Allow configuring network connection via matching path

Users can easily configure or update network connection via matching
physical device path of the interface, which add certain flexibilty of
user experience.

Update connection profile via matching `path` setting:

```yaml
  - name: eth0
    type: ethernet
    autoconnect: yes
    # For PCI devices, the path has the form "pci-$domain:$bus:$device.$function"
    # It will only update the interface with the path "pci-0000:00:03.0"
    match:
      path:
        - pci-0000:00:03.0
```

Signed-off-by: Wen Liang <liangwen12year@gmail.com>

module_utils/network_lsr/argument_validator.py

@@ -400,25 +400,34 @@ class ArgValidatorDict(ArgValidator):
 
 
 class ArgValidatorList(ArgValidator):
-    def __init__(self, name, nested, default_value=None):
+    def __init__(
+        self,
+        name,
+        nested,
+        default_value=None,
+        remove_none_or_empty=False,
+    ):
         ArgValidator.__init__(self, name, required=False, default_value=default_value)
         self.nested = nested
+        self.remove_none_or_empty = remove_none_or_empty
 
     def _validate_impl(self, value, name):
 
-        if isinstance(value, Util.STRING_TYPE):
-            # we expect a list. However, for convenience allow to
-            # specify a string, separated by space. Escaping is
-            # not supported. If you need that, define a proper list.
-            value = [s for s in value.split(" ") if s]
-
         if value is None:
             # Users might want to use jinja2 templates to set properties. As such,
             # it's convenient to accept None as an alias for an empty list
             # e.g. setting like `"match": {"path": None}` will be allowed by the role
-            return []
+            value = []
+        elif isinstance(value, Util.STRING_TYPE):
+            # we expect a list. However, for convenience allow to
+            # specify a string, separated by space. Escaping is
+            # not supported. If you need that, define a proper list.
+            value = [s for s in value.split(" ") if s]
+
         result = []
         for (idx, v) in enumerate(value):
+            if (v is None or v == "") and self.remove_none_or_empty:
+                continue
             try:
                 vv = self.nested._validate(v, name + "[" + str(idx) + "]")
             except ValidationError as e:
@@ -1270,6 +1279,45 @@ class ArgValidator_DictWireless(ArgValidatorDict):
         return result
 
 
+class ArgValidatorListMatchPath(ArgValidatorList):
+    def __init__(self, name, nested, default_value, remove_none_or_empty):
+        ArgValidatorList.__init__(
+            self,
+            name,
+            nested,
+            default_value,
+            remove_none_or_empty,
+        )
+
+    def _validate_impl(self, value, name):
+        result = ArgValidatorList._validate_impl(self, value, name)
+        if result == ["|"] or result == ["&"]:
+            raise ValidationError(
+                name,
+                "value '%s' is not a valid 'match.path' setting, after "
+                "normalization, '%s' will only match the devices that have no PCI "
+                "path" % (value, result),
+            )
+        return result
+
+
+class ArgValidator_DictMatch(ArgValidatorDict):
+    def __init__(self):
+        ArgValidatorDict.__init__(
+            self,
+            name="match",
+            nested=[
+                ArgValidatorListMatchPath(
+                    "path",
+                    nested=ArgValidatorStr("path[?]", allow_empty=True),
+                    default_value=None,
+                    remove_none_or_empty=True,
+                ),
+            ],
+            default_value={},
+        )
+
+
 class ArgValidator_DictConnection(ArgValidatorDict):
 
     VALID_PERSISTENT_STATES = ["absent", "present"]
@@ -1340,6 +1388,7 @@ class ArgValidator_DictConnection(ArgValidatorDict):
                 ArgValidator_DictMacvlan(),
                 ArgValidator_Dict802_1X(),
                 ArgValidator_DictWireless(),
+                ArgValidator_DictMatch(),
                 # deprecated options:
                 ArgValidatorStr(
                     "infiniband_transport_mode",
@@ -1563,6 +1612,15 @@ class ArgValidator_DictConnection(ArgValidatorDict):
                         "but is '%s'" % result["mac"],
                     )
 
+            if result.get("match"):
+                if "path" in result["match"]:
+                    if result["type"] not in ["ethernet", "infiniband"]:
+                        raise ValidationError(
+                            name + ".match.path",
+                            "'match.path' settings are only supported for type "
+                            "'ethernet' or 'infiniband'",
+                        )
+
             if result["type"] == "infiniband":
                 if "infiniband" not in result:
                     result["infiniband"] = self.nested[
@@ -1627,7 +1685,9 @@ class ArgValidator_DictConnection(ArgValidatorDict):
                         "invalid 'interface_name' '%s'" % (result["interface_name"]),
                     )
             else:
-                if not result.get("mac"):
+                if not result.get("mac") and (
+                    not result.get("match") or not result["match"].get("path")
+                ):
                     if not Util.ifname_valid(result["name"]):
                         raise ValidationError(
                             name + ".interface_name",
@@ -1921,3 +1981,18 @@ class ArgValidator_ListConnections(ArgValidatorList):
                     "Setting DNS options 'inet6', 'ip6-bytestring', 'ip6-dotint', "
                     "'no-ip6-dotint' is not allowed when IPv6 is disabled.",
                 )
+
+        if connection["match"]:
+            if connection["match"]["path"]:
+                if mode == self.VALIDATE_ONE_MODE_INITSCRIPTS:
+                    raise ValidationError.from_connection(
+                        idx,
+                        "match.path is not supported by initscripts.",
+                    )
+                else:
+                    if not hasattr(Util.NM(), "SETTING_MATCH_PATH"):
+                        raise ValidationError.from_connection(
+                            idx,
+                            "match.path is not supported by the running version of "
+                            "NetworkManger.",
+                        )