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# Copyright 2014-2015 Canonical Limited.
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# This file is part of charm-helpers.
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# charm-helpers is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Lesser General Public License version 3 as
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# published by the Free Software Foundation.
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# charm-helpers is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Lesser General Public License for more details.
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# You should have received a copy of the GNU Lesser General Public License
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# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
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from six.moves import zip
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from charmhelpers.core import unitdata
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class OutputFormatter(object):
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def __init__(self, outfile=sys.stdout):
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self.outfile = outfile
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def add_arguments(self, argument_parser):
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formatgroup = argument_parser.add_mutually_exclusive_group()
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choices = self.supported_formats
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formatgroup.add_argument("--format", metavar='FMT',
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help="Select output format for returned data, "
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"where FMT is one of: {}".format(choices),
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choices=choices, default='raw')
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for fmt in self.formats:
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fmtfunc = getattr(self, fmt)
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formatgroup.add_argument("-{}".format(fmt[0]),
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"--{}".format(fmt), action='store_const',
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const=fmt, dest='format',
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def supported_formats(self):
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def raw(self, output):
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"""Output data as raw string (default)"""
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if isinstance(output, (list, tuple)):
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output = '\n'.join(map(str, output))
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self.outfile.write(str(output))
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"""Output data as a nicely-formatted python data structure"""
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pprint.pprint(output, stream=self.outfile)
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def json(self, output):
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"""Output data in JSON format"""
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json.dump(output, self.outfile)
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def yaml(self, output):
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"""Output data in YAML format"""
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yaml.safe_dump(output, self.outfile)
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def csv(self, output):
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"""Output data as excel-compatible CSV"""
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csvwriter = csv.writer(self.outfile)
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csvwriter.writerows(output)
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def tab(self, output):
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"""Output data in excel-compatible tab-delimited format"""
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csvwriter = csv.writer(self.outfile, dialect=csv.excel_tab)
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csvwriter.writerows(output)
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def format_output(self, output, fmt='raw'):
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fmtfunc = getattr(self, fmt)
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class CommandLine(object):
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argument_parser = None
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if not self.argument_parser:
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self.argument_parser = argparse.ArgumentParser(description='Perform common charm tasks')
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if not self.formatter:
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self.formatter = OutputFormatter()
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self.formatter.add_arguments(self.argument_parser)
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if not self.subparsers:
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self.subparsers = self.argument_parser.add_subparsers(help='Commands')
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def subcommand(self, command_name=None):
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Decorate a function as a subcommand. Use its arguments as the
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command-line arguments"""
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def wrapper(decorated):
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cmd_name = command_name or decorated.__name__
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subparser = self.subparsers.add_parser(cmd_name,
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description=decorated.__doc__)
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for args, kwargs in describe_arguments(decorated):
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subparser.add_argument(*args, **kwargs)
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subparser.set_defaults(func=decorated)
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def test_command(self, decorated):
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Subcommand is a boolean test function, so bool return values should be
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converted to a 0/1 exit code.
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decorated._cli_test_command = True
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def no_output(self, decorated):
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Subcommand is not expected to return a value, so don't print a spurious None.
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decorated._cli_no_output = True
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def subcommand_builder(self, command_name, description=None):
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Decorate a function that builds a subcommand. Builders should accept a
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single argument (the subparser instance) and return the function to be
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run as the command."""
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def wrapper(decorated):
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subparser = self.subparsers.add_parser(command_name)
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func = decorated(subparser)
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subparser.set_defaults(func=func)
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subparser.description = description or func.__doc__
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"Run cli, processing arguments and executing subcommands."
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arguments = self.argument_parser.parse_args()
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argspec = inspect.getargspec(arguments.func)
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for arg in argspec.args:
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vargs.append(getattr(arguments, arg))
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vargs.extend(getattr(arguments, argspec.varargs))
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output = arguments.func(*vargs)
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if getattr(arguments.func, '_cli_test_command', False):
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self.exit_code = 0 if output else 1
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if getattr(arguments.func, '_cli_no_output', False):
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self.formatter.format_output(output, arguments.format)
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cmdline = CommandLine()
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def describe_arguments(func):
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Analyze a function's signature and return a data structure suitable for
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passing in as arguments to an argparse parser's add_argument() method."""
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argspec = inspect.getargspec(func)
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# we should probably raise an exception somewhere if func includes **kwargs
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positional_args = argspec.args[:-len(argspec.defaults)]
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keyword_names = argspec.args[-len(argspec.defaults):]
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for arg, default in zip(keyword_names, argspec.defaults):
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yield ('--{}'.format(arg),), {'default': default}
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positional_args = argspec.args
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for arg in positional_args:
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yield (argspec.varargs,), {'nargs': '*'}
added
removed
hooks/charmhelpers/cli/__init__.py
