Soft constraints in Docker Swarm Mode

[marcusreese]

• This is a bug report
• This is a feature request
• I searched existing issues before opening this one

Expected behavior

I would like tilde in constraint to cause Docker Swarm Mode to use the constraint if possible but deploy to another node if the specified node is not available. E.g.,

      placement:
        constraints:
        - node.hostname ==~ jetson-nano

If I am reading it correctly, this was done for Swarm Standalone/Classic in docker-archive/classicswarm#478
In Kubernetes, I believe this would be done via "preferred" (soft) nodeAffinity and weight:
https://kubernetes.io/docs/concepts/configuration/assign-pod-node/#node-affinity

Actual behavior

for ==~

value '~ jetson-nano' is invalid

or for =~

constraint expected one operator from ==, !=

I could not find docs or issues on this for version >= 1.12.

Steps to reproduce the behavior

root@Pi4-4GB-51:~# docker node ls

ID        HOSTNAME         STATUS       AVAILABILITY     MANAGER STATUS    ENGINE VERSION
oc..dv *   Pi4-4GB-51       Ready        Active           Leader            19.03.1
ul..r4     jetson-nano      Ready        Active                             18.09.2

root@Pi4-4GB-51:~# cat docker-compose.yml

version: "3.7"
services:
  submarineService:
    image: 192.168.240.51:5000/submarine
    deploy:
      placement:
        constraints:
        - node.hostname ==~ jetson-nano
    networks:
      - overlay
networks:
  overlay:

root@Pi4-4GB-51:~# docker stack deploy -c docker-compose.yml submarine-stack

Creating service submarine-stack_submarineService
failed to create service submarine-stack_submarineService: Error response from daemon: rpc error: code = Unknown desc = value '~ jetson-nano' is invalid

Output of docker version:

Client: Docker Engine - Community
 Version:           19.03.1
 API version:       1.40
 Go version:        go1.12.5
 Git commit:        74b1e89
 Built:             Thu Jul 25 21:33:17 2019
 OS/Arch:           linux/arm
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          19.03.1
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.12.5
  Git commit:       74b1e89
  Built:            Thu Jul 25 21:27:09 2019
  OS/Arch:          linux/arm
  Experimental:     false
 containerd:
  Version:          1.2.6
  GitCommit:        894b81a4b802e4eb2a91d1ce216b8817763c29fb
 runc:
  Version:          1.0.0-rc8
  GitCommit:        425e105d5a03fabd737a126ad93d62a9eeede87f
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

Output of docker info:

Client:
 Debug Mode: false

Server:
 Containers: 1
  Running: 1
  Paused: 0
  Stopped: 0
 Images: 21
 Server Version: 19.03.1
 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: oce4gvfxqz7ixv26rz97kr4wv
  Is Manager: true
  ClusterID: r1ruunzjj3ciumji4027b29pn
  Managers: 1
  Nodes: 6
  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: 192.168.240.51
  Manager Addresses:
   192.168.240.51:2377
 Runtimes: runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 894b81a4b802e4eb2a91d1ce216b8817763c29fb
 runc version: 425e105d5a03fabd737a126ad93d62a9eeede87f
 init version: fec3683
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 4.19.57-v7l+
 Operating System: Raspbian GNU/Linux 10 (buster)
 OSType: linux
 Architecture: armv7l
 CPUs: 4
 Total Memory: 3.814GiB
 Name: Pi4-4GB-51
 ID: 5D56:BMFZ:MZY2:654W:4QWJ:TLHL:6VMV:ATAP:EXTP:TBUM:HNVL:YL6T
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: http://127.0.0.1:5000
 HTTPS Proxy: http://127.0.0.1:5000
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.1:5000
  192.168.240.51:5000
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: No swap limit support
WARNING: No cpu cfs quota support
WARNING: No cpu cfs period support

Additional environment details (AWS, VirtualBox, physical, etc.)
physical (manager: Raspberry Pi 4, worker: Jetson Nano)

[yuliswe]

I’m looking for the same feature.

[Adam7288]

+1