Reboot of Amphora does not work with altname in ip link

[Daniel Failing]

In newer kernel/ip versions there are aliases for the interfaces configured.
Because of this, the interfaces for the member and listener are not moved to the correct network namespace.

Line in question:
https://opendev.org/openstack/octavia/src/branch/master/octavia/amphorae/backends/agent/api_server/templates/amphora-netns.systemd.j2#L29

Output from /sbin/ip link:
```
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
    link/ether fa:aa:bb:cc:11:21 brd ff:ff:ff:ff:ff:ff
    altname enp0s3
3: ens7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
    link/ether fa:aa:bb:cc:11:22 brd ff:ff:ff:ff:ff:ff
    altname enp0s7
```
With this `awk '{getline n; print $0,n}'` will contatinate the wrong lines.
It can be fixed by adding `grep -e mtu -e link`, but maybe a better approach for this line is needed.

[Gregory Thiemonge (gthiemonge)]

I confirm this issue, after rebooting a centos 9 stream amphora, the vip and member interfaces are in the "main" network namespace:

bash-5.1# cat /var/lib/octavia/plugged_interfaces
fa:16:3e:34:0c:9e eth1
fa:16:3e:33:a4:5d eth2
bash-5.1# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1442 qdisc fq_codel state UP group default qlen 1000
    link/ether fa:16:3e:e6:32:a8 brd ff:ff:ff:ff:ff:ff
    altname enp0s3
    inet 192.168.0.172/24 brd 192.168.0.255 scope global noprefixroute ens3
       valid_lft forever preferred_lft forever
    inet6 fe80::f816:3eff:fee6:32a8/64 scope link
       valid_lft forever preferred_lft forever
3: ens7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether fa:16:3e:34:0c:9e brd ff:ff:ff:ff:ff:ff
    altname enp0s7
4: ens8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1442 qdisc fq_codel state UP group default qlen 1000
    link/ether fa:16:3e:33:a4:5d brd ff:ff:ff:ff:ff:ff
    altname enp0s8

the amphora-interface application cannot configure those interfaces:

Jul 17 11:43:32 amphora-5a7dab8e-fbeb-4c15-be6b-b0e698dffe8b.novalocal ip[475]: 2023-07-17 11:43:32.815 475 INFO octavia.common.config [-] Logging enabled!
Jul 17 11:43:32 amphora-5a7dab8e-fbeb-4c15-be6b-b0e698dffe8b.novalocal ip[475]: 2023-07-17 11:43:32.817 475 INFO octavia.common.config [-] /usr/local/bin/amphora-interface version 12.1.0.dev72
Jul 17 11:43:32 amphora-5a7dab8e-fbeb-4c15-be6b-b0e698dffe8b.novalocal ip[475]: 2023-07-17 11:43:32.822 475 INFO octavia.amphorae.backends.utils.interface [-] Setting interface eth2 up
Jul 17 11:43:32 amphora-5a7dab8e-fbeb-4c15-be6b-b0e698dffe8b.novalocal ip[475]: 2023-07-17 11:43:32.824 475 INFO octavia.amphorae.backends.utils.interface [-] Setting interface eth1 up
Jul 17 11:43:32 amphora-5a7dab8e-fbeb-4c15-be6b-b0e698dffe8b.novalocal ip[475]: 2023-07-17 11:43:32.825 475 INFO octavia.amphorae.backends.utils.interface [-] Setting interface lo up
Jul 17 11:43:32 amphora-5a7dab8e-fbeb-4c15-be6b-b0e698dffe8b.novalocal ip[475]: Error: Could not configure interface: Error on action 'up' for interface eth2: list index out of range., Error on action 'up' for interface eth1: list index out of range.

[Thong Tran (thongth98)]

I encountered an issue related to network interface name alias support in the new kernel, specifically while testing on Ubuntu 22.04.

To resolve this problem, I made adjustments to a script responsible for assigning interfaces to namespaces. These adjustments involved removing the alternate name using the 'grep -v "altname"' command.

Link source:
https://opendev.org/openstack/octavia/src/branch/master/octavia/amphorae/backends/agent/api_server/templates/amphora-netns.systemd.j2#L29

Fix:
ExecStart=-/bin/sh -c '/sbin/ip link | grep -v "altname" | awk \'{getline n; print $0,n}\' | awk \'{sub(":","",$2)} { for(i=1;i<=NF;i++) if ($i == "link/ether") {print $(i+1) " " $2} }\' | sort -k 1 | join -j 1 - /var/lib/octavia/plugged_interfaces.sorted | awk \'{system("ip link set "$2" netns amphora-haproxy name "$3"")}\''

[Gregory Thiemonge (gthiemonge)]

Thanks for the fixes, I think this line is unreadable and I would be in favor of:
- fixing this issue with a grep (-v altname or -e mtu -e link) on master and stable branches
- creating a readable (python?) script that would replace some of the messy things that are in this systemd file (probably not backportable)