# 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 errno
import logging
import os
import sys
import yaml
import diskimage_builder.logging_config
logger = logging.getLogger(__name__)
class Element(object):
"""An element"""
def __init__(self, name, path):
"""A new element
:param name: The element name
:param path: Full path to element. element-deps and
element-provides files will be parsed
"""
self.name = name
self.path = path
self.provides = set()
self.depends = set()
# read the provides & depends files for this element into a
# set; if the element has them.
provides = os.path.join(path, 'element-provides')
depends = os.path.join(path, 'element-deps')
try:
with open(provides) as p:
self.provides = set([line.strip() for line in p])
except IOError as e:
if e.errno == errno.ENOENT:
pass
else:
raise
try:
with open(depends) as d:
self.depends = set([line.strip() for line in d])
except IOError as e:
if e.errno == errno.ENOENT:
pass
else:
raise
logger.debug("New element : %s", str(self))
def __str__(self):
return '%s p:<%s> d:<%s>' % (self.name,
','.join(self.provides),
','.join(self.depends))
def get_elements_dir():
if not os.environ.get('ELEMENTS_PATH'):
raise Exception("$ELEMENTS_PATH must be set.")
return os.environ['ELEMENTS_PATH']
def expand_dependencies(user_elements, all_elements):
"""Expand user requested elements using element-deps files.
Arguments:
:param user_elements: iterable enumerating the elements a user requested
:param all_elements: Element object dictionary from find_all_elements
:return: a set containing the names of 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
elif element not in all_elements:
logger.error("Element '%s' not found", element)
sys.exit(1)
element_obj = all_elements[element]
element_deps = element_obj.depends
element_provides = element_obj.provides
# 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 find_all_elements(paths=None):
"""Build a dictionary Element() objects
Walk ELEMENTS_PATH and find all elements. Make an Element object
for each element we wish to consider. Note we process overrides
such that elements specified earlier in the ELEMENTS_PATH override
those seen later.
:param paths: A list of paths to find elements in. If None will
use ELEMENTS_PATH
:return: a dictionary of all elements
"""
all_elements = {}
# note we process the later entries *first*, so that earlier
# entries will override later ones. i.e. with
# ELEMENTS_PATH=path1:path2:path3
# we want the elements in "path1" to override "path3"
if not paths:
paths = reversed(get_elements_dir().split(':'))
for path in paths:
if not os.path.isdir(path):
logger.error("ELEMENT_PATH entry '%s' is not a directory", path)
sys.exit(1)
# In words : make a list of directories in "path". Since an
# element is a directory, this is our list of elements.
elements = [os.path.realpath(os.path.join(path, f))
for f in os.listdir(path)
if os.path.isdir(os.path.join(path, f))]
for element in elements:
# the element name is the last part of the full path in
# element (these are all directories, we know that from
# above)
name = os.path.basename(element)
new_element = Element(name, element)
if name in all_elements:
logger.warning("Element <%s> overrides <%s>",
new_element.path, all_elements[name].path)
all_elements[name] = new_element
return all_elements
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'))
parser.add_argument('--env', '-e', action='store_true',
default=False,
help=('Output eval-able bash strings for '
'IMAGE_ELEMENT variables'))
args = parser.parse_args(argv[1:])
all_elements = find_all_elements()
if args.expand_dependencies:
logger.warning("expand-dependencies flag is deprecated, "
"and is now on by default.", file=sys.stderr)
elements = expand_dependencies(args.elements, all_elements)
if args.env:
# first the "legacy" environment variable that just lists the
# elements
print("export IMAGE_ELEMENT='%s'" % ' '.join(elements))
# Then YAML
output = {}
for element in elements:
output[element] = all_elements[element].path
print("export IMAGE_ELEMENT_YAML='%s'" % yaml.safe_dump(output))
# Then bash array. Unfortunately, bash can't export array
# variables. So we take a compromise and produce an exported
# function that outputs the string to re-create the array.
# You can then simply do
# eval declare -A element_array=$(get_image_element_array)
# and you have it.
output = ""
for element in elements:
output += '[%s]=%s ' % (element, all_elements[element].path)
print("function get_image_element_array {\n"
" echo \"%s\"\n"
"};\n"
"export -f get_image_element_array;" % output)
else:
print(' '.join(elements))
return 0