d57c97fdb6
This PR will introduce a new field to v1alpha1 configs that allows users
to set `dummy: true` when specifying interfaces. If present, we will
create a dummy interface with the CIDR information given. This is useful
for users that don't want to use loopback for things like ECMP (or want
more than one dummy interface).
The created dummy interface looked like this with `ip a`:
```
3: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN qlen 1000
link/ether 66:4a:e3:5f:38:10 brd ff:ff:ff:ff:ff:ff
inet 10.254.0.5/32 brd 10.254.0.5 scope global dummy0
valid_lft forever preferred_lft forever
```
Will close #2186.
Signed-off-by: Spencer Smith <robertspencersmith@gmail.com>