addons: dhcp: add vrf awareness

Ticket: CM-10292, CM-10282
Reviewed By: dsa, nikhil, julien
Testing Done: Tested dhcp config on an vrf slave

- Add support for policy module_globals variable
  "vrf-exec-cmd-prefix". It is read into per module
  self.vrf_exec_cmd_prefix variable

- If self.vrf_exec_cmd_prefix is present and interface is a
  vrf slave, use ifupdown2 will call such command in vrf
  context using:
    "%s %s %s" %(<vrf-exec-cmd-prefix>, <vrfname>, <cmd>)

- This also fixes calling of dhcp refresh when a dhcp slave is
  removed from a vrf

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>

addons/dhcp.py

@@ -31,9 +31,14 @@ class dhcp(moduleBase):
                              ifaceobj.name)
             return
         try:
+            dhclient_cmd_prefix = None
             dhcp_wait = policymanager.policymanager_api.get_attr_default(
                 module_name=self.__class__.__name__, attr='dhcp-wait')
             wait = not str(dhcp_wait).lower() == "no"
+            vrf = ifaceobj.get_attr_value_first('vrf')
+            if vrf and self.vrf_exec_cmd_prefix:
+                dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix, vrf)
+
             if ifaceobj.addr_family == 'inet':
                 # First release any existing dhclient processes
                 try:
@@ -41,7 +46,8 @@ class dhcp(moduleBase):
                         self.dhclientcmd.stop(ifaceobj.name)
                 except:
                     pass
-                self.dhclientcmd.start(ifaceobj.name, wait=wait)
+                self.dhclientcmd.start(ifaceobj.name, wait=wait,
+                                       cmd_prefix=dhclient_cmd_prefix)
             elif ifaceobj.addr_family == 'inet6':
                 accept_ra = ifaceobj.get_attr_value_first('accept_ra')
                 if accept_ra:
@@ -57,12 +63,17 @@ class dhcp(moduleBase):
                         self.dhclientcmd.stop6(ifaceobj.name)
                     except:
                         pass
-                self.dhclientcmd.start6(ifaceobj.name, wait=wait)
+                self.dhclientcmd.start6(ifaceobj.name, wait=wait,
+                                        cmd_prefix=dhclient_cmd_prefix)
         except Exception, e:
             self.log_error(str(e))
 
     def _down(self, ifaceobj):
-        self.dhclientcmd.release(ifaceobj.name)
+        dhclient_cmd_prefix = None
+        vrf = ifaceobj.get_attr_value_first('vrf')
+        if vrf and self.vrf_exec_cmd_prefix:
+            dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix, vrf)
+        self.dhclientcmd.release(ifaceobj.name, dhclient_cmd_prefix)
         self.ipcmd.link_down(ifaceobj.name)
 
     def _query_check(self, ifaceobj, ifaceobjcurr):

addons/vrf.py

@@ -313,9 +313,13 @@ class vrf(moduleBase):
         self.ipcmd.link_set(ifacename, 'master', vrfname)
         return
 
-    def _down_dhcp_slave(self, ifaceobj):
+    def _down_dhcp_slave(self, ifaceobj, vrfname):
         try:
-            self.dhclientcmd.release(ifaceobj.name)
+            dhclient_cmd_prefix = None
+            if vrfname and self.vrf_exec_cmd_prefix:
+                dhclient_cmd_prefix = '%s %s' %(self.vrf_exec_cmd_prefix,
+                                                vrfname)
+            self.dhclientcmd.release(ifaceobj.name, dhclient_cmd_prefix)
         except:
             # ignore any dhclient release errors
             pass
@@ -327,7 +331,7 @@ class vrf(moduleBase):
             self.vrf_mgmt_devname == vrfname):
             self._kill_ssh_connections(ifaceobj.name)
         if self._is_dhcp_slave(ifaceobj):
-            self._down_dhcp_slave(ifaceobj)
+            self._down_dhcp_slave(ifaceobj, vrfname)
 
     def _up_vrf_slave(self, ifacename, vrfname, ifaceobj=None,
                       ifaceobj_getfunc=None, vrf_exists=False):
@@ -681,6 +685,7 @@ class vrf(moduleBase):
                     # check if we were a slave before
                     master = self.ipcmd.link_get_master(ifaceobj.name)
                     if master:
+                        self._iproute2_vrf_map_initialize()
                         if self._is_vrf_dev(master):
                             self._down_vrf_slave(ifaceobj.name, ifaceobj,
                                                  master)
@@ -701,7 +706,7 @@ class vrf(moduleBase):
             vrf_table = self._get_iproute2_vrf_table(ifaceobj.name)
 
         try:
-            self.exec_command('/usr/cumulus/bin/cl-vrf service disable %s' %ifaceobj.name)
+            self.exec_command('/usr/bin/vrf service disable %s' %ifaceobj.name)
         except Exception, e:
             self.logger.info('%s: %s' %(ifaceobj.name, str(e)))
             pass

ifupdownaddons/dhclient.py

@@ -29,7 +29,18 @@ class dhclient(utilsBase):
     def is_running6(self, ifacename):
         return self._pid_exists('/run/dhclient6.%s.pid' %ifacename)
 
-    def stop(self, ifacename):
+    def _run_dhclient_cmd(self, cmd, cmd_prefix=None):
+        if not cmd_prefix:
+            cmd_aslist = []
+        else:
+            cmd_aslist = cmd_prefix.split()
+        if cmd_aslist:
+            cmd_aslist.extend(cmd)
+        else:
+            cmd_aslist = cmd
+        self.subprocess_check_call(cmd_aslist)
+
+    def stop(self, ifacename, cmd_prefix=None):
         if os.path.exists('/sbin/dhclient3'):
             cmd = ['/sbin/dhclient3', '-x', '-pf',
                    '/run/dhclient.%s.pid' %ifacename, '-lf',
@@ -40,23 +51,24 @@ class dhclient(utilsBase):
                    '/run/dhclient.%s.pid' %ifacename,
                    '-lf', '/var/lib/dhcp/dhclient.%s.leases' %ifacename,
                    '%s' %ifacename]
-        self.subprocess_check_call(cmd)
+        self._run_dhclient_cmd(cmd, cmd_prefix)
 
-    def start(self, ifacename, wait=True):
+    def start(self, ifacename, wait=True, cmd_prefix=None):
         if os.path.exists('/sbin/dhclient3'):
             cmd = ['/sbin/dhclient3', '-pf',
                    '/run/dhclient.%s.pid' %ifacename,
                    '-lf', '/var/lib/dhcp3/dhclient.%s.leases' %ifacename,
                    '%s' %ifacename]
         else:
-            cmd = ['/sbin/dhclient', '-pf', '/run/dhclient.%s.pid' %ifacename,
-                   '-lf', '/var/lib/dhcp/dhclient.%s.leases' %ifacename,
+            cmd = ['/sbin/dhclient', '-pf',
+                   '/run/dhclient.%s.pid' %ifacename, '-lf',
+                   '/var/lib/dhcp/dhclient.%s.leases' %ifacename,
                    '%s' %ifacename]
         if not wait:
             cmd.append('-nw')
-        self.subprocess_check_call(cmd)
+        self._run_dhclient_cmd(cmd, cmd_prefix)
 
-    def release(self, ifacename):
+    def release(self, ifacename, cmd_prefix=None):
         if os.path.exists('/sbin/dhclient3'):
             cmd = ['/sbin/dhclient3', '-r', '-pf',
                    '/run/dhclient.%s.pid' %ifacename, '-lf',
@@ -67,25 +79,27 @@ class dhclient(utilsBase):
                    '/run/dhclient.%s.pid' %ifacename,
                    '-lf', '/var/lib/dhcp/dhclient.%s.leases' %ifacename,
                    '%s' %ifacename]
-        self.subprocess_check_call(cmd)
+        self._run_dhclient_cmd(cmd, cmd_prefix)
 
-    def start6(self, ifacename, wait=True):
-        cmd = ['dhclient', '-6', '-pf',
+    def start6(self, ifacename, wait=True, cmd_prefix=None):
+        cmd = ['/sbin/dhclient', '-6', '-pf',
                 '/run/dhclient6.%s.pid' %ifacename, '-lf',
                 '/var/lib/dhcp/dhclient.%s.leases ' %ifacename,
                 '%s' %ifacename]
         if not wait:
             cmd.append('-nw')
-        self.subprocess_check_call(cmd)
+        self._run_dhclient_cmd(cmd, cmd_prefix)
 
-    def stop6(self, ifacename):
-        self.subprocess_check_call(['dhclient', '-6', '-x', '-pf',
-                '/run/dhclient.%s.pid' %ifacename, '-lf',
-                '/var/lib/dhcp/dhclient.%s.leases ' %ifacename,
-                '%s' %ifacename])
+    def stop6(self, ifacename, cmd_prefix=None):
+        cmd = ['/sbin/dhclient', '-6', '-x', '-pf',
+               '/run/dhclient.%s.pid' %ifacename, '-lf',
+               '/var/lib/dhcp/dhclient.%s.leases ' %ifacename,
+               '%s' %ifacename]
+        self._run_dhclient_cmd(cmd, cmd_prefix)
 
-    def release6(self, ifacename):
-        self.subprocess_check_call(['dhclient', '-6', '-r', '-pf',
-                '/run/dhclient6.%s.pid' %ifacename, '-lf',
-                '/var/lib/dhcp/dhclient6.%s.leases' %ifacename,
-                '%s' %ifacename])
+    def release6(self, ifacename, cmd_prefix=None):
+        cmd = ['/sbin/dhclient', '-6', '-r', '-pf',
+               '/run/dhclient6.%s.pid' %ifacename, '-lf',
+               '/var/lib/dhcp/dhclient6.%s.leases' %ifacename,
+               '%s' %ifacename]
+        self._run_dhclient_cmd(cmd, cmd_prefix)

ifupdownaddons/modulebase.py

@@ -15,6 +15,7 @@ import shlex
 
 from ifupdown.utils import utils
 from ifupdown.iface import *
+import ifupdown.policymanager as policymanager
 #from ifupdownaddons.iproute2 import *
 #from ifupdownaddons.dhclient import *
 #from ifupdownaddons.bridgeutils import *
@@ -38,6 +39,11 @@ class moduleBase(object):
         self.CACHE = kargs.get('cache', False)
         self.CACHE_FLAGS = kargs.get('cacheflags', 0x0)
 
+        # vrfs are a global concept and a vrf context can be applicable
+        # to all global vrf commands. Get the default vrf-exec-cmd-prefix
+        # here so that all modules can use it
+        self.vrf_exec_cmd_prefix = policymanager.policymanager_api.get_module_globals('vrf', attr='vrf-exec-cmd-prefix')
+
     def log_warn(self, str, ifaceobj=None):
         """ log a warning if err str is not one of which we should ignore """
         if not self.ignore_error(str):