diskimage-builder/diskimage_builder/elements.py

92 lines
3.0 KiB
Python
Raw Normal View History

# Copyright 2013 Hewlett-Packard Development Company, L.P.
# All Rights Reserved.
#
# 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.
import argparse
from errno import ENOENT
import os
import sys
def get_elements_dir():
if 'ELEMENTS_DIR' not in os.environ:
return os.path.abspath(
os.path.join(os.path.dirname(__file__), '..', 'elements'))
return os.environ['ELEMENTS_DIR']
def dependencies(element, elements_dir=None):
""" Return the non-transitive list of dependencies for a single element
:param user_elements: iterable enumerating elements a user has requested
: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.
"""
if elements_dir is None:
elements_dir = get_elements_dir()
element_deps_path = os.path.join(elements_dir, element, 'element-deps')
try:
with open(element_deps_path) as element_deps:
return set([line.strip() for line in element_deps])
except IOError as e:
if e.errno == 2:
return set()
else:
raise
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 = list(user_elements)
while check_queue:
element = check_queue.pop()
deps = dependencies(element, elements_dir)
check_queue.extend(deps - final_elements)
final_elements.update(deps)
return final_elements
def main(argv):
parser = argparse.ArgumentParser()
parser.add_argument('elements', nargs='+',
help='elements to inspect')
parser.add_argument('--expand-dependencies', '-d', action='store_true',
default=False,
help='Print expanded dependencies of all args')
args = parser.parse_args(argv[1:])
if args.expand_dependencies:
print(' '.join(expand_dependencies(args.elements)))
return 0
sys.stderr.write("ERROR: please choose an option.\n")
return -1