Handle upgrade issues with systemd in Fedora 16 and above

Since 389-ds-base-1.2.10-0.8.a7 Directory Server's systemd settings are
configured via /etc/sysconfig/dirsrv.systemd. It means logic change in
systemd/fedora16 platform of FreeIPA.

Additionally, existing installs need to be handled during upgrade.

Fixes:
    https://fedorahosted.org/freeipa/ticket/2117
    https://fedorahosted.org/freeipa/ticket/2300

ipapython/platform/fedora16.py

@@ -59,24 +59,24 @@ class Fedora16Service(systemd.SystemdService):
         super(Fedora16Service, self).__init__(service_name)
 
 # Special handling of directory server service
-# LimitNOFILE needs to be increased or any value set in the directory for this value will fail
-# Read /lib/systemd/system/dirsrv@.service for details.
-# We do modification of LimitNOFILE on service.enable() but we also need to explicitly enable instances
-# to install proper symlinks as dirsrv.target.wants/ dependencies. Unfortunately, ipa-server-install
-# does not do explicit dirsrv.enable() because the service startup is handled by ipactl.
+#
+# We need to explicitly enable instances to install proper symlinks as dirsrv.target.wants/
+# dependencies. Standard systemd service class does it on #enable() method call. Unfortunately,
+# ipa-server-install does not do explicit dirsrv.enable() because the service startup is handled by ipactl.
+#
 # If we wouldn't do this, our instances will not be started as systemd would not have any clue
 # about instances (PKI-IPA and the domain we serve) at all. Thus, hook into dirsrv.restart().
 class Fedora16DirectoryService(Fedora16Service):
     def enable(self, instance_name=""):
         super(Fedora16DirectoryService, self).enable(instance_name)
-        srv_etc = os.path.join(self.SYSTEMD_ETC_PATH, self.service_name)
-        if os.path.exists(srv_etc):
+        dirsrv_systemd = "/etc/sysconfig/dirsrv.systemd"
+        if os.path.exists(dirsrv_systemd):
             # We need to enable LimitNOFILE=8192 in the dirsrv@.service
-            # We rely on the fact that [Service] section is the last one
-            # and if variable is not there, it will be added as the last line
+            # Since 389-ds-base-1.2.10-0.8.a7 the configuration of the service parameters is performed
+            # via /etc/sysconfig/dirsrv.systemd file which is imported by systemd into dirsrv@.service unit
             replacevars = {'LimitNOFILE':'8192'}
-            ipautil.config_replace_variables(srv_etc, replacevars=replacevars)
-            redhat.restore_context(srv_etc)
+            ipautil.inifile_replace_variables(dirsrv_systemd, 'service', replacevars=replacevars)
+            redhat.restore_context(dirsrv_systemd)
             ipautil.run(["/bin/systemctl", "--system", "daemon-reload"],raiseonerr=False)
 
     def restart(self, instance_name="", capture_output=True):

ipapython/platform/systemd.py

@@ -137,16 +137,12 @@ class SystemdService(base.PlatformService):
 
         if len(instance_name) > 0 and l > 1:
             # New instance, we need to do following:
-            # 1. Copy <service>@.service to /etc/systemd/system/ if it is not there
-            # 2. Make /etc/systemd/system/<service>.target.wants/ if it is not there
-            # 3. Link /etc/systemd/system/<service>.target.wants/<service>@<instance_name>.service to
-            #    /etc/systemd/system/<service>@.service
-            srv_etc = os.path.join(self.SYSTEMD_ETC_PATH, self.service_name)
+            # 1. Make /etc/systemd/system/<service>.target.wants/ if it is not there
+            # 2. Link /etc/systemd/system/<service>.target.wants/<service>@<instance_name>.service to
+            #    /lib/systemd/system/<service>@.service
             srv_tgt = os.path.join(self.SYSTEMD_ETC_PATH, self.SYSTEMD_SRV_TARGET % (elements[0]))
             srv_lnk = os.path.join(srv_tgt, self.service_instance(instance_name))
             try:
-                if not ipautil.file_exists(srv_etc):
-                    shutil.copy(self.lib_path, srv_etc)
                 if not ipautil.dir_exists(srv_tgt):
                     os.mkdir(srv_tgt)
                 if os.path.exists(srv_lnk):
@@ -156,11 +152,11 @@ class SystemdService(base.PlatformService):
                     # object does not exist _or_ is a broken link
                     if not os.path.islink(srv_lnk):
                         # if it truly does not exist, make a link
-                        os.symlink(srv_etc, srv_lnk)
+                        os.symlink(self.lib_path, srv_lnk)
                     else:
                         # Link exists and it is broken, make new one
                         os.unlink(srv_lnk)
-                        os.symlink(srv_etc, srv_lnk)
+                        os.symlink(self.lib_path, srv_lnk)
                 ipautil.run(["/bin/systemctl", "--system", "daemon-reload"])
             except:
                 pass
@@ -172,7 +168,7 @@ class SystemdService(base.PlatformService):
         if instance_name != "" and len(elements) > 1:
             # Remove instance, we need to do following:
             #  Remove link from /etc/systemd/system/<service>.target.wants/<service>@<instance_name>.service
-            #  to /etc/systemd/system/<service>@.service
+            #  to /lib/systemd/system/<service>@.service
             srv_tgt = os.path.join(self.SYSTEMD_ETC_PATH, self.SYSTEMD_SRV_TARGET % (elements[0]))
             srv_lnk = os.path.join(srv_tgt, self.service_instance(instance_name))
             try: