moby: Swarm: Cannot create ingress network on Gentoo

Description I initiated a swarm manager on Gentoo. After I created some services and exposed different ports I wasn’t able to access the services through their exposed ports.

Steps to reproduce the issue:

1. docker swarm init --listen-addr 192.168.0.10:2377 --advertise-addr 192.168.0.10
2. docker service create --publish 8080:80 --name nginx nginx:alpine
3. curl -v http://192.168.0.10:8080/

Describe the results you received:

*   Trying 192.168.0.10...
* TCP_NODELAY set
* connect to 192.168.0.10 port 8080 failed: Connection refused
* Failed to connect to 192.168.0.10 port 8080: Connection refused
* Closing connection 0
curl: (7) Failed to connect to 192.168.0.10 port 8080: Connection refused

Describe the results you expected: Nginx default web-page.

Additional information you deem important (e.g. issue happens only occasionally):

Sep 26 22:09:30 homebox dockerd[25516]: time="2016-09-26T22:09:30.228569606+02:00" level=debug msg="Creating service for vip 10.255.0.3 fwMark 259 ingressPorts []*libnetwork.PortConfig{&libnetwork.PortConfig{Name: \"\",\nProtocol: 0,\nTargetPort: 0x50,\nPublishedPort: 0x1f90,\n}}"
Sep 26 22:09:30 homebox dockerd[25516]: time="2016-09-26T22:09:30+02:00" level=error msg="Failed to write to /proc/sys/net/ipv4/vs/conntrack: open /proc/sys/net/ipv4/vs/conntrack: no such file or directory"
Sep 26 22:09:30 homebox dockerd[25516]: time="2016-09-26T22:09:30.255974321+02:00" level=error msg="Failed to add firewall mark rule in sbox /var/run/docker/netns/51f6813a4c4a: reexec failed: exit status 8"
Sep 26 22:09:30 homebox dockerd[25516]: time="2016-09-26T22:09:30.256327372+02:00" level=error msg="Failed to create real server 10.255.0.4 for vip 10.255.0.3 fwmark 259 in sb ingress-sbox: no such process"

Output of docker version:

Client:
 Version:      1.12.1
 API version:  1.24
 Go version:   go1.6.3
 Git commit:   23cf638
 Built:        
 OS/Arch:      linux/amd64
 Experimental: true

Server:
 Version:      1.12.1
 API version:  1.24
 Go version:   go1.6.3
 Git commit:   23cf638
 Built:        
 OS/Arch:      linux/amd64
 Experimental: true

Output of docker info:

Containers: 0
 Running: 0
 Paused: 0
 Stopped: 0
Images: 1
Server Version: 1.12.1
Storage Driver: overlay2
 Backing Filesystem: extfs
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: null host bridge overlay
Swarm: active
 NodeID: e9lnl5lv4nm0nbtm5lyhvxgbq
 Is Manager: true
 ClusterID: 0hxwl9pho1wh5683qwl0m148y
 Managers: 1
 Nodes: 1
 Orchestration:
  Task History Retention Limit: 5
 Raft:
  Snapshot Interval: 10000
  Heartbeat Tick: 1
  Election Tick: 3
 Dispatcher:
  Heartbeat Period: 5 seconds
 CA Configuration:
  Expiry Duration: 3 months
 Node Address: 192.168.0.10
Runtimes: runc
Default Runtime: runc
Security Options: seccomp
Kernel Version: 4.4.6-gentoo
Operating System: Gentoo/Linux
OSType: linux
Architecture: x86_64
CPUs: 4
Total Memory: 7.797 GiB
Name: homebox
ID: 4BKR:NADR:E6G7:MIYY:4KTE:MUXF:RCPG:RIZJ:B2R3:T6B2:GYYJ:WYP3
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): true
 File Descriptors: 37
 Goroutines: 149
 System Time: 2016-09-26T22:35:12.571855215+02:00
 EventsListeners: 0
Registry: https://index.docker.io/v1/
Experimental: true
Insecure Registries:
 127.0.0.0/8

Additional environment details (AWS, VirtualBox, physical, etc.): Physical computer running Gentoo Linux. Linux homebox 4.4.6-gentoo #10 SMP Sat Aug 13 16:35:59 CEST 2016 x86_64 AMD Phenom(tm) II X4 945 Processor AuthenticAMD GNU/Linux