I can write the full text of the MIT license.
      This will be a long text, shortened here for example purposes.
    Apache2: |
      Full text of Apache2 license.
  # When using choices, the default value is the value, **not** the key;
  # that's why I'm using the YAML anchor declared above to avoid retyping the
  # whole license
  default: *mit_text
  # You can still define the type, to make sure answers that come from --data
  # CLI argument match the type that your template expects
  type: str

close_to_work:
  help: Do you live close to your work?
  # This format works just like the dict one
  choices:
    - [at home, I work at home]
    - [less than 10km, quite close]
    - [more than 10km, not so close]
    - [more than 100km, quite far away]

Prompt templating¶

Values of prompted keys can use Jinja templates.

Keep in mind that the configuration is loaded as YAML, so the contents must be valid YAML and respect Copier's structure. That is why we explicitly wrap some strings in double-quotes in the following examples.

Answers provided through interactive prompting will not be rendered with Jinja, so you cannot use Jinja templating in your answers.

# default
username:
  type: str

organization:
  type: str

email:
  type: str
  # Notice that both `username` and `organization` have been already asked
  default: "[[ username ]]@[[ organization ]].com"

# help
copyright_holder:
  type: str
  help: The person or entity within [[ organization ]] that holds copyrights.

# type
target:
  type: str
  choices:
    - humans
    - machines

user_config:
  type: "[% if target == 'humans' %]yaml[% else %]json[% endif %]"

# choices
title:
  type: str
  help: Your title within [[ organization ]]

contact:
  choices:
    Copyright holder: "[[ copyright_holder ]]"
    CEO: Alice Bob
    CTO: Carl Dave
    "[[ title ]]": "[[ username ]]"

Include other YAML files¶

To reuse configurations across templates you can reference other yaml files. You just need to state the !include together with the absolute or relative path to the file to be included. Multiple files can be included per copier.yml. For more detailed instructions, see pyyaml-include.

Example:

# other_place/include_me.yml
common_setting: "1"

# copier.yml
!include other_place/include_me.yml

Warning: You can't have in the same file a top !include tag and classic YAML syntax, see this pyyaml-include issue.

# Invalid file
!include other_place/include_me.yml
foo: "bar"

Available settings¶

Template settings alter how the template is rendered. They come from several sources.

Remember that the key must be prefixed with an underscore if you use it in the copier.yml file.

`answers_file`¶

Format: str
CLI flags: -a, --answers-file
Default value: .copier-answers.yml

File where answers will be recorded by default. Remember to add that file to your Git template if you want to support updates.

Don't forget to read the docs about the answers file.

Example copier.yml:

_answers_file: .my-custom-answers.yml

`data`¶

Format: dict|List[str=str]
CLI flags: -d, --data
Default value: N/A

Give answers to questions through CLI/API.

This cannot be defined in copier.yml, where its equivalent would be just normal questions with default answers.

Example CLI usage to take all default answers from template, except the user name, which is overriden, and don't ask user anything else:

copier -fd 'user_name=Manuel Calavera' copy template destination

`exclude`¶

Format: List[str]
CLI flags: -x, --exclude
Default value: ["copier.yaml", "copier.yml", "~*", "*.py[co]", "__pycache__", ".git", ".DS_Store", ".svn"]

Patterns for files/folders that must not be copied.

The CLI option can be passed several times to add several patterns.

Example copier.yml:

_exclude:
  - "*.bar"
  - ".git"

Example CLI usage to copy only a single file from the template:

copier --exclude '*' --exclude '!file-i-want' copy template destination

`extra_paths`¶

Format: List[str]
CLI flags: -p, --extra-paths
Default value: N/A

Additional paths from where to search for templates.

Example copier.yml:

_extra_paths:
  - ~/Projects/templates

`force`¶

Format: bool
CLI flags: -q, --force
Default value: False

Overwrite files that already exist, without asking.

Also don't ask questions to the user; just use default values obtained from other sources.

It makes no sense to define this in copier.yml.

`migrations`¶

Format: List[dict]
CLI flags: N/A
Default value: N/A

Migrations are like tasks, but each item in the list is a dict with these keys:

version: Indicates the version that the template update has to go through to trigger this migration. It is evaluated using PEP 440.
before (optional): Commands to execute before performing the update. The answers file is reloaded after running migrations in this stage, to let you migrate answer values.
after (optional): Commands to execute after performing the update.

Migrations will run in the same order as declared here (so you could even run a migration for a higher version before running a migration for a lower version if the higher one is declared before and the update passes through both).

They will only run when new version >= declared version > old version. And only when updating (not when copying for the 1st time).

If the migrations definition contains Jinja code, it will be rendered with the same context as the rest of the template.

Migration processes will contain the $VERSION_FROM, $VERSION_TO, $VERSION_CURRENT and $STAGE (before/after) environment variables

Example copier.yml:

_migrations:
  - version: v1.0.0
    before:
      - rm ./old-folder
    after:
      # [[ _copier_conf.src_path ]] points to the path where the template was
      # cloned, so it can be helpful to run migration scripts stored there.
      - invoke -r [[ _copier_conf.src_path ]] -c migrations migrate $VERSION_CURRENT

`min_copier_version`¶

Format: str
CLI flags: N/A
Default value: N/A

Specifies the minimum required version of Copier to generate a project from this template. The version must be follow the PEP 440 syntax. Upon generating or updating a project, if the installed version of Copier is less than the required one, the generation will be aborted and an error will be shown to the user.

Example copier.yml:

_min_copier_version: "4.1.0"

`pretend`¶

Format: bool
CLI flags: -q, --pretend
Default value: False

Run but do not make any changes.

It makes no sense to define this in copier.yml.

`quiet`¶

Format: bool
CLI flags: -q, --quiet
Default value: False

Suppress status output.

It makes no sense to define this in copier.yml.

`skip_if_exists`¶

Format: List[str]
CLI flags: -s, --skip
Default value: N/A

Patterns for files/folders that must be skipped if they already exist.

For example, it can be used if your project generates a password the 1st time and you don't want to override it next times:

# copier.yml
_skip_if_exists: .secret_password.yml

# .secret_password.yml.tmpl
[[make_secret()|tojson]]

`subdirectory`¶

Format: str
CLI flags: -b, --subdirectory
Default value: N/A

Subdirectory to use as the template root when generating a project. If not specified, the root of the template is used.

Example copier.yml:

_subdirectory: src

Example CLI usage to choose a different subdirectory template:

copier --subdirectory template2 -b copy template destination

`tasks`¶

Format: List[str|List[str]]
CLI flags: N/A
Default value: N/A

Commands to execute after generating or updating a project from your template.

They run ordered, and with the $STAGE=task variable in their environment.

Can be overridden with the tasks API option, but not from CLI.

Example copier.yml:

_tasks:
  # Strings get executed under system's default shell
  - "git init"
  - "rm [[ name_of_the_project ]]/README.md"
  # Arrays are executed without shell, saving you the work of escaping arguments
  - [invoke, "--search-root=[[ _copier_conf.src_path ]]", after-copy]
  # You are able to output the full conf to JSON, to be parsed by your script,
  # but you cannot use the normal `|tojson` filter; instead, use `.json()`
  - [invoke, end-process, "--full-conf=[[ _copier_conf.json() ]]"]

`templates_suffix`¶

Format: str
CLI flags: N/A
Default value: .tmpl

Suffix that instructs which files are to be processed by Jinja as templates.

Example copier.yml:

_templates_suffix: .jinja

`vcs_ref`¶

Format: str
CLI flags: -r, -vcs-ref
Default value: N/A (use latest release)

When copying or updating from a git-versioned template, indicate which template version to copy.

This is stored automatically in the answers file, like this:

_vcs_ref: v1.0.0

It makes no sense to define this in copier.yml.

By default, copier will copy from the last release found in template git tags, sorted as PEP 440.

Patterns syntax¶

Copier supports matching names against patterns in a gitignore style fashion. This works for the options exclude and skip. This means you can write patterns as you would for any .gitignore file. The full range of the gitignore syntax ist supported via pathspec.

For example, with the following settings in your copier.yml file would exclude all files ending with txt from being copied to the destination folder, except the file a.txt.

_exclude:
  # match all text files...
  - "*.txt"
  # .. but not this one:
  - "!a.txt"

The `.copier-answers.yml` file¶

If the destination path exists and a .copier-answers.yml file is present there, it will be used to load the last user's answers to the questions made in the copier.yml file.

This makes projects easier to update because when the user is asked, the default answers will be the last ones he used.

To make sure projects based on your templates can make use of this nice feature, add a file called [[ _copier_conf.answers_file ]].tmpl (or your chosen suffix) in your template's root folder, with this content:

# Changes here will be overwritten by Copier
[[_copier_answers|to_nice_yaml]]

Warning: If this file is not called exactly [[ _copier_conf.answers_file ]].tmpl your users will not be able to choose a custom answers file name, and thus they will not be able to integrate several updatable templates into one destination directory.

The builtin _copier_answers variable includes all data needed to smooth future updates of this project. This includes (but is not limited to) all JSON-serializable values declared as user questions in the copier.yml file.

As you can see, you also have the power to customize what will be logged here. Keys that start with an underscore (_) are specific to Copier. Other keys should match questions in copier.yml.

If you plan to integrate several templates into one single downstream project, you can define a different default path for this file.

Configuring a template¶

Configuration sources¶

The copier.yml file¶

Questions¶

Advanced prompt formatting¶

Prompt templating¶

Include other YAML files¶

Available settings¶

answers_file¶

data¶

exclude¶

extra_paths¶

force¶

migrations¶

min_copier_version¶

pretend¶

quiet¶

skip_if_exists¶

subdirectory¶

tasks¶

templates_suffix¶

vcs_ref¶

Patterns syntax¶

The .copier-answers.yml file¶

The `copier.yml` file¶

`answers_file`¶

`data`¶

`exclude`¶

`extra_paths`¶

`force`¶

`migrations`¶

`min_copier_version`¶

`pretend`¶

`quiet`¶

`skip_if_exists`¶

`subdirectory`¶

`tasks`¶

`templates_suffix`¶

`vcs_ref`¶

The `.copier-answers.yml` file¶