Add support for systemd environments and use it to support Fedora 16

https://fedorahosted.org/freeipa/ticket/1192

4 files changed, 339 insertions, 12 deletions

diff --git a/ipapython/platform/base.py b/ipapython/platform/base.py
index f9d409972..99189a101 100644
--- a/ipapython/platform/base.py
+++ b/ipapython/platform/base.py
@@ -22,7 +22,7 @@ from ipalib.plugable import MagicDict
 # set them as in Red Hat distributions. Actual implementation should make them available
 # through knownservices.<name> and take care of remapping internally, if needed
 wellknownservices = ['certmonger', 'dirsrv', 'httpd', 'ipa', 'krb5kdc', 'messagebus',
-                     'nslcd', 'nscd', 'ntpd', 'portmap', 'rpcbind']
+                     'nslcd', 'nscd', 'ntpd', 'portmap', 'rpcbind', 'kadmin']
 
 class AuthConfig(object):
     """
@@ -120,25 +120,25 @@ class PlatformService(object):
     def restart(self, instance_name="", capture_output=True):
         return
 
-    def is_running(self):
+    def is_running(self, instance_name=""):
         return False
 
     def is_installed(self):
         return False
 
-    def is_enabled(self):
+    def is_enabled(self, instance_name=""):
         return False
 
-    def enable(self):
+    def enable(self, instance_name=""):
         return
 
-    def disable(self):
+    def disable(self, instance_name=""):
         return
 
-    def install(self):
+    def install(self, instance_name=""):
         return
 
-    def remove(self):
+    def remove(self, instance_name=""):
         return
 
 class KnownServices(MagicDict):
diff --git a/ipapython/platform/fedora16.py b/ipapython/platform/fedora16.py
new file mode 100644
index 000000000..0e476928e
--- /dev/null
+++ b/ipapython/platform/fedora16.py
@@ -0,0 +1,123 @@
+# Author: Alexander Bokovoy <abokovoy@redhat.com>
+#
+# Copyright (C) 2011   Red Hat
+# see file 'COPYING' for use and warranty information
+#
+# This program 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.
+#
+# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+from ipapython import ipautil
+from ipapython.platform import base, redhat, systemd
+import os
+
+# All what we allow exporting directly from this module
+# Everything else is made available through these symbols when they directly imported into ipapython.services:
+# authconfig -- class reference for platform-specific implementation of authconfig(8)
+# service    -- class reference for platform-specific implementation of a PlatformService class
+# knownservices -- factory instance to access named services IPA cares about, names are ipapython.services.wellknownservices
+# backup_and_replace_hostname -- platform-specific way to set hostname and make it persistent over reboots
+# restore_context -- platform-sepcific way to restore security context, if applicable
+__all__ = ['authconfig', 'service', 'knownservices', 'backup_and_replace_hostname', 'restore_context']
+
+# For beginning just remap names to add .service
+# As more services will migrate to systemd, unit names will deviate and
+# mapping will be kept in this dictionary
+system_units = dict(map(lambda x: (x, "%s.service" % (x)), base.wellknownservices))
+
+# Rewrite dirsrv and pki-cad services as they support instances via separate service generator
+# To make this working, one needs to have both foo@.service and foo.target -- the latter is used
+# when request should be coming for all instances (like stop). systemd, unfortunately, does not allow
+# to request action for all service instances at once if only foo@.service unit is available.
+# To add more, if any of those services need to be started/stopped automagically, one needs to manually
+# create symlinks in /etc/systemd/system/foo.target.wants/ (look into systemd.py's enable() code).
+system_units['dirsrv'] = 'dirsrv@.service'
+# Our directory server instance for PKI is dirsrv@PKI-IPA.service
+system_units['pkids'] = 'dirsrv@PKI-IPA.service'
+# Our PKI instance is pki-cad@pki-ca.service
+system_units['pki-cad'] = 'pki-cad@pki-ca.service'
+
+class Fedora16Service(systemd.SystemdService):
+    def __init__(self, service_name):
+        if service_name in system_units:
+            service_name = system_units[service_name]
+        else:
+            if len(service_name.split('.')) == 1:
+                # if service_name does not have a dot, it is not foo.service and not a foo.target
+                # Thus, not correct service name for systemd, default to foo.service style then
+                service_name = "%s.service" % (service_name)
+        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.
+# 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):
+            # 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
+            replacevars = {'LimitNOFILE':'8192'}
+            ipautil.config_replace_variables(srv_etc, replacevars=replacevars)
+            redhat.restore_context(srv_etc)
+            ipautil.run(["/bin/systemctl", "--system", "daemon-reload"],raiseonerr=False)
+
+    def restart(self, instance_name="", capture_output=True):
+        if len(instance_name) > 0:
+            elements = self.service_name.split("@")
+            srv_etc = os.path.join(self.SYSTEMD_ETC_PATH, self.service_name)
+            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))
+            if not os.path.exists(srv_etc):
+                self.enable(instance_name)
+            elif not os.path.samefile(srv_etc, srv_lnk):
+                os.unlink(srv_lnk)
+                os.symlink(srv_etc, srv_lnk)
+        super(Fedora16DirectoryService, self).restart(instance_name, capture_output=capture_output)
+
+# Enforce restart of IPA services when we do enable it
+# This gets around the fact that after ipa-server-install systemd thinks ipa.service is not yet started
+# but all services were actually started already.
+class Fedora16IPAService(Fedora16Service):
+    def enable(self, instance_name=""):
+        super(Fedora16IPAService, self).enable(instance_name)
+        self.restart(instance_name)
+
+# Redirect directory server service through special sub-class due to its special handling of instances
+def f16_service(name):
+    if name == 'dirsrv':
+        return Fedora16DirectoryService(name)
+    if name == 'ipa':
+        return Fedora16IPAService(name)
+    return Fedora16Service(name)
+
+class Fedora16Services(base.KnownServices):
+    def __init__(self):
+        services = dict()
+        for s in base.wellknownservices:
+            services[s] = f16_service(s)
+        # Call base class constructor. This will lock services to read-only
+        super(Fedora16Services, self).__init__(services)
+
+authconfig = redhat.authconfig
+service = f16_service
+knownservices = Fedora16Services()
+restore_context = redhat.restore_context
+backup_and_replace_hostname = redhat.backup_and_replace_hostname
diff --git a/ipapython/platform/redhat.py b/ipapython/platform/redhat.py
index 5ac310609..d99a91747 100644
--- a/ipapython/platform/redhat.py
+++ b/ipapython/platform/redhat.py
@@ -66,20 +66,20 @@ class RedHatService(base.PlatformService):
                 installed = False
         return installed
 
-    def is_enabled(self):
+    def is_enabled(self, instance_name=""):
         (stdout, stderr, returncode) = ipautil.run(["/sbin/chkconfig", self.service_name],raiseonerr=False)
         return (returncode == 0)
 
-    def enable(self):
+    def enable(self, instance_name=""):
         ipautil.run(["/sbin/chkconfig", self.service_name, "on"])
 
-    def disable(self):
+    def disable(self, instance_name=""):
         ipautil.run(["/sbin/chkconfig", self.service_name, "off"])
 
-    def install(self):
+    def install(self, instance_name=""):
         ipautil.run(["/sbin/chkconfig", "--add", self.service_name])
 
-    def remove(self):
+    def remove(self, instance_name=""):
         ipautil.run(["/sbin/chkconfig", "--del", self.service_name])
 
 class RedHatAuthConfig(base.AuthConfig):
diff --git a/ipapython/platform/systemd.py b/ipapython/platform/systemd.py
new file mode 100644
index 000000000..3f1fe730e
--- /dev/null
+++ b/ipapython/platform/systemd.py
@@ -0,0 +1,204 @@
+# Author: Alexander Bokovoy <abokovoy@redhat.com>
+#
+# Copyright (C) 2011   Red Hat
+# see file 'COPYING' for use and warranty information
+#
+# This program 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.
+#
+# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+from ipapython import ipautil
+from ipapython.platform import base
+import sys, os, shutil
+
+class SystemdService(base.PlatformService):
+    SYSTEMD_ETC_PATH = "/etc/systemd/system/"
+    SYSTEMD_LIB_PATH = "/lib/systemd/system/"
+    SYSTEMD_SRV_TARGET = "%s.target.wants"
+
+    def __init__(self, service_name):
+        super(SystemdService, self).__init__(service_name)
+        self.lib_path = os.path.join(self.SYSTEMD_LIB_PATH, self.service_name)
+        self.lib_path_exists = None
+
+    def service_instance(self, instance_name):
+        if self.lib_path_exists is None:
+            self.lib_path_exists = os.path.exists(self.lib_path)
+
+        elements = self.service_name.split("@")
+
+        # Short-cut: if there is already exact service name, return it
+        if self.lib_path_exists and len(instance_name) == 0:
+            if len(elements) == 1:
+                # service name is like pki-cad.target or krb5kdc.service
+                return self.service_name
+            if len(elements) > 1 and elements[1][0] != '.':
+                # Service name is like pki-cad@pki-ca.service and that file exists
+                return self.service_name
+
+        if len(elements) > 1:
+            # We have dynamic service
+            if len(instance_name) > 0:
+                # Instanciate dynamic service
+                return "%s@%s.service" % (elements[0], instance_name)
+            else:
+                # No instance name, try with target
+                tgt_name = "%s.target" % (elements[0])
+                srv_lib = os.path.join(self.SYSTEMD_LIB_PATH, tgt_name)
+                if os.path.exists(srv_lib):
+                    return tgt_name
+
+        return self.service_name
+
+    def parse_variables(self, text, separator=None):
+        """
+        Parses 'systemctl show' output and returns a dict[variable]=value
+        Arguments: text -- 'systemctl show' output as string
+                   separator -- optional (defaults to None), what separates the key/value pairs in the text
+        """
+        def splitter(x, separator=None):
+            if len(x) > 1:
+                y = x.split(separator)
+                return (y[0], y[-1])
+            return (None,None)
+        return dict(map(lambda x: splitter(x, separator=separator), text.split("\n")))
+
+    def stop(self, instance_name="", capture_output=True):
+        ipautil.run(["/bin/systemctl", "stop", self.service_instance(instance_name)], capture_output=capture_output)
+
+    def start(self, instance_name="", capture_output=True):
+        ipautil.run(["/bin/systemctl", "start", self.service_instance(instance_name)], capture_output=capture_output)
+
+    def restart(self, instance_name="", capture_output=True):
+        # Restart command is broken before systemd-36-3.fc16
+        # If you have older systemd version, restart of dependent services will hang systemd indefinetly
+        ipautil.run(["/bin/systemctl", "restart", self.service_instance(instance_name)], capture_output=capture_output)
+
+    def is_running(self, instance_name=""):
+        ret = True
+        try:
+            (sout, serr, rcode) = ipautil.run(["/bin/systemctl", "is-active", self.service_instance(instance_name)],capture_output=True)
+            if rcode != 0:
+                ret = False
+        except ipautil.CalledProcessError:
+                ret = False
+        return ret
+
+    def is_installed(self):
+        installed = True
+        try:
+            (sout,serr,rcode) = ipautil.run(["/bin/systemctl", "list-unit-files", "--full"])
+            if rcode != 0:
+                installed = False
+            else:
+                svar = self.parse_variables(sout)
+                if not self.service_instance("") in svar:
+                    # systemd doesn't show the service
+                    installed = False
+        except ipautil.CalledProcessError, e:
+                installed = False
+        return installed
+
+    def is_enabled(self, instance_name=""):
+        enabled = True
+        try:
+            (sout,serr,rcode) = ipautil.run(["/bin/systemctl", "is-enabled", self.service_instance(instance_name)])
+            if rcode != 0:
+                enabled = False
+        except ipautil.CalledProcessError, e:
+                enabled = False
+        return enabled
+
+    def enable(self, instance_name=""):
+        if self.lib_path_exists is None:
+            self.lib_path_exists = os.path.exists(self.lib_path)
+        elements = self.service_name.split("@")
+        l = len(elements)
+
+        if self.lib_path_exists and (l > 1 and elements[1][0] != '.'):
+            # There is explicit service unit supporting this instance, follow normal systemd enabler
+            self.__enable(instance_name)
+            return
+
+        if self.lib_path_exists and (l == 1):
+            # There is explicit service unit which does not support the instances, ignore instance
+            self.__enable()
+            return
+
+        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)
+            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):
+                    # Remove old link
+                    os.unlink(srv_lnk)
+                if not os.path.exists(srv_lnk):
+                    # 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)
+                    else:
+                        # Link exists and it is broken, make new one
+                        os.unlink(srv_lnk)
+                        os.symlink(srv_etc, srv_lnk)
+                ipautil.run(["/bin/systemctl", "--system", "daemon-reload"])
+            except:
+                pass
+        else:
+            self.__enable(instance_name)
+
+    def disable(self, instance_name=""):
+        elements = self.service_name.split("@")
+        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
+            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 ipautil.dir_exists(srv_tgt):
+                    if os.path.islink(srv_lnk):
+                        os.unlink(srv_lnk)
+                ipautil.run(["/bin/systemctl", "--system", "daemon-reload"])
+            except:
+                pass
+        else:
+            self.__disable(instance_name)
+
+    def __enable(self, instance_name=""):
+        try:
+            ipautil.run(["/bin/systemctl", "enable", self.service_instance(instance_name)])
+        except ipautil.CalledProcessError, e:
+            pass
+
+    def __disable(self, instance_name=""):
+        try:
+            ipautil.run(["/bin/systemctl", "disable", self.service_instance(instance_name)])
+        except ipautil.CalledProcessError, e:
+            pass
+
+    def install(self):
+        self.enable()
+
+    def remove(self):
+        self.disable()