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Diffstat (limited to 'charms/trusty/ceilometer/charmhelpers/core/host.py')
| -rw-r--r-- | charms/trusty/ceilometer/charmhelpers/core/host.py | 714 |
1 files changed, 714 insertions, 0 deletions
diff --git a/charms/trusty/ceilometer/charmhelpers/core/host.py b/charms/trusty/ceilometer/charmhelpers/core/host.py new file mode 100644 index 0000000..64b2df5 --- /dev/null +++ b/charms/trusty/ceilometer/charmhelpers/core/host.py @@ -0,0 +1,714 @@ +# Copyright 2014-2015 Canonical Limited. +# +# This file is part of charm-helpers. +# +# charm-helpers is free software: you can redistribute it and/or modify +# it under the terms of the GNU Lesser General Public License version 3 as +# published by the Free Software Foundation. +# +# charm-helpers 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 Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public License +# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>. + +"""Tools for working with the host system""" +# Copyright 2012 Canonical Ltd. +# +# Authors: +# Nick Moffitt <nick.moffitt@canonical.com> +# Matthew Wedgwood <matthew.wedgwood@canonical.com> + +import os +import re +import pwd +import glob +import grp +import random +import string +import subprocess +import hashlib +import functools +import itertools +from contextlib import contextmanager +from collections import OrderedDict + +import six + +from .hookenv import log +from .fstab import Fstab + + +def service_start(service_name): + """Start a system service""" + return service('start', service_name) + + +def service_stop(service_name): + """Stop a system service""" + return service('stop', service_name) + + +def service_restart(service_name): + """Restart a system service""" + return service('restart', service_name) + + +def service_reload(service_name, restart_on_failure=False): + """Reload a system service, optionally falling back to restart if + reload fails""" + service_result = service('reload', service_name) + if not service_result and restart_on_failure: + service_result = service('restart', service_name) + return service_result + + +def service_pause(service_name, init_dir="/etc/init", initd_dir="/etc/init.d"): + """Pause a system service. + + Stop it, and prevent it from starting again at boot.""" + stopped = True + if service_running(service_name): + stopped = service_stop(service_name) + upstart_file = os.path.join(init_dir, "{}.conf".format(service_name)) + sysv_file = os.path.join(initd_dir, service_name) + if init_is_systemd(): + service('disable', service_name) + elif os.path.exists(upstart_file): + override_path = os.path.join( + init_dir, '{}.override'.format(service_name)) + with open(override_path, 'w') as fh: + fh.write("manual\n") + elif os.path.exists(sysv_file): + subprocess.check_call(["update-rc.d", service_name, "disable"]) + else: + raise ValueError( + "Unable to detect {0} as SystemD, Upstart {1} or" + " SysV {2}".format( + service_name, upstart_file, sysv_file)) + return stopped + + +def service_resume(service_name, init_dir="/etc/init", + initd_dir="/etc/init.d"): + """Resume a system service. + + Reenable starting again at boot. Start the service""" + upstart_file = os.path.join(init_dir, "{}.conf".format(service_name)) + sysv_file = os.path.join(initd_dir, service_name) + if init_is_systemd(): + service('enable', service_name) + elif os.path.exists(upstart_file): + override_path = os.path.join( + init_dir, '{}.override'.format(service_name)) + if os.path.exists(override_path): + os.unlink(override_path) + elif os.path.exists(sysv_file): + subprocess.check_call(["update-rc.d", service_name, "enable"]) + else: + raise ValueError( + "Unable to detect {0} as SystemD, Upstart {1} or" + " SysV {2}".format( + service_name, upstart_file, sysv_file)) + + started = service_running(service_name) + if not started: + started = service_start(service_name) + return started + + +def service(action, service_name): + """Control a system service""" + if init_is_systemd(): + cmd = ['systemctl', action, service_name] + else: + cmd = ['service', service_name, action] + return subprocess.call(cmd) == 0 + + +_UPSTART_CONF = "/etc/init/{}.conf" +_INIT_D_CONF = "/etc/init.d/{}" + + +def service_running(service_name): + """Determine whether a system service is running""" + if init_is_systemd(): + return service('is-active', service_name) + else: + if os.path.exists(_UPSTART_CONF.format(service_name)): + try: + output = subprocess.check_output( + ['status', service_name], + stderr=subprocess.STDOUT).decode('UTF-8') + except subprocess.CalledProcessError: + return False + else: + # This works for upstart scripts where the 'service' command + # returns a consistent string to represent running 'start/running' + if "start/running" in output: + return True + elif os.path.exists(_INIT_D_CONF.format(service_name)): + # Check System V scripts init script return codes + return service('status', service_name) + return False + + +def service_available(service_name): + """Determine whether a system service is available""" + try: + subprocess.check_output( + ['service', service_name, 'status'], + stderr=subprocess.STDOUT).decode('UTF-8') + except subprocess.CalledProcessError as e: + return b'unrecognized service' not in e.output + else: + return True + + +SYSTEMD_SYSTEM = '/run/systemd/system' + + +def init_is_systemd(): + """Return True if the host system uses systemd, False otherwise.""" + return os.path.isdir(SYSTEMD_SYSTEM) + + +def adduser(username, password=None, shell='/bin/bash', system_user=False, + primary_group=None, secondary_groups=None): + """Add a user to the system. + + Will log but otherwise succeed if the user already exists. + + :param str username: Username to create + :param str password: Password for user; if ``None``, create a system user + :param str shell: The default shell for the user + :param bool system_user: Whether to create a login or system user + :param str primary_group: Primary group for user; defaults to username + :param list secondary_groups: Optional list of additional groups + + :returns: The password database entry struct, as returned by `pwd.getpwnam` + """ + try: + user_info = pwd.getpwnam(username) + log('user {0} already exists!'.format(username)) + except KeyError: + log('creating user {0}'.format(username)) + cmd = ['useradd'] + if system_user or password is None: + cmd.append('--system') + else: + cmd.extend([ + '--create-home', + '--shell', shell, + '--password', password, + ]) + if not primary_group: + try: + grp.getgrnam(username) + primary_group = username # avoid "group exists" error + except KeyError: + pass + if primary_group: + cmd.extend(['-g', primary_group]) + if secondary_groups: + cmd.extend(['-G', ','.join(secondary_groups)]) + cmd.append(username) + subprocess.check_call(cmd) + user_info = pwd.getpwnam(username) + return user_info + + +def user_exists(username): + """Check if a user exists""" + try: + pwd.getpwnam(username) + user_exists = True + except KeyError: + user_exists = False + return user_exists + + +def add_group(group_name, system_group=False): + """Add a group to the system""" + try: + group_info = grp.getgrnam(group_name) + log('group {0} already exists!'.format(group_name)) + except KeyError: + log('creating group {0}'.format(group_name)) + cmd = ['addgroup'] + if system_group: + cmd.append('--system') + else: + cmd.extend([ + '--group', + ]) + cmd.append(group_name) + subprocess.check_call(cmd) + group_info = grp.getgrnam(group_name) + return group_info + + +def add_user_to_group(username, group): + """Add a user to a group""" + cmd = ['gpasswd', '-a', username, group] + log("Adding user {} to group {}".format(username, group)) + subprocess.check_call(cmd) + + +def rsync(from_path, to_path, flags='-r', options=None): + """Replicate the contents of a path""" + options = options or ['--delete', '--executability'] + cmd = ['/usr/bin/rsync', flags] + cmd.extend(options) + cmd.append(from_path) + cmd.append(to_path) + log(" ".join(cmd)) + return subprocess.check_output(cmd).decode('UTF-8').strip() + + +def symlink(source, destination): + """Create a symbolic link""" + log("Symlinking {} as {}".format(source, destination)) + cmd = [ + 'ln', + '-sf', + source, + destination, + ] + subprocess.check_call(cmd) + + +def mkdir(path, owner='root', group='root', perms=0o555, force=False): + """Create a directory""" + log("Making dir {} {}:{} {:o}".format(path, owner, group, + perms)) + uid = pwd.getpwnam(owner).pw_uid + gid = grp.getgrnam(group).gr_gid + realpath = os.path.abspath(path) + path_exists = os.path.exists(realpath) + if path_exists and force: + if not os.path.isdir(realpath): + log("Removing non-directory file {} prior to mkdir()".format(path)) + os.unlink(realpath) + os.makedirs(realpath, perms) + elif not path_exists: + os.makedirs(realpath, perms) + os.chown(realpath, uid, gid) + os.chmod(realpath, perms) + + +def write_file(path, content, owner='root', group='root', perms=0o444): + """Create or overwrite a file with the contents of a byte string.""" + log("Writing file {} {}:{} {:o}".format(path, owner, group, perms)) + uid = pwd.getpwnam(owner).pw_uid + gid = grp.getgrnam(group).gr_gid + with open(path, 'wb') as target: + os.fchown(target.fileno(), uid, gid) + os.fchmod(target.fileno(), perms) + target.write(content) + + +def fstab_remove(mp): + """Remove the given mountpoint entry from /etc/fstab""" + return Fstab.remove_by_mountpoint(mp) + + +def fstab_add(dev, mp, fs, options=None): + """Adds the given device entry to the /etc/fstab file""" + return Fstab.add(dev, mp, fs, options=options) + + +def mount(device, mountpoint, options=None, persist=False, filesystem="ext3"): + """Mount a filesystem at a particular mountpoint""" + cmd_args = ['mount'] + if options is not None: + cmd_args.extend(['-o', options]) + cmd_args.extend([device, mountpoint]) + try: + subprocess.check_output(cmd_args) + except subprocess.CalledProcessError as e: + log('Error mounting {} at {}\n{}'.format(device, mountpoint, e.output)) + return False + + if persist: + return fstab_add(device, mountpoint, filesystem, options=options) + return True + + +def umount(mountpoint, persist=False): + """Unmount a filesystem""" + cmd_args = ['umount', mountpoint] + try: + subprocess.check_output(cmd_args) + except subprocess.CalledProcessError as e: + log('Error unmounting {}\n{}'.format(mountpoint, e.output)) + return False + + if persist: + return fstab_remove(mountpoint) + return True + + +def mounts(): + """Get a list of all mounted volumes as [[mountpoint,device],[...]]""" + with open('/proc/mounts') as f: + # [['/mount/point','/dev/path'],[...]] + system_mounts = [m[1::-1] for m in [l.strip().split() + for l in f.readlines()]] + return system_mounts + + +def fstab_mount(mountpoint): + """Mount filesystem using fstab""" + cmd_args = ['mount', mountpoint] + try: + subprocess.check_output(cmd_args) + except subprocess.CalledProcessError as e: + log('Error unmounting {}\n{}'.format(mountpoint, e.output)) + return False + return True + + +def file_hash(path, hash_type='md5'): + """Generate a hash checksum of the contents of 'path' or None if not found. + + :param str hash_type: Any hash alrgorithm supported by :mod:`hashlib`, + such as md5, sha1, sha256, sha512, etc. + """ + if os.path.exists(path): + h = getattr(hashlib, hash_type)() + with open(path, 'rb') as source: + h.update(source.read()) + return h.hexdigest() + else: + return None + + +def path_hash(path): + """Generate a hash checksum of all files matching 'path'. Standard + wildcards like '*' and '?' are supported, see documentation for the 'glob' + module for more information. + + :return: dict: A { filename: hash } dictionary for all matched files. + Empty if none found. + """ + return { + filename: file_hash(filename) + for filename in glob.iglob(path) + } + + +def check_hash(path, checksum, hash_type='md5'): + """Validate a file using a cryptographic checksum. + + :param str checksum: Value of the checksum used to validate the file. + :param str hash_type: Hash algorithm used to generate `checksum`. + Can be any hash alrgorithm supported by :mod:`hashlib`, + such as md5, sha1, sha256, sha512, etc. + :raises ChecksumError: If the file fails the checksum + + """ + actual_checksum = file_hash(path, hash_type) + if checksum != actual_checksum: + raise ChecksumError("'%s' != '%s'" % (checksum, actual_checksum)) + + +class ChecksumError(ValueError): + """A class derived from Value error to indicate the checksum failed.""" + pass + + +def restart_on_change(restart_map, stopstart=False, restart_functions=None): + """Restart services based on configuration files changing + + This function is used a decorator, for example:: + + @restart_on_change({ + '/etc/ceph/ceph.conf': [ 'cinder-api', 'cinder-volume' ] + '/etc/apache/sites-enabled/*': [ 'apache2' ] + }) + def config_changed(): + pass # your code here + + In this example, the cinder-api and cinder-volume services + would be restarted if /etc/ceph/ceph.conf is changed by the + ceph_client_changed function. The apache2 service would be + restarted if any file matching the pattern got changed, created + or removed. Standard wildcards are supported, see documentation + for the 'glob' module for more information. + + @param restart_map: {path_file_name: [service_name, ...] + @param stopstart: DEFAULT false; whether to stop, start OR restart + @param restart_functions: nonstandard functions to use to restart services + {svc: func, ...} + @returns result from decorated function + """ + def wrap(f): + @functools.wraps(f) + def wrapped_f(*args, **kwargs): + return restart_on_change_helper( + (lambda: f(*args, **kwargs)), restart_map, stopstart, + restart_functions) + return wrapped_f + return wrap + + +def restart_on_change_helper(lambda_f, restart_map, stopstart=False, + restart_functions=None): + """Helper function to perform the restart_on_change function. + + This is provided for decorators to restart services if files described + in the restart_map have changed after an invocation of lambda_f(). + + @param lambda_f: function to call. + @param restart_map: {file: [service, ...]} + @param stopstart: whether to stop, start or restart a service + @param restart_functions: nonstandard functions to use to restart services + {svc: func, ...} + @returns result of lambda_f() + """ + if restart_functions is None: + restart_functions = {} + checksums = {path: path_hash(path) for path in restart_map} + r = lambda_f() + # create a list of lists of the services to restart + restarts = [restart_map[path] + for path in restart_map + if path_hash(path) != checksums[path]] + # create a flat list of ordered services without duplicates from lists + services_list = list(OrderedDict.fromkeys(itertools.chain(*restarts))) + if services_list: + actions = ('stop', 'start') if stopstart else ('restart',) + for service_name in services_list: + if service_name in restart_functions: + restart_functions[service_name](service_name) + else: + for action in actions: + service(action, service_name) + return r + + +def lsb_release(): + """Return /etc/lsb-release in a dict""" + d = {} + with open('/etc/lsb-release', 'r') as lsb: + for l in lsb: + k, v = l.split('=') + d[k.strip()] = v.strip() + return d + + +def pwgen(length=None): + """Generate a random pasword.""" + if length is None: + # A random length is ok to use a weak PRNG + length = random.choice(range(35, 45)) + alphanumeric_chars = [ + l for l in (string.ascii_letters + string.digits) + if l not in 'l0QD1vAEIOUaeiou'] + # Use a crypto-friendly PRNG (e.g. /dev/urandom) for making the + # actual password + random_generator = random.SystemRandom() + random_chars = [ + random_generator.choice(alphanumeric_chars) for _ in range(length)] + return(''.join(random_chars)) + + +def is_phy_iface(interface): + """Returns True if interface is not virtual, otherwise False.""" + if interface: + sys_net = '/sys/class/net' + if os.path.isdir(sys_net): + for iface in glob.glob(os.path.join(sys_net, '*')): + if '/virtual/' in os.path.realpath(iface): + continue + + if interface == os.path.basename(iface): + return True + + return False + + +def get_bond_master(interface): + """Returns bond master if interface is bond slave otherwise None. + + NOTE: the provided interface is expected to be physical + """ + if interface: + iface_path = '/sys/class/net/%s' % (interface) + if os.path.exists(iface_path): + if '/virtual/' in os.path.realpath(iface_path): + return None + + master = os.path.join(iface_path, 'master') + if os.path.exists(master): + master = os.path.realpath(master) + # make sure it is a bond master + if os.path.exists(os.path.join(master, 'bonding')): + return os.path.basename(master) + + return None + + +def list_nics(nic_type=None): + """Return a list of nics of given type(s)""" + if isinstance(nic_type, six.string_types): + int_types = [nic_type] + else: + int_types = nic_type + + interfaces = [] + if nic_type: + for int_type in int_types: + cmd = ['ip', 'addr', 'show', 'label', int_type + '*'] + ip_output = subprocess.check_output(cmd).decode('UTF-8') + ip_output = ip_output.split('\n') + ip_output = (line for line in ip_output if line) + for line in ip_output: + if line.split()[1].startswith(int_type): + matched = re.search('.*: (' + int_type + + r'[0-9]+\.[0-9]+)@.*', line) + if matched: + iface = matched.groups()[0] + else: + iface = line.split()[1].replace(":", "") + + if iface not in interfaces: + interfaces.append(iface) + else: + cmd = ['ip', 'a'] + ip_output = subprocess.check_output(cmd).decode('UTF-8').split('\n') + ip_output = (line.strip() for line in ip_output if line) + + key = re.compile('^[0-9]+:\s+(.+):') + for line in ip_output: + matched = re.search(key, line) + if matched: + iface = matched.group(1) + iface = iface.partition("@")[0] + if iface not in interfaces: + interfaces.append(iface) + + return interfaces + + +def set_nic_mtu(nic, mtu): + """Set the Maximum Transmission Unit (MTU) on a network interface.""" + cmd = ['ip', 'link', 'set', nic, 'mtu', mtu] + subprocess.check_call(cmd) + + +def get_nic_mtu(nic): + """Return the Maximum Transmission Unit (MTU) for a network interface.""" + cmd = ['ip', 'addr', 'show', nic] + ip_output = subprocess.check_output(cmd).decode('UTF-8').split('\n') + mtu = "" + for line in ip_output: + words = line.split() + if 'mtu' in words: + mtu = words[words.index("mtu") + 1] + return mtu + + +def get_nic_hwaddr(nic): + """Return the Media Access Control (MAC) for a network interface.""" + cmd = ['ip', '-o', '-0', 'addr', 'show', nic] + ip_output = subprocess.check_output(cmd).decode('UTF-8') + hwaddr = "" + words = ip_output.split() + if 'link/ether' in words: + hwaddr = words[words.index('link/ether') + 1] + return hwaddr + + +def cmp_pkgrevno(package, revno, pkgcache=None): + """Compare supplied revno with the revno of the installed package + + * 1 => Installed revno is greater than supplied arg + * 0 => Installed revno is the same as supplied arg + * -1 => Installed revno is less than supplied arg + + This function imports apt_cache function from charmhelpers.fetch if + the pkgcache argument is None. Be sure to add charmhelpers.fetch if + you call this function, or pass an apt_pkg.Cache() instance. + """ + import apt_pkg + if not pkgcache: + from charmhelpers.fetch import apt_cache + pkgcache = apt_cache() + pkg = pkgcache[package] + return apt_pkg.version_compare(pkg.current_ver.ver_str, revno) + + +@contextmanager +def chdir(directory): + """Change the current working directory to a different directory for a code + block and return the previous directory after the block exits. Useful to + run commands from a specificed directory. + + :param str directory: The directory path to change to for this context. + """ + cur = os.getcwd() + try: + yield os.chdir(directory) + finally: + os.chdir(cur) + + +def chownr(path, owner, group, follow_links=True, chowntopdir=False): + """Recursively change user and group ownership of files and directories + in given path. Doesn't chown path itself by default, only its children. + + :param str path: The string path to start changing ownership. + :param str owner: The owner string to use when looking up the uid. + :param str group: The group string to use when looking up the gid. + :param bool follow_links: Also Chown links if True + :param bool chowntopdir: Also chown path itself if True + """ + uid = pwd.getpwnam(owner).pw_uid + gid = grp.getgrnam(group).gr_gid + if follow_links: + chown = os.chown + else: + chown = os.lchown + + if chowntopdir: + broken_symlink = os.path.lexists(path) and not os.path.exists(path) + if not broken_symlink: + chown(path, uid, gid) + for root, dirs, files in os.walk(path): + for name in dirs + files: + full = os.path.join(root, name) + broken_symlink = os.path.lexists(full) and not os.path.exists(full) + if not broken_symlink: + chown(full, uid, gid) + + +def lchownr(path, owner, group): + """Recursively change user and group ownership of files and directories + in a given path, not following symbolic links. See the documentation for + 'os.lchown' for more information. + + :param str path: The string path to start changing ownership. + :param str owner: The owner string to use when looking up the uid. + :param str group: The group string to use when looking up the gid. + """ + chownr(path, owner, group, follow_links=False) + + +def get_total_ram(): + """The total amount of system RAM in bytes. + + This is what is reported by the OS, and may be overcommitted when + there are multiple containers hosted on the same machine. + """ + with open('/proc/meminfo', 'r') as f: + for line in f.readlines(): + if line: + key, value, unit = line.split() + if key == 'MemTotal:': + assert unit == 'kB', 'Unknown unit' + return int(value) * 1024 # Classic, not KiB. + raise NotImplementedError() |