Let the api to choose the default network driver.

[calavera]

That way swarm can understand the user's intention.

@tiborvass it turns out that we already have a bunch of tests in integration-cli/docker_api_network_test.go that already assume the driver is an empty string and let the daemon to select bridge as default network. I added an extra test here, but I don't think it's necessary.

Closes #17500

Signed-off-by: David Calavera david.calavera@gmail.com

[tiborvass]

@calavera that's interesting, then why wasn't it caught?

[tiborvass]

@calavera needs rebase :D #thingsgotoofast

[calavera]

Rebased, I removed the test because we have others that do the same. See:

https://github.com/docker/docker/blob/master/integration-cli/docker_api_network_test.go#L26

@tiborvass because we have a check for empty in https://github.com/docker/docker/blob/master/daemon/network.go#L91

[mavenugo]

thanks @calavera. LGTM.

I honestly don't remember why I made bridge as default at the client side.
But as you rightly spotted, it is not required.

[tiborvass]

@mavenugo it's not that it's not required, it's a bug if it's there :)

[mavenugo]

@tiborvass okay. i remember why I added it :) and it is not a bug. It was addressing this comment : #16645 (comment)

[calavera]

having the right default in the help output makes sense. I don't know how we can check who set that value 😔

[tiborvass]

@calavera if we don't already, we could have an INFO log in the daemon logs to tell which driver was selected, better than nothing.

[calavera]

Okay, I found how to solve this issue for real, yay for reading the docs!

It turns out you can detect whether a user set a flag or not with flagSet.IsSet. So, we send an empty string if the user didn't set bridge as the driver. That way swarm knows what to do with the value.

@tiborvass, @mavenugo, @vieux please, take a look.

[calavera]

These are the parameters we send to the api when I run docker network create --driver bridge foo:

Calling POST /v1.22/networks/create
form data: map["options":map[] "name":"newbridge" "check_duplicate":%!q(bool=true) "driver":"bridge" "ipam":map["driver":"default" "config":[]]]

And this is what we send when I run docker network create bar:

Calling POST /v1.22/networks/create
form data: map["options":map[] "name":"bridge2" "check_duplicate":%!q(bool=true) "driver":"" "ipam":map["driver":"default" "config":[]]]

See that when I(the user) set the driver to bridge, we send that value to the api, but we don't send anything if I don't set the driver.

Moreover, docker network create -h still shows bridge as the default option:

Usage:  docker network create [OPTIONS] NETWORK-NAME

Creates a new network with a name specified by the user

  --aux-address=map[]      auxiliary ipv4 or ipv6 addresses used by Network driver
  -d, --driver=bridge      Driver to manage the Network
  --gateway=[]             ipv4 or ipv6 Gateway for the master subnet

[vieux]

even better thanks @lgtm

[tiborvass]

@calavera nice, that's what we also do for --tls. If others are fine with this i'm fine too

[tiborvass]

LGTM

[tiborvass]

dunno what windows ci is doing, merging