support custom hash policy

files/interfaces.j2

@@ -51,7 +51,7 @@ bond-miimon 100
 bond-downdelay 200
 bond-updelay 200
 bond-lacp-rate 1
-bond-xmit-hash-policy layer2+3
+bond-xmit-hash-policy {{ bond.hash_policy | default('layer2+3') }}
 {% endif %}
 
 {% endfor %}

files/netplan.yaml.j2

@@ -34,7 +34,7 @@ network:
 {% if bond.mode == "802.3ad" %}
         lacp-rate: fast
         min-links: 1
-        transmit-hash-policy: layer2+3
+        transmit-hash-policy: {{ bond.hash_policy | default('layer2+3') }}
         mii-monitor-interval: 100
 {% endif %}
       dhcp4: false