Add support for fixed ip interface names on linux

Use the macvtap link type for that.

For example, with this resource configuration:

[ip#0]
ipname = 10.24.0.20
netmask = 24
ipdev = foo@eth0
alias = false

A start executes:

  /sbin/ip link add link eth0 name foo type macvtap
  /sbin/ip link set dev foo up
  /sbin/ip addr add 10.24.0.20/24 dev foo
  send gratuitous arp to announce 10.24.0.20 is at foo

opensvc/drivers/resource/ip/__init__.py

@@ -32,7 +32,7 @@
     "keyword": "ipdev",
     "at": True,
     "required": True,
-    "text": "The interface name over which OpenSVC will try to stack the service ip. Can be different from one node to the other, in which case the ``@nodename`` can be specified. If the value is expressed as '<intf>:<alias>, the stacked interface index is forced to <alias> instead of the lowest free integer."
+    "text": "The interface name over which OpenSVC will try to stack the service ip. Can be different from one node to the other, in which case the ``@nodename`` can be specified. If the value is expressed as '<intf>:<alias>, the stacked interface index is forced to <alias> instead of the lowest free integer. If the value is expressed as <name>@<intf>, a macvtap interface named <name> is created and attached to <intf>."
 }
 KW_NETMASK = {
     "keyword": "netmask",
@@ -163,13 +163,20 @@ def __init__(self,
                  provisioner=None,
                  **kwargs):
         super(Ip, self).__init__(type=type, **kwargs)
-        self.ipdev = ipdev.split(":", 1)[0]
+        self.forced_stacked_dev = None
+        self.base_ipdev = None
+        if ":" in ipdev:
+            self.ipdev = ipdev.split(":", 1)[0]
+            self.forced_stacked_dev = ipdev
+        elif "@" in ipdev:
+            self.ipdev, self.base_ipdev = ipdev.split("@", 1)
+        else:
+            self.ipdev = ipdev
         self.ipname = ipname
         self.netmask = netmask
         self.gateway = gateway
         self.lockfd = None
         self.stacked_dev = None
-        self.forced_stacked_dev = ipdev if ":" in ipdev else None
         self.addr = None
         self.expose = expose
         self.check_carrier = check_carrier
@@ -384,6 +391,12 @@ def abort_start(self):
             return True
         return False
 
+    def add_link(self):
+        pass
+
+    def del_link(self):
+        pass
+
     def start_link(self):
         """
         Start the ipdev link.
@@ -470,6 +483,7 @@ def allow_start(self):
         if self.is_up() is True:
             self.log.info("%s is already up on %s", self.addr, self.ipdev)
             raise ex.IpAlreadyUp(self.addr)
+        self.add_link()
         ifconfig = self.get_ifconfig()
         intf = ifconfig.interface(self.ipdev)
         if self.has_carrier(intf) is False and not self.svc.options.force:
@@ -726,6 +740,8 @@ def stop(self):
             self.log.error("%s refuse to go down", self.addr)
             raise ex.Error
 
+        self.del_link()
+
     def allocate(self):
         """
         Request an ip in the ipdev network from the collector.

opensvc/drivers/resource/ip/host/linux.py

@@ -4,7 +4,7 @@
 from .. import Ip
 from env import Env
 from utilities.net.converters import to_cidr, to_dotted
-from utilities.proc import which
+from utilities.proc import which, justcall
 
 DRIVER_GROUP = "ip"
 DRIVER_BASENAME = "host"
@@ -14,6 +14,38 @@ def check_ping(self, count=1, timeout=5):
         self.log.info("checking %s availability (%ss)", self.addr, timeout)
         return utilities.ping.check_ping(self.addr, timeout=timeout, count=count)
 
+    def has_macvtap_link(self):
+        cmd = [Env.syspaths.ip, "link", "ls", "dev", self.ipdev]
+        out, err, ret = justcall(cmd)
+        mark = "%s@%s" % (self.ipdev, self.base_ipdev)
+        return ret == 0 and mark in out
+
+    def del_macvtap_link(self):
+        if not self.base_ipdev:
+            return
+        if not self.has_macvtap_link():
+            return
+        cmd = [Env.syspaths.ip, "link", "del", "link", self.base_ipdev, "name", self.ipdev, "type", "macvtap"]
+        ret, out, err = self.vcall(cmd)
+        if ret:
+            raise ex.Error
+
+    def add_macvtap_link(self):
+        if not self.base_ipdev:
+            return
+        if self.has_macvtap_link():
+            return
+        cmd = [Env.syspaths.ip, "link", "add", "link", self.base_ipdev, "name", self.ipdev, "type", "macvtap"]
+        ret, out, err = self.vcall(cmd)
+        if ret:
+            raise ex.Error
+
+    def add_link(self):
+        self.add_macvtap_link()
+
+    def del_link(self):
+        self.del_macvtap_link()
+
     def start_link(self):
         if which(Env.syspaths.ip):
            cmd = [Env.syspaths.ip, 'link', 'set', 'dev', self.ipdev, 'up']
@@ -23,6 +55,9 @@ def start_link(self):
         if ret != 0:
             return ret, out, err
 
+    def stop_link(self):
+        self.del_macvtap_link()
+
     def startip_cmd(self):
         if which("ifconfig") and self.alias:
             if ':' in self.addr: