xenserver: Add --root-prefix feature to interface-reconfigure.

This makes it easier to do unit tests (some of which will be added in an
upcoming commit) by allowing fake configuration files and scripts to be
added in a directory other than the real root.

Signed-off-by: Ben Pfaff <blp@nicira.com>

xenserver/opt_xensource_libexec_InterfaceReconfigure.py

@@ -16,6 +16,15 @@ import os
 from xml.dom.minidom import getDOMImplementation
 from xml.dom.minidom import parse as parseXML
 
+the_root_prefix = ""
+def root_prefix():
+    """Returns a string to prefix to all file name references, which
+    is useful for testing."""
+    return the_root_prefix
+def set_root_prefix(prefix):
+    global the_root_prefix
+    the_root_prefix = prefix
+
 #
 # Logging.
 #
@@ -38,7 +47,7 @@ class Error(Exception):
 
 def run_command(command):
     log("Running command: " + ' '.join(command))
-    rc = os.spawnl(os.P_WAIT, command[0], *command)
+    rc = os.spawnl(os.P_WAIT, root_prefix() + command[0], *command)
     if rc != 0:
         log("Command failed %d: " % rc + ' '.join(command))
         return False
@@ -323,7 +332,7 @@ def db_init_from_xenapi(session):
     
 class DatabaseCache(object):
     def __read_xensource_inventory(self):
-        filename = "/etc/xensource-inventory"
+        filename = root_prefix() + "/etc/xensource-inventory"
         f = open(filename, "r")
         lines = [x.strip("\n") for x in f.readlines()]
         f.close()
@@ -440,7 +449,7 @@ class DatabaseCache(object):
         else:
             log("Loading xapi database cache from %s" % cache_file)
 
-            xml = parseXML(cache_file)
+            xml = parseXML(root_prefix() + cache_file)
 
             self.__pifs = {}
             self.__bonds = {}
@@ -625,7 +634,7 @@ def pif_ipdev_name(pif):
 #
 
 def netdev_exists(netdev):
-    return os.path.exists("/sys/class/net/" + netdev)
+    return os.path.exists(root_prefix() + "/sys/class/net/" + netdev)
 
 def pif_netdev_name(pif):
     """Get the netdev name for a PIF."""
@@ -806,7 +815,7 @@ def DatapathFactory(pif):
     # XXX Need a datapath object for bridgeless PIFs
 
     try:
-        network_conf = open("/etc/xensource/network.conf", 'r')
+        network_conf = open(root_prefix() + "/etc/xensource/network.conf", 'r')
         network_backend = network_conf.readline().strip()
         network_conf.close()                
     except Exception, e:

xenserver/opt_xensource_libexec_InterfaceReconfigureBridge.py

@@ -15,7 +15,7 @@ from InterfaceReconfigure import *
 import sys
 import time
 
-sysfs_bonding_masters = "/sys/class/net/bonding_masters"
+sysfs_bonding_masters = root_prefix() + "/sys/class/net/bonding_masters"
 
 def open_pif_ifcfg(pif):
     pifrec = db().get_pif_record(pif)
@@ -23,7 +23,7 @@ def open_pif_ifcfg(pif):
     interface = pif_netdev_name(pif)
     log("Configuring %s (%s)" % (interface, pifrec['MAC']))
 
-    f = ConfigurationFile("/etc/sysconfig/network-scripts/ifcfg-%s" % interface)
+    f = ConfigurationFile("%s/etc/sysconfig/network-scripts/ifcfg-%s" % (root_prefix(), interface))
 
     f.write("# DO NOT EDIT: This file (%s) was autogenerated by %s\n" % \
             (os.path.basename(f.path()), os.path.basename(sys.argv[0])))
@@ -69,7 +69,7 @@ def load_bonding_driver():
         log("Failed to load bonding driver: %s" % e)
 
 def bonding_driver_loaded():
-    lines = open("/proc/modules").read().split("\n")
+    lines = open(root_prefix() + "/proc/modules").read().split("\n")
     modules = [line.split(" ")[0] for line in lines]
     return "bonding" in modules
 
@@ -226,7 +226,7 @@ def bring_down_interface(pif, destroy=False):
 def interface_is_up(pif):
     try:
         interface = pif_netdev_name(pif)
-        state = open("/sys/class/net/%s/operstate" % interface).read().strip()
+        state = open("%s/sys/class/net/%s/operstate" % (root_prefix(), interface)).read().strip()
         return state == "up"
     except:
         return False # interface prolly doesn't exist
@@ -294,7 +294,7 @@ def pif_get_bond_slaves_sorted(pif):
     # which they were attached.  The first slave attached must be the last detached since
     # the bond is using its MAC address.
     try:
-        attached_slaves = open("/sys/class/net/%s/bonding/slaves" % pifrec['device']).readline().split()
+        attached_slaves = open("%s/sys/class/net/%s/bonding/slaves" % (root_prefix(), pifrec['device'])).readline().split()
         for slave in attached_slaves:
             pifs = [p for p in db().get_pifs_by_device(slave) if not pif_is_vlan(p)]
             slave_pif = pifs[0]

xenserver/opt_xensource_libexec_interface-reconfigure

@@ -33,6 +33,7 @@
     --pif               A PIF reference within the session.
     --pif-uuid          The UUID of a PIF.
     --force             An interface name.
+    --root-prefix=DIR   Use DIR as alternate root directory (for testing).
 """
 
 # Notes:
@@ -88,7 +89,7 @@ def check_allowed(pif):
 
     pifrec = db().get_pif_record(pif)
     try:
-        f = open("/proc/ardence")
+        f = open(root_prefix() + "/proc/ardence")
         macline = filter(lambda x: x.startswith("HWaddr:"), f.readlines())
         f.close()
         if len(macline) == 1:
@@ -121,20 +122,20 @@ def netdev_remap_name(pif, already_renamed=[]):
 
     def get_netdev_mac(device):
         try:
-            return read1("/sys/class/net/%s/address" % device)
+            return read1("%s/sys/class/net/%s/address" % (root_prefix(), device))
         except:
             # Probably no such device.
             return None
 
     def get_netdev_tx_queue_len(device):
         try:
-            return int(read1("/sys/class/net/%s/tx_queue_len" % device))
+            return int(read1("%s/sys/class/net/%s/tx_queue_len" % (root_prefix(), device)))
         except:
             # Probably no such device.
             return None
 
     def get_netdev_by_mac(mac):
-        for device in os.listdir("/sys/class/net"):
+        for device in os.listdir(root_prefix() + "/sys/class/net"):
             dev_mac = get_netdev_mac(device)
             if (dev_mac and mac.lower() == dev_mac.lower() and
                 get_netdev_tx_queue_len(device)):
@@ -185,7 +186,7 @@ def ifdown(netdev):
     if not netdev_exists(netdev):
         log("ifdown: device %s does not exist, ignoring" % netdev)
         return
-    if not os.path.exists("/etc/sysconfig/network-scripts/ifcfg-%s" % netdev):
+    if not os.path.exists("%s/etc/sysconfig/network-scripts/ifcfg-%s" % (root_prefix(), netdev)):
         log("ifdown: device %s exists but ifcfg-%s does not" % (netdev,netdev))
         run_command(["/sbin/ifconfig", netdev, 'down'])
         return
@@ -193,7 +194,7 @@ def ifdown(netdev):
 
 def ifup(netdev):
     """Bring up a network interface"""
-    if not os.path.exists("/etc/sysconfig/network-scripts/ifcfg-%s" % netdev):
+    if not os.path.exists(root_prefix() + "/etc/sysconfig/network-scripts/ifcfg-%s" % netdev):
         raise Error("ifup: device %s exists but ifcfg-%s does not" % (netdev,netdev))
     run_command(["/sbin/ifup", netdev])
 
@@ -238,7 +239,7 @@ def ipdev_configure_static_routes(interface, oc, f):
         # The key is not present, i.e. there are no static routes
         lines = []
 
-    child = ConfigurationFile("/etc/sysconfig/network-scripts/route-%s" % interface)
+    child = ConfigurationFile("%s/etc/sysconfig/network-scripts/route-%s" % (root_prefix(), interface))
     child.write("# DO NOT EDIT: This file (%s) was autogenerated by %s\n" % \
             (os.path.basename(child.path()), os.path.basename(sys.argv[0])))
 
@@ -258,7 +259,7 @@ def ipdev_open_ifcfg(pif):
 
     log("Writing network configuration for %s" % ipdev)
 
-    f = ConfigurationFile("/etc/sysconfig/network-scripts/ifcfg-%s" % ipdev)
+    f = ConfigurationFile("%s/etc/sysconfig/network-scripts/ifcfg-%s" % (root_prefix(), ipdev))
 
     f.write("# DO NOT EDIT: This file (%s) was autogenerated by %s\n" % \
             (os.path.basename(f.path()), os.path.basename(sys.argv[0])))
@@ -382,7 +383,7 @@ def ipdev_configure_network(pif, dp):
     is_gatewaydev = defaultroute_pif == pif
 
     if is_dnsdev or is_gatewaydev:
-        fnetwork = ConfigurationFile("/etc/sysconfig/network")
+        fnetwork = ConfigurationFile(root_prefix() + "/etc/sysconfig/network")
         for line in fnetwork.readlines():
             if is_dnsdev and line.lstrip().startswith('DNSDEV='):
                 fnetwork.write('DNSDEV=%s\n' % ipdev)
@@ -441,7 +442,7 @@ def action_up(pif, force):
         dp.post()
 
         # Update /etc/issue (which contains the IP address of the management interface)
-        os.system("/sbin/update-issue")
+        os.system(root_prefix() + "/sbin/update-issue")
 
         f.commit()
     except Error, e:
@@ -502,7 +503,7 @@ def action_force_rewrite(bridge, config):
 
     log("Configuring %s using %s configuration" % (bridge, mode))
 
-    f = ConfigurationFile(dbcache_file)
+    f = ConfigurationFile(root_prefix() + dbcache_file)
 
     pif_uuid = getUUID()
     network_uuid = getUUID()
@@ -580,6 +581,7 @@ def main(argv=None):
                         "force-interface=",
                         "management",
                         "mac=", "device=", "mode=", "ip=", "netmask=", "gateway=",
+                        "root-prefix=",
                         "help" ]
             arglist, args = getopt.gnu_getopt(argv[1:], shortops, longops)
         except getopt.GetoptError, msg:
@@ -600,6 +602,8 @@ def main(argv=None):
                 force_management = True
             elif o in ["--mac", "--device", "--mode", "--ip", "--netmask", "--gateway"]:
                 force_rewrite_config[o[2:]] = a
+            elif o == "--root-prefix":
+                set_root_prefix(a)
             elif o == "-h" or o == "--help":
                 print __doc__ % {'command-name': os.path.basename(argv[0])}
                 return 0