cdist/cdist/emulator.py
2017-08-12 23:02:31 +02:00

324 lines
13 KiB
Python

# -*- coding: utf-8 -*-
#
# 2011-2015 Nico Schottelius (nico-cdist at schottelius.org)
# 2012-2013 Steven Armstrong (steven-cdist at armstrong.cc)
# 2014 Daniel Heule (hda at sfs.biz)
#
# This file is part of cdist.
#
# cdist is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# cdist is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with cdist. If not, see <http://www.gnu.org/licenses/>.
#
#
import argparse
import logging
import os
import sys
import cdist
from cdist import core
class MissingRequiredEnvironmentVariableError(cdist.Error):
def __init__(self, name):
self.name = name
self.message = ("Emulator requires the environment variable %s to be "
"setup" % self.name)
def __str__(self):
return self.message
class DefaultList(list):
"""Helper class to allow default values for optional_multiple parameters.
@see https://groups.google.com/forum/#!msg/comp.lang.python/sAUvkJEDpRc/RnRymrzJVDYJ
"""
def __copy__(self):
return []
@classmethod
def create(cls, initial=None):
if initial:
return cls(initial.split('\n'))
class Emulator(object):
def __init__(self, argv, stdin=sys.stdin.buffer, env=os.environ):
self.argv = argv
self.stdin = stdin
self.env = env
self.object_id = ''
try:
self.global_path = self.env['__global']
self.target_host = (
self.env['__target_host'],
self.env['__target_hostname'],
self.env['__target_fqdn']
)
# Internal variables
self.object_source = self.env['__cdist_manifest']
self.type_base_path = self.env['__cdist_type_base_path']
self.object_marker = self.env['__cdist_object_marker']
except KeyError as e:
raise MissingRequiredEnvironmentVariableError(e.args[0])
self.object_base_path = os.path.join(self.global_path, "object")
self.typeorder_path = os.path.join(self.global_path, "typeorder")
self.type_name = os.path.basename(argv[0])
self.cdist_type = core.CdistType(self.type_base_path, self.type_name)
# If set then object alreay exists and this var holds existing
# requirements.
self._existing_reqs = None
self.__init_log()
def run(self):
"""Emulate type commands (i.e. __file and co)"""
self.commandline()
self.setup_object()
self.save_stdin()
self.record_requirements()
self.record_auto_requirements()
self.log.trace("Finished %s %s" % (
self.cdist_object.path, self.parameters))
def __init_log(self):
"""Setup logging facility"""
if '__cdist_loglevel' in self.env:
try:
level = int(self.env['__cdist_loglevel'])
except:
level = logging.WARNING
else:
level = logging.WARNING
logging.root.setLevel(level)
self.log = logging.getLogger(self.target_host[0])
def commandline(self):
"""Parse command line"""
parser = argparse.ArgumentParser(add_help=False,
argument_default=argparse.SUPPRESS)
for parameter in self.cdist_type.required_parameters:
argument = "--" + parameter
parser.add_argument(argument, dest=parameter, action='store',
required=True)
for parameter in self.cdist_type.required_multiple_parameters:
argument = "--" + parameter
parser.add_argument(argument, dest=parameter, action='append',
required=True)
for parameter in self.cdist_type.optional_parameters:
argument = "--" + parameter
default = self.cdist_type.parameter_defaults.get(parameter, None)
parser.add_argument(argument, dest=parameter, action='store',
required=False, default=default)
for parameter in self.cdist_type.optional_multiple_parameters:
argument = "--" + parameter
default = DefaultList.create(
self.cdist_type.parameter_defaults.get(
parameter, None))
parser.add_argument(argument, dest=parameter, action='append',
required=False, default=default)
for parameter in self.cdist_type.boolean_parameters:
argument = "--" + parameter
parser.add_argument(argument, dest=parameter,
action='store_const', const='')
# If not singleton support one positional parameter
if not self.cdist_type.is_singleton:
parser.add_argument("object_id", nargs=1)
# And finally parse/verify parameter
self.args = parser.parse_args(self.argv[1:])
self.log.trace('Args: %s' % self.args)
def setup_object(self):
# Setup object - and ensure it is not in args
if self.cdist_type.is_singleton:
self.object_id = ''
else:
self.object_id = self.args.object_id[0]
del self.args.object_id
# Instantiate the cdist object we are defining
self.cdist_object = core.CdistObject(
self.cdist_type, self.object_base_path, self.object_marker,
self.object_id)
# Create object with given parameters
self.parameters = {}
for key, value in vars(self.args).items():
if value is not None:
self.parameters[key] = value
if self.cdist_object.exists and 'CDIST_OVERRIDE' not in self.env:
# Make existing requirements a set so that we can compare it
# later with new requirements.
self._existing_reqs = set(self.cdist_object.requirements)
if self.cdist_object.parameters != self.parameters:
errmsg = ("Object %s already exists with conflicting "
"parameters:\n%s: %s\n%s: %s" % (
self.cdist_object.name,
" ".join(self.cdist_object.source),
self.cdist_object.parameters,
self.object_source,
self.parameters))
self.log.error(errmsg)
raise cdist.Error(errmsg)
else:
if self.cdist_object.exists:
self.log.debug(('Object %s override forced with '
'CDIST_OVERRIDE'), self.cdist_object.name)
self.cdist_object.create(True)
else:
self.cdist_object.create()
self.cdist_object.parameters = self.parameters
# record the created object in typeorder file
with open(self.typeorder_path, 'a') as typeorderfile:
print(self.cdist_object.name, file=typeorderfile)
# Record / Append source
self.cdist_object.source.append(self.object_source)
chunk_size = 65536
def _read_stdin(self):
return self.stdin.read(self.chunk_size)
def save_stdin(self):
"""If something is written to stdin, save it in the object as
$__object/stdin so it can be accessed in manifest and gencode-*
scripts.
"""
if not self.stdin.isatty():
try:
# go directly to file instead of using CdistObject's api
# as that does not support streaming
path = os.path.join(self.cdist_object.absolute_path, 'stdin')
with open(path, 'wb') as fd:
chunk = self._read_stdin()
while chunk:
fd.write(chunk)
chunk = self._read_stdin()
except EnvironmentError as e:
raise cdist.Error('Failed to read from stdin: %s' % e)
def record_requirement(self, requirement):
"""record requirement and return recorded requirement"""
# Raises an error, if object cannot be created
try:
cdist_object = self.cdist_object.object_from_name(requirement)
except core.cdist_type.NoSuchTypeError as e:
self.log.error(("%s requires object %s, but type %s does not"
" exist. Defined at %s" % (
self.cdist_object.name,
requirement, e.name, self.object_source)))
raise
except core.cdist_object.MissingObjectIdError as e:
self.log.error(("%s requires object %s without object id."
" Defined at %s" % (self.cdist_object.name,
requirement,
self.object_source)))
raise
self.log.debug("Recording requirement: %s", requirement)
# Save the sanitised version, not the user supplied one
# (__file//bar => __file/bar)
# This ensures pattern matching is done against sanitised list
self.cdist_object.requirements.append(cdist_object.name)
return cdist_object.name
def record_requirements(self):
"""Record requirements."""
# Inject the predecessor, but not if its an override
# (this would leed to an circular dependency)
if ("CDIST_ORDER_DEPENDENCY" in self.env and
'CDIST_OVERRIDE' not in self.env):
# load object name created befor this one from typeorder file ...
with open(self.typeorder_path, 'r') as typecreationfile:
typecreationorder = typecreationfile.readlines()
# get the type created before this one ...
try:
lastcreatedtype = typecreationorder[-2].strip()
if 'require' in self.env:
self.env['require'] += " " + lastcreatedtype
else:
self.env['require'] = lastcreatedtype
self.log.debug(("Injecting require for "
"CDIST_ORDER_DEPENDENCY: %s for %s"),
lastcreatedtype, self.cdist_object.name)
except IndexError:
# if no second last line, we are on the first type,
# so do not set a requirement
pass
reqs = set()
if "require" in self.env:
requirements = self.env['require']
self.log.debug("reqs = " + requirements)
for requirement in requirements.split(" "):
# Ignore empty fields - probably the only field anyway
if len(requirement) == 0:
continue
object_name = self.record_requirement(requirement)
reqs.add(object_name)
if self._existing_reqs is not None:
# If object exists then compare existing and new requirements.
if self._existing_reqs != reqs:
warnmsg = ("Object {} already exists with requirements:\n"
"{}: {}\n"
"{}: {}\n"
"Dependency resolver could not handle dependencies "
"as expected.".format(
self.cdist_object.name,
" ".join(self.cdist_object.source),
self._existing_reqs,
self.object_source,
reqs
))
self.log.warning(warnmsg)
def record_auto_requirements(self):
"""An object shall automatically depend on all objects that it
defined in it's type manifest.
"""
# __object_name is the name of the object whose type manifest is
# currently executed
__object_name = self.env.get('__object_name', None)
if __object_name:
# The object whose type manifest is currently run
parent = self.cdist_object.object_from_name(__object_name)
# The object currently being defined
current_object = self.cdist_object
# As parent defined current_object it shall automatically
# depend on it.
# But only if the user hasn't said otherwise.
# Must prevent circular dependencies.
if parent.name not in current_object.requirements:
parent.autorequire.append(current_object.name)