name ignored on networks when using docker stack deploy

[tim3trick]

Description
I have the following yml (foo.yml):

version: "3.8"
services:
  dummy:
    image: hello-world
    networks:
      - network1-${TICKET}
networks:
  network1-${TICKET}:
    driver: overlay
    name: network1-${TICKET}

TICKET = "latest" (set either via portainer, or $ export TICKET=latest)
But docker stack deploy --compose-file=foo.yml foo leads to:

Creating network foo_network1-latest
service dummy: undefined network "network1-latest"

Steps to reproduce the issue:

1. Use the yml provided

Describe the results you received:

Creating network foo_network1-latest
service dummy: undefined network "network1-latest"

Describe the results you expected:

Creating network network1-latest
Creating service foo_dummy"

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

Output of docker version:

Client: Docker Engine - Community
 Version:           19.03.13
 API version:       1.40
 Go version:        go1.13.15
 Git commit:        4484c46d9d
 Built:             Wed Sep 16 17:02:55 2020
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          19.03.13
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.13.15
  Git commit:       4484c46d9d
  Built:            Wed Sep 16 17:01:25 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.3.7
  GitCommit:        8fba4e9a7d01810a393d5d25a3621dc101981175
 runc:
  Version:          1.0.0-rc10
  GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

Output of docker info:

Client:
 Debug Mode: false

Server:
 Containers: 5
  Running: 3
  Paused: 0
  Stopped: 2
 Images: 18
 Server Version: 19.03.13
 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 ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: active
  NodeID: *******
  Is Manager: true
  ClusterID: *******
  Managers: 1
  Nodes: 5
  Default Address Pool: 10.0.0.0/8  
  SubnetSize: 24
  Data Path Port: 4789
  Orchestration:
   Task History Retention Limit: 5
  Raft:
   Snapshot Interval: 10000
   Number of Old Snapshots to Retain: 0
   Heartbeat Tick: 1
   Election Tick: 10
  Dispatcher:
   Heartbeat Period: 5 seconds
  CA Configuration:
   Expiry Duration: 3 months
   Force Rotate: 0
  Autolock Managers: false
  Root Rotation In Progress: false
  Node Address: *******
  Manager Addresses:
   *******:2377
 Runtimes: runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 8fba4e9a7d01810a393d5d25a3621dc101981175
 runc version: dc9208a3303feef5b3839f4323d9beb36df0a9dd
 init version: fec3683
 Security Options:
  apparmor
  seccomp
   Profile: default
 Kernel Version: 4.19.0-10-amd64
 Operating System: Debian GNU/Linux 10 (buster)
 OSType: linux
 Architecture: x86_64
 CPUs: 16
 Total Memory: 62.84GiB
 Name: swarm01
 ID: U6J4:FJC2:OG6D:GXOY:JOSM:2RYX:OU3A:FORA:37TU:2X4D:3JTC:V3XK
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: No swap limit support

Additional environment details (AWS, VirtualBox, physical, etc.):
docker is installed natively as described in the docs

[SMFloris]

Hello @tim3trick,

The issue lies with the interpolation of the file.

Running: docker-compose -f ./foo.yml config gives us:

networks:
  network1-$${TICKET}:
    driver: overlay
    name: network1-latest
services:
  dummy:
    image: hello-world
    networks:
      network1-latest: null
version: '3.8'

That is why docker stack cannot actually find that network. You should probably find an alternative because it seems interpolation of env variables in key names such as networks is not possible.

P.S. this is also a good use-case for #2740

[thaJeztah]

closing, as this went stale