xr-compose - Allow specifying the Linux interface name for management interfaces

[jillesca]

When xr-compose processes a topology with a macvlan management network, it generates XR_MGMT_INTERFACES using an internal network counter (e.g. linux:xr-n120).

Docker names macvlan interfaces inside the container eth0, not xr-n<N>. The generated output is therefore incorrect for macvlan-based management networks and XRd boots up with the management interface mapped to a non-existant container interface.

Current output (8-node SR topology)

XR_MGMT_INTERFACES: linux:xr-n120,xr_name=Mg0/RP0/CPU0/0,chksum,snoop_v4,snoop_v4_default_route

Required value

XR_MGMT_INTERFACES: linux:eth0,xr_name=Mg0/RP0/CPU0/0,chksum,snoop_v4,snoop_v4_default_route

Request

Add a way to specify the Linux interface name for management interfaces, either:

1. In the .xr.yml — e.g. a linux_name field on the mgmt interface entry:

xr_interfaces:
  - Mg0/RP0/CPU0/0:
      snoop_v4: True
      snoop_v4_default_route: True
      linux_name: eth0

2. As a CLI flag — e.g. --mgmt-linux-interface eth0, applied globally to all XR_MGMT_INTERFACES entries.

Workaround in use today

I currently post-process the generated file with a script that targets only XR_MGMT_INTERFACES lines and replaces linux:xr-n[0-9]+ with linux:eth0 - https://github.com/CiscoDevNet/XRd-Sandbox/blob/main/scripts/lib/fix-mgmt-interface.sh