Started the good, the bad and the ugly - code cleanup.

cdist/util/ipaddr.py

@@ -0,0 +1,57 @@
+# -*- coding: utf-8 -*-
+#
+# 2016 Darko Poljak (darko.poljak at gmail.com)
+#
+# This file is part of cdist.
+#
+# cdist is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# cdist 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with cdist. If not, see <http://www.gnu.org/licenses/>.
+#
+#
+
+import socket
+import logging
+
+
+def resolve_target_addresses(host):
+    log = logging.getLogger(host)
+    try:
+        # getaddrinfo returns a list of 5-tuples:
+        # (family, type, proto, canonname, sockaddr)
+        # where sockaddr is:
+        # (address, port) for AF_INET,
+        # (address, port, flow_info, scopeid) for AF_INET6
+        ip_addr = socket.getaddrinfo(
+                host, None, type=socket.SOCK_STREAM)[0][4][0]
+        # gethostbyaddr returns triple
+        # (hostname, aliaslist, ipaddrlist)
+        host_name = socket.gethostbyaddr(ip_addr)[0]
+        log.debug("derived host_name for host \"{}\": {}".format(
+            host, host_name))
+    except (socket.gaierror, socket.herror) as e:
+        log.warn("Could not derive host_name for {}"
+                 ", $host_name will be empty. Error is: {}".format(host, e))
+        # in case of error provide empty value
+        host_name = ''
+
+    try:
+        host_fqdn = socket.getfqdn(host)
+        log.debug("derived host_fqdn for host \"{}\": {}".format(
+            host, host_fqdn))
+    except socket.herror as e:
+        log.warn("Could not derive host_fqdn for {}"
+                 ", $host_fqdn will be empty. Error is: {}".format(host, e))
+        # in case of error provide empty value
+        host_fqdn = ''
+
+    return (host, host_name, host_fqdn)