Safely creating releases when you change the version number.

The intention is to only create the release tag when the release is good to go. No more brown bag releases, where a tag is cut only to find there's a continuous integration or build failure that means you immediately need to cut another tag.

You use it by adding configuration to a yaml or toml file, and then adding the following to your continuous integration pipeline:

pip install -U carthorse
carthorse

• Extract your project's version from its source code.
• Format a tag based on the version.
• Perform a number of checks, if any of those fail, stop.
• Perform any actions you specify, which usually includes creating and pushing the version tag.

Your file should contain a section such as the following:

[tool.carthorse]
version-from = "poetry"
tag-format = "v{version}"
when = [
  "version-not-tagged"
]
actions = [
   { run="poetry publish --build"},
   { name="create-tag"},
]

This is designed so that it can be included as part of a pyproject.toml file.

Your file should contain a section such as the following:

carthorse:
  version-from: poetry
  tag-format: v{version}
  when:
    - version-not-tagged
  actions:
    - run: "poetry publish --build"
    - create-tag

The following methods of extracting the version of a project are currently supported:

pyproject.toml

This will parse a project's pyproject.toml and use the standard version key as the version for the project.

setup.py

This will run python setup.py --version and use the version returned.

poetry

This will parse a project's pyproject.toml and use the tool.poetry.version key as the version for the project.

flit

This will extract the version from a flit-style __version__ without importing the package. For example, if your module is called foobar, this will look in either foobar/__init__.py or foobar.py. The config for that would be:

[tool.carthorse]
version-from = { name="flit", module="foobar" }

file

This will extract the version from a specified file. By default, this will be the stripped contents of the whole file, but a pattern can be specified. This can be useful to extract the version from a setup.py without executing it. The config for that would be:

[tool.carthorse]
version-from = { name="file", path="setup.py", pattern="version=['\"](?P<version>[^'\"]+)" }

This extracts only the first version it encounters in a file, so it can also be used for extracting the version from a CHANGELOG:

[tool.carthorse]
version-from = { name="file", path="CHANGELOG.md", pattern='## (?P<version>\d+\.\d+\.\d+)' }

none

This will return an empty string as the version. This is useful if you're using carthorse as a way of managing git tags or timestamped releases.

env

This will extract the version from the specified environment variable. For example, if you have constructed the version in $VERSION you could extract it with:

[tool.carthorse]
version-from = { name="env" }

If you need to extract it from an environment variable with a different name, for example $MYVERSION, you could extract it with:

[tool.carthorse]
version-from = { name="env", variable="MYVERSION" }

The tag-format configuration option lets you control the format of the version tag by specifying a python format string into which the version will be interpolated. The default is v{version}.

The names available to use in this are:

version

The version returned by the version extraction.

now

A python datetime for the current date and time.

Each check in the when configuration section will be performed in order. If any fail then no actions will be performed.

The following checks are currently available:

version_not_tagged

This will pass if no current git tag exists for the version extracted from the poject.

never

A safety net and testing helper, this check will never pass.

always

Useful if you basically want to skip the checking phase.

If all the checks pass, then the actions listed are executed in order. If an error occurs during the execution of an action, no further actions will be executed.

The following actions are currently available:

run

Run the specified command in a shell. The full environment will be passed through and $TAG will contain the tag computed from the tag format.

create_tag

This will create a git tag for the computed tag based on the extracted version and push it to the specified remote. By default, the origin remote is used.

If you are using carthorse to manage tags per environment, for example, you can ask for existing tags to be updated as follows:

[tool.carthorse]
actions = [
   { name="create-tag", update=true},
]

update_major_tag

This will create or update a major version tag based on the extracted version and force-push it to the specified remote. By default, the origin remote is used.

The major version is extracted from tag computed using the tag-format using a regular expression.

By default, the pattern used is 'v[0-9]+', but this can be configured.

Here's how you could use a different pattern and push to a different remote:

[tool.carthorse]
actions = [
   { name="update-major-tag", pattern='v\d\.\d', remote='upstream'},
]