do not put comments in /etc/timezone

comments in /etc/timezone are not expected, and can cause problems
if another tool tries to read it.

ChangeLog

@@ -14,6 +14,7 @@
  - change trunk debian packaging to use pybuild and drop cdbs.
    [Dimitri John Ledkov]
  - SeLinuxGuard: remove invalid check that looked for stat.st_mode in os.lstat.
+ - do not write comments in /etc/timezone (LP: #1341710)
 0.7.5:
  - open 0.7.5
  - Add a debug log message around import failures

cloudinit/distros/__init__.py

@@ -856,3 +856,12 @@ def fetch(name):
     mod = importer.import_module(locs[0])
     cls = getattr(mod, 'Distro')
     return cls
+
+
+def set_etc_timezone(tz, tz_file=None, tz_conf="/etc/timezone",
+                     tz_local="/etc/localtime"):
+    util.write_file(tz_conf, str(tz).rstrip() + "\n")
+    # This ensures that the correct tz will be used for the system
+    if tz_local and tz_file:
+        util.copy(tz_file, self.tz_local_fn)
+    return

cloudinit/distros/arch.py

@@ -32,8 +32,6 @@ LOG = logging.getLogger(__name__)
 class Distro(distros.Distro):
     locale_conf_fn = "/etc/locale.gen"
     network_conf_dir = "/etc/netctl"
-    tz_conf_fn = "/etc/timezone"
-    tz_local_fn = "/etc/localtime"
     resolve_conf_fn = "/etc/resolv.conf"
     init_cmd = ['systemctl']  # init scripts
 
@@ -161,16 +159,7 @@ class Distro(distros.Distro):
         return hostname
 
     def set_timezone(self, tz):
-        tz_file = self._find_tz_file(tz)
-        # Note: "" provides trailing newline during join
-        tz_lines = [
-            util.make_header(),
-            str(tz),
-            "",
-        ]
-        util.write_file(self.tz_conf_fn, "\n".join(tz_lines))
-        # This ensures that the correct tz will be used for the system
-        util.copy(tz_file, self.tz_local_fn)
+        set_etc_timezone(tz=tz, tz_file=self._find_tz_file(tz))
 
     def package_command(self, command, args=None, pkgs=None):
         if pkgs is None:

cloudinit/distros/debian.py

@@ -46,8 +46,6 @@ class Distro(distros.Distro):
     hostname_conf_fn = "/etc/hostname"
     locale_conf_fn = "/etc/default/locale"
     network_conf_fn = "/etc/network/interfaces"
-    tz_conf_fn = "/etc/timezone"
-    tz_local_fn = "/etc/localtime"
 
     def __init__(self, name, cfg, paths):
         distros.Distro.__init__(self, name, cfg, paths)
@@ -133,16 +131,7 @@ class Distro(distros.Distro):
         return "127.0.1.1"
 
     def set_timezone(self, tz):
-        tz_file = self._find_tz_file(tz)
-        # Note: "" provides trailing newline during join
-        tz_lines = [
-            util.make_header(),
-            str(tz),
-            "",
-        ]
-        util.write_file(self.tz_conf_fn, "\n".join(tz_lines))
-        # This ensures that the correct tz will be used for the system
-        util.copy(tz_file, self.tz_local_fn)
+        set_etc_timezone(tz=tz, tz_file=self._find_tz_file(tz))
 
     def package_command(self, command, args=None, pkgs=None):
         if pkgs is None:

cloudinit/distros/gentoo.py

@@ -31,8 +31,6 @@ LOG = logging.getLogger(__name__)
 class Distro(distros.Distro):
     locale_conf_fn = "/etc/locale.gen"
     network_conf_fn = "/etc/conf.d/net"
-    tz_conf_fn = "/etc/timezone"
-    tz_local_fn = "/etc/localtime"
     init_cmd = ['']  # init scripts
 
     def __init__(self, name, cfg, paths):
@@ -140,16 +138,7 @@ class Distro(distros.Distro):
         return hostname
 
     def set_timezone(self, tz):
-        tz_file = self._find_tz_file(tz)
-        # Note: "" provides trailing newline during join
-        tz_lines = [
-            util.make_header(),
-            str(tz),
-            "",
-        ]
-        util.write_file(self.tz_conf_fn, "\n".join(tz_lines))
-        # This ensures that the correct tz will be used for the system
-        util.copy(tz_file, self.tz_local_fn)
+        set_etc_timezone(tz=tz, tz_file=self._find_tz_file(tz))
 
     def package_command(self, command, args=None, pkgs=None):
         if pkgs is None: