Fix internal macvlan network to work in swarm

[lemrouch]

Using dummy interface allows communication beween containers only if
they are running on the same node in swam.

Signed-off-by: Pavel Matěja pavel@verotel.cz

[GordonTheTurtle]

Please sign your commits following these rules:
https://github.com/moby/moby/blob/master/CONTRIBUTING.md#sign-your-work
The easiest way to do this is to amend the last commit:

$ git clone -b "2418-fix" git@github.com:lemrouch/libnetwork.git somewhere
$ cd somewhere
$ git rebase -i HEAD~842357810328
editor opens
change each 'pick' to 'edit'
save the file and quit
$ git commit --amend -s --no-edit
$ git rebase --continue # and repeat the amend for each commit
$ git push -f

Amending updates the existing PR. You DO NOT need to open a new one.

[selansen]

can you sign the commit with above instruction?

[lemrouch]

can you sign the commit with above instruction?

Hi, my impression was dco-signed — All commits are signed and All checks have passed means it's already done.
BTW: those instructions dont work.

[selansen]

you need to amend commit with -s option. I think that is what expected from the above message. if you have already done it, not sure why we received 'sing your commit' messages.

[lemrouch]

you need to amend commit with -s option. I think that is what expected from the above message. if you have already done it, not sure why we received 'sing your commit' messages.

There was unsigned merge fixed by:
"lemrouch force-pushed the lemrouch:2418-fix branch from c7203f1 to da39847 5 days ago"
It should be all OK now.

[lemrouch]

What can I do to get this commit merged?

[arkodg]

@lemrouch if the intent of this PR is to separate the notion of empty parent to create a dummy interface vs making sure internal networks can communicate in swarm, there might be more plumbing involved
https://github.com/docker/libnetwork/blob/da39847dba735007c79e104d53d4133616d5b00b/drivers/macvlan/macvlan_network.go#L65
and
https://github.com/docker/libnetwork/blob/da39847dba735007c79e104d53d4133616d5b00b/drivers/macvlan/macvlan_network.go#L93

[lemrouch]

@arkodg intent is described in #2418 therefore I didn't really care about empty parent in other code paths as I have non-empty one filled by config-only network and all my MACVLAN networks are internal.
What do you suggest in other cases?

[arkodg]

I see so both the above code flows are redundant for your case ( config-from networks ), have you tested these changes out ? Can you please share a working example

[lemrouch]

Yes, I have tested them in combination with #2407
but I don't have access to the system right now. I hope I can provide example in a week or so.

[arkodg]

Thanks, please share a snippet of the working commands when possible

[lemrouch]

Example is in #2418
It assumes fix for default gateway as well.

[lemrouch]

About lines 65 and 93 mentioned above:
I think someone can try the same thing with internal MACVLAN IPv6 only network.
As he would have same parent interfaces on all nodes and no need for IPv4 network split he would not need config-only networks.
But those lines are for nonexistent and empty parent so this fix should be enough. Am I correct?

[arkodg]

LGTM , thanks for sharing the working example in #2418 (comment)
ptal @selansen

[lemrouch]

Thanks!
Can you check #2407 for me as well as those are both required for this to work?

[arkodg]

also do we need a similar change for ipvlan ?

[lemrouch]

Frankly I don't know. I have not read nor tried that code. I can check it on Monday.

[selansen]

LGTM

[arkodg]

@lemrouch can you please make similar changes in https://github.com/docker/libnetwork/blob/6659f7f4d8c1ec7a412a33f8973423ad38d22982/drivers/ipvlan/ipvlan_network.go#L197

[arkodg]

thanks, will merge on green

[lemrouch]

Do you know what went wrong? I'm not familiar with your tests.

[arkodg]

can you please rebase to the latest master, we fixed a bunch of flaky tests a while back

[arkodg]

git remote add upstream git@github.com:docker/libnetwork.git
git checkout master
git merge upstream/master
git checkout 2418-fix
git rebase master