Allow network with --config-from to be --internal

[lemrouch]

The --internal netlabel is discarded now.

Signed-off-by: Pavel Matěja [email protected]

Fix #2413

[arkodg]

@lemrouch I ran the following commands (without this patch)

~$ docker network create --config-only --subnet 192.168.22.0/24 --gateway 192.168.22.1 -o parent=eth0 --ip-range 192.168.22.32/27 dkrdev-config
7a6f0f6da870ef1cac9b1d5fb57bfa6e345c4234472c0eaa2f8e7fad3d58d855
~$ docker network create -d macvlan --scope swarm --config-from dkrdev-config --internal dkrdev
crsdyefvbtjnp5u4vhs7y1bm1
~$ docker network inspect dkrdev
[
    {
        "Name": "dkrdev",
        "Id": "crsdyefvbtjnp5u4vhs7y1bm1",
        "Created": "2019-07-11T20:59:03.817246Z",
        "Scope": "swarm",
        "Driver": "macvlan",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "",
            "Options": null,
            "Config": []
        },
        "Internal": true,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": "dkrdev-config"
        },
        "ConfigOnly": false,
        "Containers": null,
        "Options": null,
        "Labels": null
    }
]

and I can see the Internal field set to true, am I missing something ?

[arkodg]

okay you're right :), I see the issue, we override the config in applyConfigurationTo, I think inside of adding code inside NewNetwork we should edit applyConfigurationTo to skip copying over netlabel.Internal

[lemrouch]

I'm not quite sure.
There is to.generic = options.Generic{} which means not copying the netlabel.Internal will end up in missing it completelly.
We will have to check if there is some netlabel.Internal original value in to network first, then save it and reapply in such case.
This kind code there won't make much sense without context. Why would we try to save one netlabel in network class?
But I'm willing to try if you insist.

[arkodg]

applyConfigurationTo seems to be only used for ConfigFrom networks today, adding more code into the controller's NewNetwork will make it less readable .
Wouldn't something like this work in applyConfigurationTo

		for k, v := range n.generic {
                        // Skip network operator configurations
                        if k != netlabel.Internal {
			    to.generic[k] = v
                        }
		}

[lemrouch]

I'm not really familiar with golang but I think because of network.go:450 to.generic = options.Generic{} you won't have the original value of to.generic[netlabel.Internal] anymore.

[arkodg]

@lemrouch good catch, I missed that !

[arkodg]

LGTM

[arkodg]

PTAL @selansen

[selansen]

LGTM