Improve network endpoints order, keep the interfaces order as it whether the container has been restarted or not

[DrAuYueng]

[Signed-off-by: DrAuYueng ouyang1204@gmail.com

Currently there is no way to keep the order for network endpoints , when we run a container with --network flag which referred a pre-created network and connect container to other networks one by one, like this:

docker network create -d bridge --subnet 172.28.0.0/16 mynet1

docker network create -d bridge --subnet 172.29.0.0/16 mynet2

docker run -tid --net mynet2 --name foo busybox

docker network connect mynet1 foo

Show ip info after connect network to container foo:

docker exec -ti foo ip a

ip info:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue 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
2: tunl0@NONE: <NOARP> mtu 1480 qdisc noop qlen 1000
    link/ipip 0.0.0.0 brd 0.0.0.0
515: eth0@if516: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
    link/ether 02:42:ac:1d:00:02 brd ff:ff:ff:ff:ff:ff
    inet 172.29.0.2/16 brd 172.29.255.255 scope global eth0
       valid_lft forever preferred_lft forever
517: eth1@if518: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
    link/ether 02:42:ac:1c:00:02 brd ff:ff:ff:ff:ff:ff
    inet 172.28.0.2/16 brd 172.28.255.255 scope global eth1
       valid_lft forever preferred_lft forever

It looks working well, but if restart the container, the interfaces order has been changed, like this:

docker restart foo

docker exec -ti foo ip a

ip info:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue 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
2: tunl0@NONE: <NOARP> mtu 1480 qdisc noop qlen 1000
    link/ipip 0.0.0.0 brd 0.0.0.0
519: eth0@if520: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
    link/ether 02:42:ac:1c:00:02 brd ff:ff:ff:ff:ff:ff
    inet 172.28.0.2/16 brd 172.28.255.255 scope global eth0
       valid_lft forever preferred_lft forever
521: eth1@if522: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue
    link/ether 02:42:ac:1d:00:02 brd ff:ff:ff:ff:ff:ff
    inet 172.29.0.2/16 brd 172.29.255.255 scope global eth1
       valid_lft forever preferred_lft forever

In addition, the default route for container has been changed too.

I would expect the networks to be assigned to interface in order and should be inconsistent after restarting container.

This PR improves network endpoints order, keep the interfaces order as it whether the container has been restarted or not.

Related issue: docker/compose#4645

[DrAuYueng]

Follows moby/libnetwork#2132.

[DrAuYueng]

Should fix #20179 as well.

[DrAuYueng]

@thaJeztah PTAL.

[hhessel]

@DrAuYueng @thaJeztah Out of personal curiosity, is there a time plan to review and merge this? Thanks

[Vlad1mir-D]

Hello? :)

[Vlad1mir-D]

Why closed?

[DrAuYueng]

Misoperation, lol.