# Copyright (C) 2012 Canonical Ltd.
# Copyright (C) 2012, 2013 Hewlett-Packard Development Company, L.P.
# Copyright (C) 2012 Yahoo! Inc.
#
# Author: Scott Moser <scott.moser@canonical.com>
# Author: Juerg Haefliger <juerg.haefliger@hp.com>
# Author: Joshua Harlow <harlowja@yahoo-inc.com>
#
# This file is part of cloud-init. See LICENSE file for license information.
from time import time
import contextlib
import os
from configparser import NoSectionError, NoOptionError, RawConfigParser
from io import StringIO
from cloudinit.settings import (PER_INSTANCE, PER_ALWAYS, PER_ONCE,
CFG_ENV_NAME)
from cloudinit import log as logging
from cloudinit import type_utils
from cloudinit import util
LOG = logging.getLogger(__name__)
class LockFailure(Exception):
pass
class DummyLock(object):
pass
class DummySemaphores(object):
def __init__(self):
pass
@contextlib.contextmanager
def lock(self, _name, _freq, _clear_on_fail=False):
yield DummyLock()
def has_run(self, _name, _freq):
return False
def clear(self, _name, _freq):
return True
def clear_all(self):
pass
class FileLock(object):
def __init__(self, fn):
self.fn = fn
def __str__(self):
return "<%s using file %r>" % (type_utils.obj_name(self), self.fn)
def canon_sem_name(name):
return name.replace("-", "_")
class FileSemaphores(object):
def __init__(self, sem_path):
self.sem_path = sem_path
@contextlib.contextmanager
def lock(self, name, freq, clear_on_fail=False):
name = canon_sem_name(name)
try:
yield self._acquire(name, freq)
except Exception:
if clear_on_fail:
self.clear(name, freq)
raise
def clear(self, name, freq):
name = canon_sem_name(name)
sem_file = self._get_path(name, freq)
try:
util.del_file(sem_file)
except (IOError, OSError):
util.logexc(LOG, "Failed deleting semaphore %s", sem_file)
return False
return True
def clear_all(self):
try:
util.del_dir(self.sem_path)
except (IOError, OSError):
util.logexc(LOG, "Failed deleting semaphore directory %s",
self.sem_path)
def _acquire(self, name, freq):
# Check again if its been already gotten
if self.has_run(name, freq):
return None
# This is a race condition since nothing atomic is happening
# here, but this should be ok due to the nature of when
# and where cloud-init runs... (file writing is not a lock...)
sem_file = self._get_path(name, freq)
contents = "%s: %s\n" % (os.getpid(), time())
try:
util.write_file(sem_file, contents)
except (IOError, OSError):
util.logexc(LOG, "Failed writing semaphore file %s", sem_file)
return None
return FileLock(sem_file)
def has_run(self, name, freq):
if not freq or freq == PER_ALWAYS:
return False
cname = canon_sem_name(name)
sem_file = self._get_path(cname, freq)
# This isn't really a good atomic check
# but it suffices for where and when cloudinit runs
if os.path.exists(sem_file):
return True
# this case could happen if the migrator module hadn't run yet
# but the item had run before we did canon_sem_name.
if cname != name and os.path.exists(self._get_path(name, freq)):
LOG.warning("%s has run without canonicalized name [%s].\n"
"likely the migrator has not yet run. "
"It will run next boot.\n"
"run manually with: cloud-init single --name=migrator",
name, cname)
return True
return False
def _get_path(self, name, freq):
sem_path = self.sem_path
if not freq or freq == PER_INSTANCE:
return os.path.join(sem_path, name)
else:
return os.path.join(sem_path, "%s.%s" % (name, freq))
class Runners(object):
def __init__(self, paths):
self.paths = paths
self.sems = {}
def _get_sem(self, freq):
if freq == PER_ALWAYS or not freq:
return None
sem_path = None
if freq == PER_INSTANCE:
# This may not exist,
# so thats why we still check for none
# below if say the paths object
# doesn't have a datasource that can
# provide this instance path...
sem_path = self.paths.get_ipath("sem")
elif freq == PER_ONCE:
sem_path = self.paths.get_cpath("sem")
if not sem_path:
return None
if sem_path not in self.sems:
self.sems[sem_path] = FileSemaphores(sem_path)
return self.sems[sem_path]
def run(self, name, functor, args, freq=None, clear_on_fail=False):
sem = self._get_sem(freq)
if not sem:
sem = DummySemaphores()
if not args:
args = []
if sem.has_run(name, freq):
LOG.debug("%s already ran (freq=%s)", name, freq)
return (False, None)
with sem.lock(name, freq, clear_on_fail) as lk:
if not lk:
raise LockFailure("Failed to acquire lock for %s" % name)
else:
LOG.debug("Running %s using lock (%s)", name, lk)
if isinstance(args, (dict)):
results = functor(**args)
else:
results = functor(*args)
return (True, results)
class ConfigMerger(object):
def __init__(self, paths=None, datasource=None,
additional_fns=None, base_cfg=None,
include_vendor=True):
self._paths = paths
self._ds = datasource
self._fns = additional_fns
self._base_cfg = base_cfg
self._include_vendor = include_vendor
# Created on first use
self._cfg = None
def _get_datasource_configs(self):
d_cfgs = []
if self._ds:
try:
ds_cfg = self._ds.get_config_obj()
if ds_cfg and isinstance(ds_cfg, (dict)):
d_cfgs.append(ds_cfg)
except Exception:
util.logexc(LOG, "Failed loading of datasource config object "
"from %s", self._ds)
return d_cfgs
def _get_env_configs(self):
e_cfgs = []
if CFG_ENV_NAME in os.environ:
e_fn = os.environ[CFG_ENV_NAME]
try:
e_cfgs.append(util.read_conf(e_fn))
except Exception:
util.logexc(LOG, 'Failed loading of env. config from %s',
e_fn)
return e_cfgs
def _get_instance_configs(self):
i_cfgs = []
# If cloud-config was written, pick it up as
# a configuration file to use when running...
if not self._paths:
return i_cfgs
cc_paths = ['cloud_config']
if self._include_vendor:
cc_paths.append('vendor_cloud_config')
for cc_p in cc_paths:
cc_fn = self._paths.get_ipath_cur(cc_p)
if cc_fn and os.path.isfile(cc_fn):
try:
i_cfgs.append(util.read_conf(cc_fn))
except PermissionError:
LOG.debug(
'Skipped loading cloud-config from %s due to'
' non-root.', cc_fn)
except Exception:
util.logexc(LOG, 'Failed loading of cloud-config from %s',
cc_fn)
return i_cfgs
def _read_cfg(self):
# Input config files override
# env config files which
# override instance configs
# which override datasource
# configs which override
# base configuration
cfgs = []
if self._fns:
for c_fn in self._fns:
try:
cfgs.append(util.read_conf(c_fn))
except Exception:
util.logexc(LOG, "Failed loading of configuration from %s",
c_fn)
cfgs.extend(self._get_env_configs())
cfgs.extend(self._get_instance_configs())
cfgs.extend(self._get_datasource_configs())
if self._base_cfg:
cfgs.append(self._base_cfg)
return util.mergemanydict(cfgs)
@property
def cfg(self):
# None check to avoid empty case causing re-reading
if self._cfg is None:
self._cfg = self._read_cfg()
return self._cfg
class ContentHandlers(object):
def __init__(self):
self.registered = {}
self.initialized = []
def __contains__(self, item):
return self.is_registered(item)
def __getitem__(self, key):
return self._get_handler(key)
def is_registered(self, content_type):
return content_type in self.registered
def register(self, mod, initialized=False, overwrite=True):
types = set()
for t in mod.list_types():
if overwrite:
types.add(t)
else:
if not self.is_registered(t):
types.add(t)
for t in types:
self.registered[t] = mod
if initialized and mod not in self.initialized:
self.initialized.append(mod)
return types
def _get_handler(self, content_type):
return self.registered[content_type]
def items(self):
return list(self.registered.items())
class Paths(object):
def __init__(self, path_cfgs, ds=None):
self.cfgs = path_cfgs
# Populate all the initial paths
self.cloud_dir = path_cfgs.get('cloud_dir', '/var/lib/cloud')
self.run_dir = path_cfgs.get('run_dir', '/run/cloud-init')
self.instance_link = os.path.join(self.cloud_dir, 'instance')
self.boot_finished = os.path.join(self.instance_link, "boot-finished")
self.upstart_conf_d = path_cfgs.get('upstart_dir')
self.seed_dir = os.path.join(self.cloud_dir, 'seed')
# This one isn't joined, since it should just be read-only
template_dir = path_cfgs.get('templates_dir', '/etc/cloud/templates/')
self.template_tpl = os.path.join(template_dir, '%s.tmpl')
self.lookups = {
"handlers": "handlers",
"scripts": "scripts",
"vendor_scripts": "scripts/vendor",
"sem": "sem",
"boothooks": "boothooks",
"userdata_raw": "user-data.txt",
"userdata": "user-data.txt.i",
"obj_pkl": "obj.pkl",
"cloud_config": "cloud-config.txt",
"vendor_cloud_config": "vendor-cloud-config.txt",
"data": "data",
"vendordata_raw": "vendor-data.txt",
"vendordata": "vendor-data.txt.i",
"instance_id": ".instance-id",
"manual_clean_marker": "manual-clean",
"warnings": "warnings",
}
# Set when a datasource becomes active
self.datasource = ds
# get_ipath_cur: get the current instance path for an item
def get_ipath_cur(self, name=None):
return self._get_path(self.instance_link, name)
# get_cpath : get the "clouddir" (/var/lib/cloud/<name>)
# for a name in dirmap
def get_cpath(self, name=None):
return self._get_path(self.cloud_dir, name)
# _get_ipath : get the instance path for a name in pathmap
# (/var/lib/cloud/instances/<instance>/<name>)
def _get_ipath(self, name=None):
if not self.datasource:
return None
iid = self.datasource.get_instance_id()
if iid is None:
return None
path_safe_iid = str(iid).replace(os.sep, '_')
ipath = os.path.join(self.cloud_dir, 'instances', path_safe_iid)
add_on = self.lookups.get(name)
if add_on:
ipath = os.path.join(ipath, add_on)
return ipath
# get_ipath : get the instance path for a name in pathmap
# (/var/lib/cloud/instances/<instance>/<name>)
# returns None + warns if no active datasource....
def get_ipath(self, name=None):
ipath = self._get_ipath(name)
if not ipath:
LOG.warning(("No per instance data available, "
"is there an datasource/iid set?"))
return None
else:
return ipath
def _get_path(self, base, name=None):
if name is None:
return base
return os.path.join(base, self.lookups[name])
def get_runpath(self, name=None):
return self._get_path(self.run_dir, name)
# This config parser will not throw when sections don't exist
# and you are setting values on those sections which is useful
# when writing to new options that may not have corresponding
# sections. Also it can default other values when doing gets
# so that if those sections/options do not exist you will
# get a default instead of an error. Another useful case where
# you can avoid catching exceptions that you typically don't
# care about...
class DefaultingConfigParser(RawConfigParser):
DEF_INT = 0
DEF_FLOAT = 0.0
DEF_BOOLEAN = False
DEF_BASE = None
def get(self, section, option):
value = self.DEF_BASE
try:
value = RawConfigParser.get(self, section, option)
except NoSectionError:
pass
except NoOptionError:
pass
return value
def set(self, section, option, value=None):
if not self.has_section(section) and section.lower() != 'default':
self.add_section(section)
RawConfigParser.set(self, section, option, value)
def remove_option(self, section, option):
if self.has_option(section, option):
RawConfigParser.remove_option(self, section, option)
def getboolean(self, section, option):
if not self.has_option(section, option):
return self.DEF_BOOLEAN
return RawConfigParser.getboolean(self, section, option)
def getfloat(self, section, option):
if not self.has_option(section, option):
return self.DEF_FLOAT
return RawConfigParser.getfloat(self, section, option)
def getint(self, section, option):
if not self.has_option(section, option):
return self.DEF_INT
return RawConfigParser.getint(self, section, option)
def stringify(self, header=None):
contents = ''
outputstream = StringIO()
self.write(outputstream)
outputstream.flush()
contents = outputstream.getvalue()
if header:
contents = '\n'.join([header, contents, ''])
return contents
# vi: ts=4 expandtab