improve the updating of /etc/hosts with correct fqdn when possible

Thanks to Adam Gandalman and Marc Cluet for this fix.

LP: #812539

1 files changed, 40 insertions, 37 deletions

diff --git a/cloudinit/CloudConfig/cc_update_etc_hosts.py b/cloudinit/CloudConfig/cc_update_etc_hosts.py
index 10ee5435..b3098f29 100644
--- a/cloudinit/CloudConfig/cc_update_etc_hosts.py
+++ b/cloudinit/CloudConfig/cc_update_etc_hosts.py
@@ -17,57 +17,60 @@
 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 import cloudinit.util as util
 from cloudinit.CloudConfig import per_always
-import platform
 import StringIO
 
 frequency = per_always
 
 def handle(name,cfg,cloud,log,args):
-    if not util.get_cfg_option_bool(cfg,"manage_etc_hosts",False):
+    hostname = util.get_cfg_option_str(cfg,"hostname",cloud.get_hostname())
+    fqdn = util.get_cfg_option_str(cfg,"fqdn",cloud.get_hostname(fqdn=True))
+
+    if util.get_cfg_option_bool(cfg,"manage_etc_hosts", True):
+        # manage_etc_hosts not true, update the 127.0.1.1 entry via update_etc_hosts
         log.debug("manage_etc_hosts is not set, checking sanity of /etc/hosts")
-        with open('/etc/hosts', 'r') as etchosts:
-            current_hostname = platform.node()
-            hosts_line = "# Added by cloud-init\n127.0.1.1\t%s.localdomain %s\n" % (current_hostname, current_hostname)
-            need_write = False
-            need_change = True
-            new_etchosts = StringIO.StringIO()
-            for line in etchosts:
-                split_line = [s.strip() for s in line.split()]
-                # skip over malformed /etc/hosts entries
-                if len(split_line) < 2:
-                    continue
-                ip, hostnames = split_line[0], split_line[1:]
-                if ip == "127.0.1.1":
-                    for hostname in hostnames:
-                        if hostname == current_hostname:
-                            need_change = False
-                    if need_change == True:
-                        line = hosts_line
-                        need_change = False
-                        need_write = True
-                new_etchosts.write(line)
-            etchosts.close()
-            if need_change == True:
-                new_etchosts.write(hosts_line)
-                need_write = True
-            if need_write == True:
-                new_etcfile = open ('/etc/hosts','wb')
-                new_etcfile.write(new_etchosts.getvalue())
-                new_etcfile.close()
-            new_etchosts.close()
+        update_etc_hosts(hostname, fqdn, log)
         return
 
+    # manage_etc_hosts is set, render from template file
     try:
-        hostname = util.get_cfg_option_str(cfg,"hostname",cloud.get_hostname())
-        if not hostname:
-            hostname = cloud.get_hostname()
-
         if not hostname:
             log.info("manage_etc_hosts was set, but no hostname found")
             return
 
-        util.render_to_file('hosts', '/etc/hosts', { 'hostname' : hostname })
+        util.render_to_file('hosts', '/etc/hosts', \
+            { 'hostname' : hostname, 'fqdn' : fqdn })
 
     except Exception as e:
         log.warn("failed to update /etc/hosts")
         raise
+
+def update_etc_hosts(hostname, fqdn, log):
+     with open('/etc/hosts', 'r') as etchosts:
+         hosts_line = "# Added by cloud-init\n127.0.1.1\t%s %s\n" % (fqdn, hostname)
+         need_write = False
+         need_change = True
+         new_etchosts = StringIO.StringIO()
+         for line in etchosts:
+             split_line = [s.strip() for s in line.split()]
+             # skip over malformed /etc/hosts entries
+             if len(split_line) < 2:
+                 continue
+             ip, hosts = split_line[0], split_line[1:]
+             if ip == "127.0.1.1":
+                 if sorted([hostname, fqdn]) == sorted(hosts):
+                     need_change = False
+                 if need_change == True:
+                     line = hosts_line
+                     need_change = False
+                     need_write = True
+             new_etchosts.write(line)
+         etchosts.close()
+         if need_change == True:
+             new_etchosts.write(hosts_line)
+             need_write = True
+         if need_write == True:
+             new_etcfile = open ('/etc/hosts','wb')
+             new_etcfile.write(new_etchosts.getvalue())
+             new_etcfile.close()
+         new_etchosts.close()
+     return