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Diffstat (limited to 'python/flask/cli.py')
| -rw-r--r-- | python/flask/cli.py | 910 |
1 files changed, 910 insertions, 0 deletions
diff --git a/python/flask/cli.py b/python/flask/cli.py new file mode 100644 index 0000000..3eb93b3 --- /dev/null +++ b/python/flask/cli.py @@ -0,0 +1,910 @@ +# -*- coding: utf-8 -*- +""" + flask.cli + ~~~~~~~~~ + + A simple command line application to run flask apps. + + :copyright: © 2010 by the Pallets team. + :license: BSD, see LICENSE for more details. +""" + +from __future__ import print_function + +import ast +import inspect +import os +import platform +import re +import ssl +import sys +import traceback +from functools import update_wrapper +from operator import attrgetter +from threading import Lock, Thread + +import click +from werkzeug.utils import import_string + +from . import __version__ +from ._compat import getargspec, iteritems, reraise, text_type +from .globals import current_app +from .helpers import get_debug_flag, get_env, get_load_dotenv + +try: + import dotenv +except ImportError: + dotenv = None + + +class NoAppException(click.UsageError): + """Raised if an application cannot be found or loaded.""" + + +def find_best_app(script_info, module): + """Given a module instance this tries to find the best possible + application in the module or raises an exception. + """ + from . import Flask + + # Search for the most common names first. + for attr_name in ('app', 'application'): + app = getattr(module, attr_name, None) + + if isinstance(app, Flask): + return app + + # Otherwise find the only object that is a Flask instance. + matches = [ + v for k, v in iteritems(module.__dict__) if isinstance(v, Flask) + ] + + if len(matches) == 1: + return matches[0] + elif len(matches) > 1: + raise NoAppException( + 'Detected multiple Flask applications in module "{module}". Use ' + '"FLASK_APP={module}:name" to specify the correct ' + 'one.'.format(module=module.__name__) + ) + + # Search for app factory functions. + for attr_name in ('create_app', 'make_app'): + app_factory = getattr(module, attr_name, None) + + if inspect.isfunction(app_factory): + try: + app = call_factory(script_info, app_factory) + + if isinstance(app, Flask): + return app + except TypeError: + if not _called_with_wrong_args(app_factory): + raise + raise NoAppException( + 'Detected factory "{factory}" in module "{module}", but ' + 'could not call it without arguments. Use ' + '"FLASK_APP=\'{module}:{factory}(args)\'" to specify ' + 'arguments.'.format( + factory=attr_name, module=module.__name__ + ) + ) + + raise NoAppException( + 'Failed to find Flask application or factory in module "{module}". ' + 'Use "FLASK_APP={module}:name to specify one.'.format( + module=module.__name__ + ) + ) + + +def call_factory(script_info, app_factory, arguments=()): + """Takes an app factory, a ``script_info` object and optionally a tuple + of arguments. Checks for the existence of a script_info argument and calls + the app_factory depending on that and the arguments provided. + """ + args_spec = getargspec(app_factory) + arg_names = args_spec.args + arg_defaults = args_spec.defaults + + if 'script_info' in arg_names: + return app_factory(*arguments, script_info=script_info) + elif arguments: + return app_factory(*arguments) + elif not arguments and len(arg_names) == 1 and arg_defaults is None: + return app_factory(script_info) + + return app_factory() + + +def _called_with_wrong_args(factory): + """Check whether calling a function raised a ``TypeError`` because + the call failed or because something in the factory raised the + error. + + :param factory: the factory function that was called + :return: true if the call failed + """ + tb = sys.exc_info()[2] + + try: + while tb is not None: + if tb.tb_frame.f_code is factory.__code__: + # in the factory, it was called successfully + return False + + tb = tb.tb_next + + # didn't reach the factory + return True + finally: + del tb + + +def find_app_by_string(script_info, module, app_name): + """Checks if the given string is a variable name or a function. If it is a + function, it checks for specified arguments and whether it takes a + ``script_info`` argument and calls the function with the appropriate + arguments. + """ + from flask import Flask + match = re.match(r'^ *([^ ()]+) *(?:\((.*?) *,? *\))? *$', app_name) + + if not match: + raise NoAppException( + '"{name}" is not a valid variable name or function ' + 'expression.'.format(name=app_name) + ) + + name, args = match.groups() + + try: + attr = getattr(module, name) + except AttributeError as e: + raise NoAppException(e.args[0]) + + if inspect.isfunction(attr): + if args: + try: + args = ast.literal_eval('({args},)'.format(args=args)) + except (ValueError, SyntaxError)as e: + raise NoAppException( + 'Could not parse the arguments in ' + '"{app_name}".'.format(e=e, app_name=app_name) + ) + else: + args = () + + try: + app = call_factory(script_info, attr, args) + except TypeError as e: + if not _called_with_wrong_args(attr): + raise + + raise NoAppException( + '{e}\nThe factory "{app_name}" in module "{module}" could not ' + 'be called with the specified arguments.'.format( + e=e, app_name=app_name, module=module.__name__ + ) + ) + else: + app = attr + + if isinstance(app, Flask): + return app + + raise NoAppException( + 'A valid Flask application was not obtained from ' + '"{module}:{app_name}".'.format( + module=module.__name__, app_name=app_name + ) + ) + + +def prepare_import(path): + """Given a filename this will try to calculate the python path, add it + to the search path and return the actual module name that is expected. + """ + path = os.path.realpath(path) + + if os.path.splitext(path)[1] == '.py': + path = os.path.splitext(path)[0] + + if os.path.basename(path) == '__init__': + path = os.path.dirname(path) + + module_name = [] + + # move up until outside package structure (no __init__.py) + while True: + path, name = os.path.split(path) + module_name.append(name) + + if not os.path.exists(os.path.join(path, '__init__.py')): + break + + if sys.path[0] != path: + sys.path.insert(0, path) + + return '.'.join(module_name[::-1]) + + +def locate_app(script_info, module_name, app_name, raise_if_not_found=True): + __traceback_hide__ = True + + try: + __import__(module_name) + except ImportError: + # Reraise the ImportError if it occurred within the imported module. + # Determine this by checking whether the trace has a depth > 1. + if sys.exc_info()[-1].tb_next: + raise NoAppException( + 'While importing "{name}", an ImportError was raised:' + '\n\n{tb}'.format(name=module_name, tb=traceback.format_exc()) + ) + elif raise_if_not_found: + raise NoAppException( + 'Could not import "{name}".'.format(name=module_name) + ) + else: + return + + module = sys.modules[module_name] + + if app_name is None: + return find_best_app(script_info, module) + else: + return find_app_by_string(script_info, module, app_name) + + +def get_version(ctx, param, value): + if not value or ctx.resilient_parsing: + return + import werkzeug + message = ( + 'Python %(python)s\n' + 'Flask %(flask)s\n' + 'Werkzeug %(werkzeug)s' + ) + click.echo(message % { + 'python': platform.python_version(), + 'flask': __version__, + 'werkzeug': werkzeug.__version__, + }, color=ctx.color) + ctx.exit() + + +version_option = click.Option( + ['--version'], + help='Show the flask version', + expose_value=False, + callback=get_version, + is_flag=True, + is_eager=True +) + + +class DispatchingApp(object): + """Special application that dispatches to a Flask application which + is imported by name in a background thread. If an error happens + it is recorded and shown as part of the WSGI handling which in case + of the Werkzeug debugger means that it shows up in the browser. + """ + + def __init__(self, loader, use_eager_loading=False): + self.loader = loader + self._app = None + self._lock = Lock() + self._bg_loading_exc_info = None + if use_eager_loading: + self._load_unlocked() + else: + self._load_in_background() + + def _load_in_background(self): + def _load_app(): + __traceback_hide__ = True + with self._lock: + try: + self._load_unlocked() + except Exception: + self._bg_loading_exc_info = sys.exc_info() + t = Thread(target=_load_app, args=()) + t.start() + + def _flush_bg_loading_exception(self): + __traceback_hide__ = True + exc_info = self._bg_loading_exc_info + if exc_info is not None: + self._bg_loading_exc_info = None + reraise(*exc_info) + + def _load_unlocked(self): + __traceback_hide__ = True + self._app = rv = self.loader() + self._bg_loading_exc_info = None + return rv + + def __call__(self, environ, start_response): + __traceback_hide__ = True + if self._app is not None: + return self._app(environ, start_response) + self._flush_bg_loading_exception() + with self._lock: + if self._app is not None: + rv = self._app + else: + rv = self._load_unlocked() + return rv(environ, start_response) + + +class ScriptInfo(object): + """Helper object to deal with Flask applications. This is usually not + necessary to interface with as it's used internally in the dispatching + to click. In future versions of Flask this object will most likely play + a bigger role. Typically it's created automatically by the + :class:`FlaskGroup` but you can also manually create it and pass it + onwards as click object. + """ + + def __init__(self, app_import_path=None, create_app=None, + set_debug_flag=True): + #: Optionally the import path for the Flask application. + self.app_import_path = app_import_path or os.environ.get('FLASK_APP') + #: Optionally a function that is passed the script info to create + #: the instance of the application. + self.create_app = create_app + #: A dictionary with arbitrary data that can be associated with + #: this script info. + self.data = {} + self.set_debug_flag = set_debug_flag + self._loaded_app = None + + def load_app(self): + """Loads the Flask app (if not yet loaded) and returns it. Calling + this multiple times will just result in the already loaded app to + be returned. + """ + __traceback_hide__ = True + + if self._loaded_app is not None: + return self._loaded_app + + app = None + + if self.create_app is not None: + app = call_factory(self, self.create_app) + else: + if self.app_import_path: + path, name = (re.split(r':(?![\\/])', self.app_import_path, 1) + [None])[:2] + import_name = prepare_import(path) + app = locate_app(self, import_name, name) + else: + for path in ('wsgi.py', 'app.py'): + import_name = prepare_import(path) + app = locate_app(self, import_name, None, + raise_if_not_found=False) + + if app: + break + + if not app: + raise NoAppException( + 'Could not locate a Flask application. You did not provide ' + 'the "FLASK_APP" environment variable, and a "wsgi.py" or ' + '"app.py" module was not found in the current directory.' + ) + + if self.set_debug_flag: + # Update the app's debug flag through the descriptor so that + # other values repopulate as well. + app.debug = get_debug_flag() + + self._loaded_app = app + return app + + +pass_script_info = click.make_pass_decorator(ScriptInfo, ensure=True) + + +def with_appcontext(f): + """Wraps a callback so that it's guaranteed to be executed with the + script's application context. If callbacks are registered directly + to the ``app.cli`` object then they are wrapped with this function + by default unless it's disabled. + """ + @click.pass_context + def decorator(__ctx, *args, **kwargs): + with __ctx.ensure_object(ScriptInfo).load_app().app_context(): + return __ctx.invoke(f, *args, **kwargs) + return update_wrapper(decorator, f) + + +class AppGroup(click.Group): + """This works similar to a regular click :class:`~click.Group` but it + changes the behavior of the :meth:`command` decorator so that it + automatically wraps the functions in :func:`with_appcontext`. + + Not to be confused with :class:`FlaskGroup`. + """ + + def command(self, *args, **kwargs): + """This works exactly like the method of the same name on a regular + :class:`click.Group` but it wraps callbacks in :func:`with_appcontext` + unless it's disabled by passing ``with_appcontext=False``. + """ + wrap_for_ctx = kwargs.pop('with_appcontext', True) + def decorator(f): + if wrap_for_ctx: + f = with_appcontext(f) + return click.Group.command(self, *args, **kwargs)(f) + return decorator + + def group(self, *args, **kwargs): + """This works exactly like the method of the same name on a regular + :class:`click.Group` but it defaults the group class to + :class:`AppGroup`. + """ + kwargs.setdefault('cls', AppGroup) + return click.Group.group(self, *args, **kwargs) + + +class FlaskGroup(AppGroup): + """Special subclass of the :class:`AppGroup` group that supports + loading more commands from the configured Flask app. Normally a + developer does not have to interface with this class but there are + some very advanced use cases for which it makes sense to create an + instance of this. + + For information as of why this is useful see :ref:`custom-scripts`. + + :param add_default_commands: if this is True then the default run and + shell commands wil be added. + :param add_version_option: adds the ``--version`` option. + :param create_app: an optional callback that is passed the script info and + returns the loaded app. + :param load_dotenv: Load the nearest :file:`.env` and :file:`.flaskenv` + files to set environment variables. Will also change the working + directory to the directory containing the first file found. + :param set_debug_flag: Set the app's debug flag based on the active + environment + + .. versionchanged:: 1.0 + If installed, python-dotenv will be used to load environment variables + from :file:`.env` and :file:`.flaskenv` files. + """ + + def __init__(self, add_default_commands=True, create_app=None, + add_version_option=True, load_dotenv=True, + set_debug_flag=True, **extra): + params = list(extra.pop('params', None) or ()) + + if add_version_option: + params.append(version_option) + + AppGroup.__init__(self, params=params, **extra) + self.create_app = create_app + self.load_dotenv = load_dotenv + self.set_debug_flag = set_debug_flag + + if add_default_commands: + self.add_command(run_command) + self.add_command(shell_command) + self.add_command(routes_command) + + self._loaded_plugin_commands = False + + def _load_plugin_commands(self): + if self._loaded_plugin_commands: + return + try: + import pkg_resources + except ImportError: + self._loaded_plugin_commands = True + return + + for ep in pkg_resources.iter_entry_points('flask.commands'): + self.add_command(ep.load(), ep.name) + self._loaded_plugin_commands = True + + def get_command(self, ctx, name): + self._load_plugin_commands() + + # We load built-in commands first as these should always be the + # same no matter what the app does. If the app does want to + # override this it needs to make a custom instance of this group + # and not attach the default commands. + # + # This also means that the script stays functional in case the + # application completely fails. + rv = AppGroup.get_command(self, ctx, name) + if rv is not None: + return rv + + info = ctx.ensure_object(ScriptInfo) + try: + rv = info.load_app().cli.get_command(ctx, name) + if rv is not None: + return rv + except NoAppException: + pass + + def list_commands(self, ctx): + self._load_plugin_commands() + + # The commands available is the list of both the application (if + # available) plus the builtin commands. + rv = set(click.Group.list_commands(self, ctx)) + info = ctx.ensure_object(ScriptInfo) + try: + rv.update(info.load_app().cli.list_commands(ctx)) + except Exception: + # Here we intentionally swallow all exceptions as we don't + # want the help page to break if the app does not exist. + # If someone attempts to use the command we try to create + # the app again and this will give us the error. + # However, we will not do so silently because that would confuse + # users. + traceback.print_exc() + return sorted(rv) + + def main(self, *args, **kwargs): + # Set a global flag that indicates that we were invoked from the + # command line interface. This is detected by Flask.run to make the + # call into a no-op. This is necessary to avoid ugly errors when the + # script that is loaded here also attempts to start a server. + os.environ['FLASK_RUN_FROM_CLI'] = 'true' + + if get_load_dotenv(self.load_dotenv): + load_dotenv() + + obj = kwargs.get('obj') + + if obj is None: + obj = ScriptInfo(create_app=self.create_app, + set_debug_flag=self.set_debug_flag) + + kwargs['obj'] = obj + kwargs.setdefault('auto_envvar_prefix', 'FLASK') + return super(FlaskGroup, self).main(*args, **kwargs) + + +def _path_is_ancestor(path, other): + """Take ``other`` and remove the length of ``path`` from it. Then join it + to ``path``. If it is the original value, ``path`` is an ancestor of + ``other``.""" + return os.path.join(path, other[len(path):].lstrip(os.sep)) == other + + +def load_dotenv(path=None): + """Load "dotenv" files in order of precedence to set environment variables. + + If an env var is already set it is not overwritten, so earlier files in the + list are preferred over later files. + + Changes the current working directory to the location of the first file + found, with the assumption that it is in the top level project directory + and will be where the Python path should import local packages from. + + This is a no-op if `python-dotenv`_ is not installed. + + .. _python-dotenv: https://github.com/theskumar/python-dotenv#readme + + :param path: Load the file at this location instead of searching. + :return: ``True`` if a file was loaded. + + .. versionadded:: 1.0 + """ + if dotenv is None: + if path or os.path.exists('.env') or os.path.exists('.flaskenv'): + click.secho( + ' * Tip: There are .env files present.' + ' Do "pip install python-dotenv" to use them.', + fg='yellow') + return + + if path is not None: + return dotenv.load_dotenv(path) + + new_dir = None + + for name in ('.env', '.flaskenv'): + path = dotenv.find_dotenv(name, usecwd=True) + + if not path: + continue + + if new_dir is None: + new_dir = os.path.dirname(path) + + dotenv.load_dotenv(path) + + if new_dir and os.getcwd() != new_dir: + os.chdir(new_dir) + + return new_dir is not None # at least one file was located and loaded + + +def show_server_banner(env, debug, app_import_path, eager_loading): + """Show extra startup messages the first time the server is run, + ignoring the reloader. + """ + if os.environ.get('WERKZEUG_RUN_MAIN') == 'true': + return + + if app_import_path is not None: + message = ' * Serving Flask app "{0}"'.format(app_import_path) + + if not eager_loading: + message += ' (lazy loading)' + + click.echo(message) + + click.echo(' * Environment: {0}'.format(env)) + + if env == 'production': + click.secho( + ' WARNING: This is a development server. ' + 'Do not use it in a production deployment.', fg='red') + click.secho(' Use a production WSGI server instead.', dim=True) + + if debug is not None: + click.echo(' * Debug mode: {0}'.format('on' if debug else 'off')) + + +class CertParamType(click.ParamType): + """Click option type for the ``--cert`` option. Allows either an + existing file, the string ``'adhoc'``, or an import for a + :class:`~ssl.SSLContext` object. + """ + + name = 'path' + + def __init__(self): + self.path_type = click.Path( + exists=True, dir_okay=False, resolve_path=True) + + def convert(self, value, param, ctx): + try: + return self.path_type(value, param, ctx) + except click.BadParameter: + value = click.STRING(value, param, ctx).lower() + + if value == 'adhoc': + try: + import OpenSSL + except ImportError: + raise click.BadParameter( + 'Using ad-hoc certificates requires pyOpenSSL.', + ctx, param) + + return value + + obj = import_string(value, silent=True) + + if sys.version_info < (2, 7, 9): + if obj: + return obj + else: + if isinstance(obj, ssl.SSLContext): + return obj + + raise + + +def _validate_key(ctx, param, value): + """The ``--key`` option must be specified when ``--cert`` is a file. + Modifies the ``cert`` param to be a ``(cert, key)`` pair if needed. + """ + cert = ctx.params.get('cert') + is_adhoc = cert == 'adhoc' + + if sys.version_info < (2, 7, 9): + is_context = cert and not isinstance(cert, (text_type, bytes)) + else: + is_context = isinstance(cert, ssl.SSLContext) + + if value is not None: + if is_adhoc: + raise click.BadParameter( + 'When "--cert" is "adhoc", "--key" is not used.', + ctx, param) + + if is_context: + raise click.BadParameter( + 'When "--cert" is an SSLContext object, "--key is not used.', + ctx, param) + + if not cert: + raise click.BadParameter( + '"--cert" must also be specified.', + ctx, param) + + ctx.params['cert'] = cert, value + + else: + if cert and not (is_adhoc or is_context): + raise click.BadParameter( + 'Required when using "--cert".', + ctx, param) + + return value + + +@click.command('run', short_help='Run a development server.') +@click.option('--host', '-h', default='127.0.0.1', + help='The interface to bind to.') +@click.option('--port', '-p', default=5000, + help='The port to bind to.') +@click.option('--cert', type=CertParamType(), + help='Specify a certificate file to use HTTPS.') +@click.option('--key', + type=click.Path(exists=True, dir_okay=False, resolve_path=True), + callback=_validate_key, expose_value=False, + help='The key file to use when specifying a certificate.') +@click.option('--reload/--no-reload', default=None, + help='Enable or disable the reloader. By default the reloader ' + 'is active if debug is enabled.') +@click.option('--debugger/--no-debugger', default=None, + help='Enable or disable the debugger. By default the debugger ' + 'is active if debug is enabled.') +@click.option('--eager-loading/--lazy-loader', default=None, + help='Enable or disable eager loading. By default eager ' + 'loading is enabled if the reloader is disabled.') +@click.option('--with-threads/--without-threads', default=True, + help='Enable or disable multithreading.') +@pass_script_info +def run_command(info, host, port, reload, debugger, eager_loading, + with_threads, cert): + """Run a local development server. + + This server is for development purposes only. It does not provide + the stability, security, or performance of production WSGI servers. + + The reloader and debugger are enabled by default if + FLASK_ENV=development or FLASK_DEBUG=1. + """ + debug = get_debug_flag() + + if reload is None: + reload = debug + + if debugger is None: + debugger = debug + + if eager_loading is None: + eager_loading = not reload + + show_server_banner(get_env(), debug, info.app_import_path, eager_loading) + app = DispatchingApp(info.load_app, use_eager_loading=eager_loading) + + from werkzeug.serving import run_simple + run_simple(host, port, app, use_reloader=reload, use_debugger=debugger, + threaded=with_threads, ssl_context=cert) + + +@click.command('shell', short_help='Run a shell in the app context.') +@with_appcontext +def shell_command(): + """Run an interactive Python shell in the context of a given + Flask application. The application will populate the default + namespace of this shell according to it's configuration. + + This is useful for executing small snippets of management code + without having to manually configure the application. + """ + import code + from flask.globals import _app_ctx_stack + app = _app_ctx_stack.top.app + banner = 'Python %s on %s\nApp: %s [%s]\nInstance: %s' % ( + sys.version, + sys.platform, + app.import_name, + app.env, + app.instance_path, + ) + ctx = {} + + # Support the regular Python interpreter startup script if someone + # is using it. + startup = os.environ.get('PYTHONSTARTUP') + if startup and os.path.isfile(startup): + with open(startup, 'r') as f: + eval(compile(f.read(), startup, 'exec'), ctx) + + ctx.update(app.make_shell_context()) + + code.interact(banner=banner, local=ctx) + + +@click.command('routes', short_help='Show the routes for the app.') +@click.option( + '--sort', '-s', + type=click.Choice(('endpoint', 'methods', 'rule', 'match')), + default='endpoint', + help=( + 'Method to sort routes by. "match" is the order that Flask will match ' + 'routes when dispatching a request.' + ) +) +@click.option( + '--all-methods', + is_flag=True, + help="Show HEAD and OPTIONS methods." +) +@with_appcontext +def routes_command(sort, all_methods): + """Show all registered routes with endpoints and methods.""" + + rules = list(current_app.url_map.iter_rules()) + if not rules: + click.echo('No routes were registered.') + return + + ignored_methods = set(() if all_methods else ('HEAD', 'OPTIONS')) + + if sort in ('endpoint', 'rule'): + rules = sorted(rules, key=attrgetter(sort)) + elif sort == 'methods': + rules = sorted(rules, key=lambda rule: sorted(rule.methods)) + + rule_methods = [ + ', '.join(sorted(rule.methods - ignored_methods)) for rule in rules + ] + + headers = ('Endpoint', 'Methods', 'Rule') + widths = ( + max(len(rule.endpoint) for rule in rules), + max(len(methods) for methods in rule_methods), + max(len(rule.rule) for rule in rules), + ) + widths = [max(len(h), w) for h, w in zip(headers, widths)] + row = '{{0:<{0}}} {{1:<{1}}} {{2:<{2}}}'.format(*widths) + + click.echo(row.format(*headers).strip()) + click.echo(row.format(*('-' * width for width in widths))) + + for rule, methods in zip(rules, rule_methods): + click.echo(row.format(rule.endpoint, methods, rule.rule).rstrip()) + + +cli = FlaskGroup(help="""\ +A general utility script for Flask applications. + +Provides commands from Flask, extensions, and the application. Loads the +application defined in the FLASK_APP environment variable, or from a wsgi.py +file. Setting the FLASK_ENV environment variable to 'development' will enable +debug mode. + +\b + {prefix}{cmd} FLASK_APP=hello.py + {prefix}{cmd} FLASK_ENV=development + {prefix}flask run +""".format( + cmd='export' if os.name == 'posix' else 'set', + prefix='$ ' if os.name == 'posix' else '> ' +)) + + +def main(as_module=False): + args = sys.argv[1:] + + if as_module: + this_module = 'flask' + + if sys.version_info < (2, 7): + this_module += '.cli' + + name = 'python -m ' + this_module + + # Python rewrites "python -m flask" to the path to the file in argv. + # Restore the original command so that the reloader works. + sys.argv = ['-m', this_module] + args + else: + name = None + + cli.main(args=args, prog_name=name) + + +if __name__ == '__main__': + main(as_module=True) |