Always set hostname

This prevents cases when hostname on system is set inconsistently
(transient and static hostname differs) and may cause IPA errors.

This commit ensures that all hostnames are set properly.

https://fedorahosted.org/freeipa/ticket/5794

Reviewed-By: David Kupka <dkupka@redhat.com>

ipaplatform/base/paths.py

@@ -25,7 +25,7 @@ This base platform module exports default filesystem paths.
 class BasePathNamespace(object):
     BASH = "/bin/bash"
     BIN_FALSE = "/bin/false"
-    BIN_HOSTNAME = "/bin/hostname"
+    BIN_HOSTNAMECTL = "/bin/hostnamectl"
     LS = "/bin/ls"
     SH = "/bin/sh"
     SYSTEMCTL = "/bin/systemctl"

ipaplatform/base/tasks.py

@@ -48,7 +48,7 @@ class BaseTaskNamespace(object):
     def backup_and_replace_hostname(self, fstore, statestore, hostname):
         """
         Backs up the current hostname in the statestore (so that it can be
-        restored by the restore_network_configuration platform task).
+        restored by the restore_hostname platform task).
 
         Makes sure that new hostname (passed via hostname argument) is set
         as a new pemanent hostname for this host.
@@ -106,7 +106,7 @@ class BaseTaskNamespace(object):
 
         return
 
-    def restore_network_configuration(self, fstore, statestore):
+    def restore_hostname(self, fstore, statestore):
         """
         Restores the original hostname as backed up in the
         backup_and_replace_hostname platform task.
@@ -237,6 +237,14 @@ class BaseTaskNamespace(object):
         """
         return parse_version(version)
 
+    def set_hostname(self, hostname):
+        """
+        Set hostname for the system
+
+        No return value expected, raise CalledProcessError when error occurred
+        """
+        return
+
     def configure_httpd_service_ipa_conf(self):
         """Configure httpd service to work with IPA"""
         raise NotImplementedError()

ipaplatform/redhat/tasks.py

@@ -26,10 +26,10 @@ system tasks.
 from __future__ import print_function
 
 import os
-import stat
 import socket
-import sys
 import base64
+import traceback
+
 from cffi import FFI
 from ctypes.util import find_library
 from functools import total_ordering
@@ -330,38 +330,31 @@ class RedHatTaskNamespace(BaseTaskNamespace):
     def backup_and_replace_hostname(self, fstore, statestore, hostname):
         old_hostname = socket.gethostname()
         try:
-            ipautil.run([paths.BIN_HOSTNAME, hostname])
+            self.set_hostname(hostname)
         except ipautil.CalledProcessError as e:
             print(("Failed to set this machine hostname to "
                                  "%s (%s)." % (hostname, str(e))), file=sys.stderr)
 
         filepath = paths.ETC_HOSTNAME
         if os.path.exists(filepath):
-            # read old hostname
-            with open(filepath, 'r') as f:
-                for line in f.readlines():
-                    line = line.strip()
-                    if not line or line.startswith('#'):
-                        # skip comment or empty line
-                        continue
-                    old_hostname = line
-                    break
             fstore.backup_file(filepath)
 
-        with open(filepath, 'w') as f:
-            f.write("%s\n" % hostname)
-        os.chmod(filepath,
-                 stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP | stat.S_IROTH)
-        os.chown(filepath, 0, 0)
-        self.restore_context(filepath)
-
         # store old hostname
         statestore.backup_state('network', 'hostname', old_hostname)
 
-    def restore_network_configuration(self, fstore, statestore):
+    def restore_hostname(self, fstore, statestore):
         old_filepath = paths.SYSCONFIG_NETWORK
         old_hostname = statestore.get_state('network', 'hostname')
-        hostname_was_configured = False
+
+        if old_hostname is not None:
+            try:
+                self.set_hostname(old_hostname)
+            except ipautil.CalledProcessError as e:
+                root_logger.debug(traceback.format_exc())
+                root_logger.error(
+                    "Failed to restore this machine hostname to %s (%s).",
+                    old_hostname, e
+                )
 
         if fstore.has_file(old_filepath):
             # This is Fedora >=18 instance that was upgraded from previous
@@ -371,20 +364,11 @@ class RedHatTaskNamespace(BaseTaskNamespace):
             fstore.restore_file(old_filepath, old_filepath_restore)
             print("Deprecated configuration file '%s' was restored to '%s'" \
                     % (old_filepath, old_filepath_restore))
-            hostname_was_configured = True
 
         filepath = paths.ETC_HOSTNAME
         if fstore.has_file(filepath):
             fstore.restore_file(filepath)
-            hostname_was_configured = True
 
-        if not hostname_was_configured and old_hostname:
-            # hostname was not configured before but was set by IPA. Delete
-            # /etc/hostname to restore previous configuration
-            try:
-                os.remove(filepath)
-            except OSError:
-                pass
 
     def set_selinux_booleans(self, required_settings, backup_func=None):
         def get_setsebool_args(changes):
@@ -490,4 +474,7 @@ class RedHatTaskNamespace(BaseTaskNamespace):
                 paths.SYSTEMD_SYSTEM_HTTPD_IPA_CONF, e
             )
 
+    def set_hostname(self, hostname):
+        ipautil.run([paths.BIN_HOSTNAMECTL, 'set-hostname', hostname])
+
 tasks = RedHatTaskNamespace()