Docker stack deploy with host network still not working

Question

I understand that some discussion in docker issue #25873 saying this is supported in 17.06 ce. I have installed 17.09 in Linux and 18.03 in Windows. Both have the same problem complaining

network "host" is declared as external, but it is not in the right scope: "local" instead of "swarm"

Would like to know why I'm not able to use the host network with scope local ? Is there a way to use host network when running docker stack deploy ?

Docker Version

Client:
 Version:       18.03.0-ce
 API version:   1.37
 Go version:    go1.9.4
 Git commit:    0520e24
 Built: Wed Mar 21 23:06:28 2018
 OS/Arch:       windows/amd64
 Experimental:  false
 Orchestrator:  swarm

Server:
 Engine:
  Version:      18.03.0-ce
  API version:  1.37 (minimum version 1.12)
  Go version:   go1.9.4
  Git commit:   0520e24
  Built:        Wed Mar 21 23:14:32 2018
  OS/Arch:      linux/amd64
  Experimental: false

Docker info

Containers: 0
 Running: 0
 Paused: 0
 Stopped: 0
Images: 1
Server Version: 18.03.0-ce
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host macvlan null overlay
 Log: awslogs fluentd gcplogs gelf journald json-file logentries splunk syslog
Swarm: active
 NodeID: cqa33vk220d3zpp9g2gqar9hd
 Is Manager: true
 ClusterID: cphphnyrr379dbm5044snxrjy
 Managers: 1
 Nodes: 1
 Orchestration:
  Task History Retention Limit: 5
 Raft:
  Snapshot Interval: 10000
  Number of Old Snapshots to Retain: 0
  Heartbeat Tick: 1
  Election Tick: 3
 Dispatcher:
  Heartbeat Period: 5 seconds
 CA Configuration:
  Expiry Duration: 3 months
  Force Rotate: 0
 Autolock Managers: false
 Root Rotation In Progress: false
 Node Address: 192.168.65.3
 Manager Addresses:
  192.168.65.3:2377
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: cfd04396dc68220d1cecbe686a6cc3aa5ce3667c
runc version: 4fc53a81fb7c994640722ac585fa9ca548971871
init version: 949e6fa
Security Options:
 seccomp
  Profile: default
Kernel Version: 4.9.87-linuxkit-aufs
Operating System: Docker for Windows
OSType: linux
Architecture: x86_64
CPUs: 2
Total Memory: 1.934GiB
Name: linuxkit-00155d006407
ID: YRXM:MKGD:7VQM:ZNK2:XKCI:DYTL:VVQH:XP5X:QRCY:CKP2:5EVJ:3QE4
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): true
 File Descriptors: 33
 Goroutines: 145
 System Time: 2018-04-08T07:24:34.2713256Z
 EventsListeners: 1
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

Docker Compose file

version: '3.4'

services:
  test:
    image: alpine
    command: top
    networks:
      - host

networks:
  host:
    external:
      name: host

Executing

C:\>docker stack deploy -c docker-compose.yml test

network "host" is declared as external, but it is not in the right scope: "local" instead of "swarm"

Answer 1

As of November Docker 18.09 release, this should work on modern Linux the same as Windows Server 2019. You can connect one service to a host port directly as well as overlay networks.

To use a host NIC directly for a published port, you don't use networks, you just change the published port mode like so:

services:
  traefik:
    image: traefik:alpine
    ports:
      - target: 80
        published: 80
        protocol: tcp
        mode: host

For normal published ports it would be mode: ingress

If you want the service to talk to overlay networks as well, you can add networks the usual way. I've got a full example of this for Traefik here.