Compose: creating network with defined ipam subnet is slow

[ComaVN]

Whenever I define a subnet for a network, docker-compose up is really slow, and seems to wait for ± 15 seconds on creating the network.

example config:

networks:
  default:
    ipam:
      config:
        - subnet: 172.17.0.0/28

It doesn't matter what the network is called, or what the subnet actually is, and it doesn't conflict with anything.

If I define multiple networks, creating each network takes about 15 seconds.

PoC: https://github.com/ComaVN/docker-compose-network-slow

$ docker-compose --version
docker-compose version 1.11.2, build dfed245

$ docker version
Client:
 Version:      17.09.0-ce
 API version:  1.32
 Go version:   go1.8.3
 Git commit:   afdb6d4
 Built:        Tue Sep 26 22:42:18 2017
 OS/Arch:      linux/amd64

Server:
 Version:      17.09.0-ce
 API version:  1.32 (minimum version 1.12)
 Go version:   go1.8.3
 Git commit:   afdb6d4
 Built:        Tue Sep 26 22:40:56 2017
 OS/Arch:      linux/amd64
 Experimental: false



md5-42bff5562eecd56c73c0bbc5552daf5e



$ lsb_release -a
LSB Version:    core-9.20160110ubuntu0.2-amd64:core-9.20160110ubuntu0.2-noarch:security-9.20160110ubuntu0.2-amd64:security-9.20160110ubuntu0.2-noarch
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.3 LTS
Release:    16.04
Codename:   xenial

[ComaVN]

I just noticed my docker-compose is kind of old, just retried with docker-compose version 1.16.1, build 6d1ac219, same results

[ComaVN]

Oh, and docker network create --subnet 172.17.0.0/28 testnetwork works instantly

[shin-]

Thank you for the report!
I was able to reproduce. It seems like setting the IPAM driver explicitly (driver: default) fixes the issue. Maybe we can make that the default in a future version.

[ComaVN]

That seems to work, thanks for the fast response!