Lore Environment

Lore maintains an independent python virtualenv for each app, along with several ways to set environment variables that allow Lore apps apps to be 100% replicated from development to production, without any day to day effort on the behalf of developers. There is no manual activation, or magic env vars, or hidden files that break python for everything else. No knowledge required of venv, pyenv, pyvenv, virtualenv, virtualenvwrapper, pipenv, conda. Ain’t nobody got time for that.

The first thing lore does when launched from a command line, is to find the correct virtualenv, with the perfect set of dependencies and relaunch the same command in that environment. Virtualenv names are based on the Lore app name, so if you have two apps with the same name, they will share a virtualenv by default.

lore.env provides constants to make working with the correct executables easy. The most common is lore.env.NAME.

lore.env.APP = 'stable'

The name of this Lore app

lore.env.BIN_FLASK = u'/home/docs/.pyenv/versions/3.6.6/envs/stable/bin/flask'

path to virtualenv flask executable

lore.env.BIN_JUPYTER = u'/home/docs/.pyenv/versions/3.6.6/envs/stable/bin/jupyter'

path to virtualenv jupyter executable

lore.env.BIN_LORE = u'/home/docs/.pyenv/versions/3.6.6/envs/stable/bin/lore'

path to virtualenv lore executable

lore.env.BIN_PYENV = u'/home/docs/.pyenv/bin/pyenv'

path to pyenv executable

lore.env.BIN_PYTHON = u'/home/docs/.pyenv/versions/3.6.6/envs/stable/bin/python'

path to virtualenv python executable

lore.env.COLOR = 32

color code environment names for logging

lore.env.DATA_DIR = u'./data'

disk based caching and data dependencies

lore.env.DEFAULT_NAME = u'development'

the environment you get when you just can’t be bothered to care

lore.env.DEVELOPMENT = u'development'

environment for mucking about

lore.env.ENV_DIRECTORY = u'/conf/env'

more environment variables will be loaded from files in this directory

lore.env.ENV_FILE = u'./.env'

environment variables will be loaded from this file first

lore.env.FLASK_APP = u'/home/docs/.pyenv/versions/3.6.6/envs/stable/lib/python3.6/site-packages/lore/www/__init__.py'

path to the current lore app’s flask app

lore.env.HOME = u'/home/User'

HOME directory of the current user or ROOT if unset

lore.env.HOST = u'localhost'

current machine name: socket.gethostname

lore.env.JUPYTER_KERNEL_PATH = u'/'

location of jupyter kernels

lore.env.LIB = u'/home/docs/checkouts/readthedocs.org/user_builds/lore-machine-learning/checkouts/stable/lib'

packages in ./lib are also available for import in the Lore app.

lore.env.LOG_DIR = u'./logs'

log file storage

lore.env.MODELS_DIR = u'./models'

disk based model store

lore.env.NAME = u'development'

current environment name, e.g. 'development', 'test', 'production'

lore.env.PREFIX = u'/home/docs/.pyenv/versions/3.6.6/envs/stable'

path to the Lore app virtualenv

lore.env.PRODUCTION = u'production'

environment that actually matters

lore.env.PYENV = '/home/docs/.pyenv'

Path to pyenv root

lore.env.PYTHON_VERSION = u'2.7.16'

Version of python required by this Lore app.

lore.env.PYTHON_VERSION_INFO = [2, 7, 16]

Parsed version of python required by this Lore app.

lore.env.REQUIREMENTS = u'./requirements.txt'

requirement files

lore.env.ROOT = u'.'

Relative root for all app files. Determined by LORE_ROOT, or iterating up directories until a runtime.txt is found. If no runtime.txt is found os.getcwd is used.

lore.env.STDOUT_EXCEPTIONS = True

exceptions are always logged, in addition they can be printed to any:sys.stdout

lore.env.TEST = u'test'

environment that definitely should reflect exactly what happens in production

lore.env.TESTS_DIR = u'./tests'

Lore app test suite

lore.env.UNICODE_LOCALE = True

does the current python locale support unicode?

lore.env.UNICODE_UPGRADED = False

did lore change current system locale for unicode support?

lore.env.VERSION_PATH = u'runtime.txt'

Path to the specification of this apps Python version.

lore.env.WORK_DIR = u'.'

root for disk based work

lore.env.check_requirements()

Make sure all listed packages from requirements.txt have been installed into the virtualenv at boot.

lore.env.check_version()

Sanity check version information for corrupt virtualenv symlinks

lore.env.exists()

Test whether a lore environmnet can be found from the current working directory.

Returns:True if the environment exists Return type:bool

lore.env.extend_path()

Adds Lore App modules to the path to making importing easy, including LIB

lore.env.get_config(path)

Load a config from disk

Parameters:path (unicode) – target config Returns: Return type:configparser.Config

lore.env.launch()

Ensure that python is running from the Lore virtualenv past this point.

lore.env.launched()

Test whether the current python environment is the correct lore env.

Returns:True if the environment is launched Return type:bool

lore.env.load_env_directory()

Adds environment variables defined in ENV_DIRECTORY to os.environ. Each file will be added to os.environ via filename = contents. Supports bash style comments and variable interpolation.

lore.env.load_env_file()

Adds environment variables defined in ENV_FILE to os.environ. Supports bash style comments and variable interpolation.

lore.env.read_version(path)

Attempts to read a python version string from a runtime.txt file

Parameters:path – to source of the string Returns:python version Return type:unicode or None

lore.env.reboot(*args)

Reboot python in the Lore virtualenv

lore.env.require(packages)

Ensures that a pypi package has been installed into the App’s python environment. If not, the package will be installed and your env will be rebooted.

Example:

lore.env.require('pandas')
# -> pandas is required. Dependencies added to requirements.txt

Parameters:packages ([unicode]) – requirements.txt style name and versions of packages

lore.env.set_installed_packages()

Idempotently caches the list of packages installed in the virtualenv. Can be run safely before the virtualenv is created, and will be rerun afterwards.

lore.env.validate()

Display error messages and exit if no lore environment can be found.