merge from master at 17.2-30-gf7deaf15

1 files changed, 18 insertions, 13 deletions

diff --git a/cloudinit/distros/__init__.py b/cloudinit/distros/__init__.py
index d5becd12..55260eae 100755
--- a/cloudinit/distros/__init__.py
+++ b/cloudinit/distros/__init__.py
@@ -45,6 +45,10 @@ OSFAMILIES = {
 
 LOG = logging.getLogger(__name__)
 
+# This is a best guess regex, based on current EC2 AZs on 2017-12-11.
+# It could break when Amazon adds new regions and new AZs.
+_EC2_AZ_RE = re.compile('^[a-z][a-z]-(?:[a-z]+-)+[0-9][a-z]$')
+
 
 @six.add_metaclass(abc.ABCMeta)
 class Distro(object):
@@ -102,11 +106,8 @@ class Distro(object):
         self._apply_hostname(writeable_hostname)
 
     def uses_systemd(self):
-        try:
-            res = os.lstat('/run/systemd/system')
-            return stat.S_ISDIR(res.st_mode)
-        except Exception:
-            return False
+        """Wrapper to report whether this distro uses systemd or sysvinit."""
+        return uses_systemd()
 
     @abc.abstractmethod
     def package_command(self, cmd, args=None, pkgs=None):
@@ -686,18 +687,13 @@ def _get_package_mirror_info(mirror_info, data_source=None,
     if not mirror_info:
         mirror_info = {}
 
-    # ec2 availability zones are named cc-direction-[0-9][a-d] (us-east-1b)
-    # the region is us-east-1. so region = az[0:-1]
-    directions_re = '|'.join([
-        'central', 'east', 'north', 'northeast', 'northwest',
-        'south', 'southeast', 'southwest', 'west'])
-    ec2_az_re = ("^[a-z][a-z]-(%s)-[1-9][0-9]*[a-z]$" % directions_re)
-
     subst = {}
     if data_source and data_source.availability_zone:
         subst['availability_zone'] = data_source.availability_zone
 
-        if re.match(ec2_az_re, data_source.availability_zone):
+        # ec2 availability zones are named cc-direction-[0-9][a-d] (us-east-1b)
+        # the region is us-east-1. so region = az[0:-1]
+        if _EC2_AZ_RE.match(data_source.availability_zone):
             subst['ec2_region'] = "%s" % data_source.availability_zone[0:-1]
 
     if data_source and data_source.region:
@@ -761,4 +757,13 @@ def set_etc_timezone(tz, tz_file=None, tz_conf="/etc/timezone",
             util.copy(tz_file, tz_local)
     return
 
+
+def uses_systemd():
+    try:
+        res = os.lstat('/run/systemd/system')
+        return stat.S_ISDIR(res.st_mode)
+    except Exception:
+        return False
+
+
 # vi: ts=4 expandtab