diskimage-builder/diskimage_builder/element_dependencies.py
Ian Wienand 452f7b8d5a Clear up "already provided" message
I got quite confused what this was trying to tell me at first.  It's
saying that you requested an element but another element already
provides that element, so we don't know which one to choose.

To help clarify the situation to the user, keep track of what is
providing elements so we can describe where the conflict came from.

Change-Id: Ie7471ac900a8cbee5684c928badd1b8ce6d3e3cf
2016-07-01 11:53:07 +10:00

147 lines
5.1 KiB
Python

# Copyright 2013 Hewlett-Packard Development Company, L.P.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
from __future__ import print_function
import argparse
import collections
import logging
import os
import sys
import diskimage_builder.logging_config
logger = logging.getLogger(__name__)
def get_elements_dir():
if not os.environ.get('ELEMENTS_PATH'):
raise Exception("$ELEMENTS_PATH must be set.")
return os.environ['ELEMENTS_PATH']
def _get_set(element, fname, elements_dir=None):
if elements_dir is None:
elements_dir = get_elements_dir()
for path in elements_dir.split(':'):
element_deps_path = (os.path.join(path, element, fname))
try:
with open(element_deps_path) as element_deps:
return set([line.strip() for line in element_deps])
except IOError as e:
if os.path.exists(os.path.join(path, element)) and e.errno == 2:
return set()
if e.errno == 2:
continue
else:
raise
logger.error("Element '%s' not found in '%s'" % (element, elements_dir))
sys.exit(-1)
def provides(element, elements_dir=None):
"""Return the set of elements provided by the specified element.
:param element: name of a single element
:param elements_dir: the elements dir to read from. If not supplied,
inferred by calling get_elements_dir().
:return: a set just containing all elements that the specified element
provides.
"""
return _get_set(element, 'element-provides', elements_dir)
def dependencies(element, elements_dir=None):
"""Return the non-transitive set of dependencies for a single element.
:param element: name of a single element
:param elements_dir: the elements dir to read from. If not supplied,
inferred by calling get_elements_dir().
:return: a set just containing all elements that the specified element
depends on.
"""
return _get_set(element, 'element-deps', elements_dir)
def expand_dependencies(user_elements, elements_dir=None):
"""Expand user requested elements using element-deps files.
Arguments:
:param user_elements: iterable enumerating the elements a user requested
:param elements_dir: the elements dir to read from. Passed directly to
dependencies()
:return: a set containing user_elements and all dependent elements
including any transitive dependencies.
"""
final_elements = set(user_elements)
check_queue = collections.deque(user_elements)
provided = set()
provided_by = collections.defaultdict(list)
while check_queue:
# bug #1303911 - run through the provided elements first to avoid
# adding unwanted dependencies and looking for virtual elements
element = check_queue.popleft()
if element in provided:
continue
element_deps = dependencies(element, elements_dir)
element_provides = provides(element, elements_dir)
# save which elements provide another element for potential
# error message
for provide in element_provides:
provided_by[provide].append(element)
provided.update(element_provides)
check_queue.extend(element_deps - (final_elements | provided))
final_elements.update(element_deps)
if "operating-system" not in provided:
logger.error(
"Please include an operating system element.")
sys.exit(-1)
conflicts = set(user_elements) & provided
if conflicts:
logger.error(
"The following elements are already provided by another element")
for element in conflicts:
logger.error("%s : already provided by %s" %
(element, provided_by[element]))
sys.exit(-1)
return final_elements - provided
def main(argv):
diskimage_builder.logging_config.setup()
parser = argparse.ArgumentParser()
parser.add_argument('elements', nargs='+',
help='display dependencies of the given elements')
parser.add_argument('--expand-dependencies', '-d', action='store_true',
default=False,
help=('(DEPRECATED) print expanded dependencies '
'of all args'))
args = parser.parse_args(argv[1:])
if args.expand_dependencies:
logger.warning("expand-dependencies flag is deprecated, "
"and is now on by default.", file=sys.stderr)
print(' '.join(expand_dependencies(args.elements)))
return 0