Sync charm-helpers for Stein release

As a part of the Stein release, we need to ensure
that charmhelpers is up to date.

Change-Id: I53f388a0371b09bacd10122351f060a5a131947b

charmhelpers/contrib/storage/linux/utils.py

@@ -17,12 +17,53 @@ import re
 from stat import S_ISBLK
 
 from subprocess import (
+    CalledProcessError,
     check_call,
     check_output,
     call
 )
 
 
+def _luks_uuid(dev):
+    """
+    Check to see if dev is a LUKS encrypted volume, returning the UUID
+    of volume if it is.
+
+    :param: dev: path to block device to check.
+    :returns: str. UUID of LUKS device or None if not a LUKS device
+    """
+    try:
+        cmd = ['cryptsetup', 'luksUUID', dev]
+        return check_output(cmd).decode('UTF-8').strip()
+    except CalledProcessError:
+        return None
+
+
+def is_luks_device(dev):
+    """
+    Determine if dev is a LUKS-formatted block device.
+
+    :param: dev: A full path to a block device to check for LUKS header
+    presence
+    :returns: boolean: indicates whether a device is used based on LUKS header.
+    """
+    return True if _luks_uuid(dev) else False
+
+
+def is_mapped_luks_device(dev):
+    """
+    Determine if dev is a mapped LUKS device
+    :param: dev: A full path to a block device to be checked
+    :returns: boolean: indicates whether a device is mapped
+    """
+    _, dirs, _ = next(os.walk(
+        '/sys/class/block/{}/holders/'
+        .format(os.path.basename(os.path.realpath(dev))))
+    )
+    is_held = len(dirs) > 0
+    return is_held and is_luks_device(dev)
+
+
 def is_block_device(path):
     '''
     Confirm device at path is a valid block device node.

charmhelpers/core/host.py

@@ -47,6 +47,7 @@ if __platform__ == "ubuntu":
         cmp_pkgrevno,
         CompareHostReleases,
         get_distrib_codename,
+        arch
     )  # flake8: noqa -- ignore F401 for this import
 elif __platform__ == "centos":
     from charmhelpers.core.host_factory.centos import (  # NOQA:F401

charmhelpers/core/host_factory/ubuntu.py

@@ -1,5 +1,6 @@
 import subprocess
 
+from charmhelpers.core.hookenv import cached
 from charmhelpers.core.strutils import BasicStringComparator
 
 
@@ -97,3 +98,16 @@ def cmp_pkgrevno(package, revno, pkgcache=None):
         pkgcache = apt_cache()
     pkg = pkgcache[package]
     return apt_pkg.version_compare(pkg.current_ver.ver_str, revno)
+
+
+@cached
+def arch():
+    """Return the package architecture as a string.
+
+    :returns: the architecture
+    :rtype: str
+    :raises: subprocess.CalledProcessError if dpkg command fails
+    """
+    return subprocess.check_output(
+        ['dpkg', '--print-architecture']
+    ).rstrip().decode('UTF-8')

charmhelpers/core/sysctl.py

@@ -28,7 +28,7 @@ from charmhelpers.core.hookenv import (
 __author__ = 'Jorge Niedbalski R. <jorge.niedbalski@canonical.com>'
 
 
-def create(sysctl_dict, sysctl_file):
+def create(sysctl_dict, sysctl_file, ignore=False):
     """Creates a sysctl.conf file from a YAML associative array
 
     :param sysctl_dict: a dict or YAML-formatted string of sysctl
@@ -36,6 +36,8 @@ def create(sysctl_dict, sysctl_file):
     :type sysctl_dict: str
     :param sysctl_file: path to the sysctl file to be saved
     :type sysctl_file: str or unicode
+    :param ignore: If True, ignore "unknown variable" errors.
+    :type ignore: bool
     :returns: None
     """
     if type(sysctl_dict) is not dict:
@@ -52,7 +54,12 @@ def create(sysctl_dict, sysctl_file):
         for key, value in sysctl_dict_parsed.items():
             fd.write("{}={}\n".format(key, value))
 
-    log("Updating sysctl_file: %s values: %s" % (sysctl_file, sysctl_dict_parsed),
+    log("Updating sysctl_file: {} values: {}".format(sysctl_file,
+                                                     sysctl_dict_parsed),
         level=DEBUG)
 
-    check_call(["sysctl", "-p", sysctl_file])
+    call = ["sysctl", "-p", sysctl_file]
+    if ignore:
+        call.append("-e")
+
+    check_call(call)