feature: pass IPAM options at docker run

[greenpau]

Currently, when a user creates a network, the user can pass IPAM options via --ipam-opt.

However, when a user creates a container, the user cannot pass IPAM options.

docker run --help | grep ipam

In conventional/traditional networking, e.g. DHCP, a request might contain the following options.

I suggest adding the ability to pass IPAM options at docker run and make sure that the options are passed all the way to /IpamDriver.RequestAddress endpoint. This way IPAM plugin would be capable of passing a lot more information to remote IPAM servers for the servers to make IP address management decisions.

For example, --ipam-opt vnid=<id> would allow IPAM driver to notify that the IP address request have VXLAN identifier associated with it. The IPAM servers would then use that information for routing purposes.

[abhi]

@greenpau we have this PR docker/cli#317 open few months back. We can try to put it on the fast track.

[greenpau]

@greenpau we have this PR docker/cli#317 open few months back. We can try to put it on the fast track.

@abhi , that would be nice 👍

[greenpau]

@abhi , the interesting thing is in docker/libnetwork/ipams/remote/remote.go the options are being passed to the function and ultimately to a remote plugin 😄 need docker/cli plumbing 😄

// RequestAddress requests an address from the address pool
func (a *allocator) RequestAddress(poolID string, address net.IP, options map[string]string) (*net.IPNet, map[string]string, error) {
    var (
        prefAddress string
        retAddress  *net.IPNet
        err         error
    )
    if address != nil {
        prefAddress = address.String()
    }
    req := &api.RequestAddressRequest{PoolID: poolID, Address: prefAddress, Options: options}
    res := &api.RequestAddressResponse{}
    if err := a.call("RequestAddress", req, res); err != nil {
        return nil, nil, err
    }
    if res.Address != "" {
        retAddress, err = types.ParseCIDR(res.Address)
    } else {
        return nil, nil, ipamapi.ErrNoIPReturned
    }
    return retAddress, res.Data, err
}