Code review comment for ~darren-birkett/cloud-init:fix-infiniband-1847114

Hi Ryan,

I've tested a netplan config with the truncated mac addr (as generated in the current cloud-init code: mac = mac[36:-14] + mac[51:]) from an ib interface, and netplan doesn't seem able to match the device so doesn't configure it properly. I also tried using the final 6 bytes of the long ib mac, and then tried with the first 6 bytes. None of them match the device.

Example not working-

---
network:
    version: 2
    ethernets:
        ib0:
            addresses:
            - 192.168.207.26/24
            mtu: 9000
            match:
                macaddress: a0:00:02:20:fe:80
            set-name: ib0
---

Removing the mac matching completely from the config allows netplan to apply the config and bring the device up, at the risk of not matching the correct device at some point depending on how the device gets enumerated.

Example working-

---
network:
    version: 2
    ethernets:
        ib0:
            addresses:
            - 192.168.207.26/24
            mtu: 9000
---