cloud-init network config 2 rename does not match with name

This bug was originally filed in Launchpad as [LP: #1788972](https://bugs.launchpad.net/cloud-init/+bug/1788972)

Launchpad details

affected_projects = []

assignee = None

assignee_name = None

date_closed = None

date_created = 2018-08-25T01:59:40.367027+00:00

date_fix_committed = None

date_fix_released = None

id = 1788972

importance = medium

is_complete = False

lp_url = https://bugs.launchpad.net/cloud-init/+bug/1788972

milestone = None

owner = csaikia

owner_name = Chaynika Saikia

private = False

status = triaged

submitter = csaikia

submitter_name = Chaynika Saikia

tags = ['bitesize', 'cloud-init']

duplicates = []

_Launchpad user **Chaynika Saikia(csaikia)** wrote on 2018-08-25T01:59:40.367027+00:00_

Looking at the source code of cloud-init, when it tries to read a network configuration file, it looks for MAC address. Looking at the source code, it gives an impression that MAC address is a requirement to rename interfaces.

However, looking at this documentation, https://cloudinit.readthedocs.io/en/latest/topics/network-config-format-v2.html , it mentions that if I want to rename a network interface, I can use either name, macaddress or driver.

This is the most misleading part because, firstly, the source code does NOT search through 'name' and uses 'device_id' instead, whereas the documentation says:
"name: <(scalar)>

Current interface name. Globs are supported, and the primary use case for matching on names, as selecting one fixed name can be more easily achieved with having no match: at all and just using the ID (see above). Note that currently only networkd supports globbing, NetworkManager does not."