bonding: T2877: support configuration of minimum number of active links

Specifies the minimum number of links that must be active before asserting
carrier. It is similar to the Cisco EtherChannel min-links feature. This allows
setting the minimum number of member ports that must be up (link-up state)
before marking the bond device as up (carrier on). This is useful for situations
where higher level services such as clustering want to ensure a minimum number
of low bandwidth links are active before switchover.

This option only affects 802.3ad mode.

The default value is 0. This will cause carrier to be asserted (for 802.3ad
mode) whenever there is an active aggregator, regardless of the number of
available links in that aggregator. Note that, because an aggregator cannot be
active without at least one available link, setting this option to 0 or to 1
has the exact same effect.

1 files changed, 31 insertions, 0 deletions

diff --git a/python/vyos/ifconfig/bond.py b/python/vyos/ifconfig/bond.py
index 64407401b..67dcd2b69 100644
--- a/python/vyos/ifconfig/bond.py
+++ b/python/vyos/ifconfig/bond.py
@@ -52,6 +52,10 @@ class BondIf(Interface):
             'validate': lambda v: assert_list(v, ['layer2', 'layer2+3', 'layer3+4', 'encap2+3', 'encap3+4']),
             'location': '/sys/class/net/{ifname}/bonding/xmit_hash_policy',
         },
+        'bond_min_links': {
+            'validate': assert_positive,
+            'location': '/sys/class/net/{ifname}/bonding/min_links',
+        },
         'bond_miimon': {
             'validate': assert_positive,
             'location': '/sys/class/net/{ifname}/bonding/miimon'
@@ -130,6 +134,29 @@ class BondIf(Interface):
         """
         self.set_interface('bond_hash_policy', mode)
 
+    def set_min_links(self, number):
+        """
+        Specifies the minimum number of links that must be active before
+	    asserting carrier. It is similar to the Cisco EtherChannel min-links
+	    feature. This allows setting the minimum number of member ports that
+	    must be up (link-up state) before marking the bond device as up
+	    (carrier on). This is useful for situations where higher level services
+	    such as clustering want to ensure a minimum number of low bandwidth
+	    links are active before switchover. This option only affect 802.3ad
+	    mode.
+
+	    The default value is 0. This will cause carrier to be asserted (for
+	    802.3ad mode) whenever there is an active aggregator, regardless of the
+	    number of available links in that aggregator. Note that, because an
+	    aggregator cannot be active without at least one available link,
+	    setting this option to 0 or to 1 has the exact same effect.
+
+        Example:
+        >>> from vyos.ifconfig import BondIf
+        >>> BondIf('bond0').set_min_links('0')
+        """
+        self.set_interface('bond_min_links', number)
+
     def set_arp_interval(self, interval):
         """
         Specifies the ARP link monitoring frequency in milliseconds.
@@ -347,6 +374,10 @@ class BondIf(Interface):
         value = config.get('hash_policy')
         if value: self.set_hash_policy(value)
 
+        # Minimum number of member interfaces
+        value = config.get('min_links')
+        if value: self.set_min_links(value)
+
         # Some interface options can only be changed if the interface is
         # administratively down
         if self.get_admin_state() == 'down':