docker-compose config incorrectly re-formats volume source on Windows hosts.

[estenrye]

Issue

docker-compose config reformats /var/run/docker.sock as \var\run\docker.sock in the source field of the long-form volume declaration syntax. On machines running Docker For Windows with linux containers enabled, this impacts the ability to use docker-compose config to merge compose files for deploying stacks that require a bind mount to the docker daemon socket.

Steps to Reproduce ( Long-form Syntax )

stack.base.yml

version: "3.4"
services:
  traefik:
    image: traefik
    volumes:
      - type: bind
        source: /var/run/docker.sock
        target: /var/run/docker.sock
    ports:
      - target: 80
        published: 80
        protocol: tcp
        mode: ingress
      - target: 8080
        published: 8080
        protocol: tcp
        mode: ingress

stack.env.yml

version: "3.4"
services:
  traefik:
    deploy:
      mode: global
      placement:
        constraints:
          - node.role == manager
      restart_policy:
        condition: any
        delay: 5s
        max_attempts: 5
        window: 20s
      update_config:
        failure_action: rollback
        monitor: 30s
        order: start-first

execute the following commands ( Long-form Syntax )

docker-compose -f .\stack.base.yml -f .\stack.env.yml config > deploy.stack.yml
docker stack deploy -c .\deploy.stack.yml traefik
docker service ps traefik_traefik --no-trunc

Expected Output ( Long-form Syntax )

deploy.stack.yml

services:
  traefik:
    deploy:
      mode: global
      placement:
        constraints:
        - node.role == manager
      restart_policy:
        condition: any
        delay: 5s
        max_attempts: 5
        window: 20s
      update_config:
        failure_action: rollback
        monitor: 30s
        order: start-first
    image: traefik
    ports:
    - mode: ingress
      protocol: tcp
      published: 80
      target: 80
    - mode: ingress
      protocol: tcp
      published: 8080
      target: 8080
    volumes:
    - source: /var/run/docker.sock
      target: /var/run/docker.sock
      type: bind
version: '3.4'

expected output of commands:

An instance of traefik should be running on every manager instance of the swarm.

Actual Output: ( Long-form Syntax )

deploy.stack.yml

services:
  traefik:
    deploy:
      mode: global
      placement:
        constraints:
        - node.role == manager
      restart_policy:
        condition: any
        delay: 5s
        max_attempts: 5
        window: 20s
      update_config:
        failure_action: rollback
        monitor: 30s
        order: start-first
    image: traefik
    ports:
    - mode: ingress
      protocol: tcp
      published: 80
      target: 80
    - mode: ingress
      protocol: tcp
      published: 8080
      target: 8080
    volumes:
    - source: \var\run\docker.sock
      target: /var/run/docker.sock
      type: bind
version: '3.4'

Actual output from commands:

> docker service ps traefik_traefik --no-trunc
ID                          NAME                                            IMAGE                                                                                    NODE                    DESIRED STATE       CURRENT STATE                 ERROR                                                                     PORTS
idj2ik8jzkxtrhhajyw8ovj1p   traefik_traefik.hxhznlefwub35xdmjoqha1x1v       traefik:latest@sha256:d277007b55a8a8d972b1983ef11387d05f719821a2d2e23e8fa06ac5081a302f   linuxkit-00155d555a01   Ready               Rejected 3 seconds ago        "invalid mount config for type "bind": bind source path does not exist"
zrk3qwed7e4ag4zkr11k2hmy0    \_ traefik_traefik.hxhznlefwub35xdmjoqha1x1v   traefik:latest@sha256:d277007b55a8a8d972b1983ef11387d05f719821a2d2e23e8fa06ac5081a302f   linuxkit-00155d555a01   Shutdown            Rejected about a minute ago   "invalid mount config for type "bind": bind source path does not exist"
zooqyww4eprosbr77rt9ixpzl    \_ traefik_traefik.hxhznlefwub35xdmjoqha1x1v   traefik:latest@sha256:d277007b55a8a8d972b1983ef11387d05f719821a2d2e23e8fa06ac5081a302f   linuxkit-00155d555a01   Shutdown            Rejected 3 minutes ago        "invalid mount config for type "bind": bind source path does not exist"
zq9ort5zh0vc2le7dfnupmuc0    \_ traefik_traefik.hxhznlefwub35xdmjoqha1x1v   traefik:latest@sha256:d277007b55a8a8d972b1983ef11387d05f719821a2d2e23e8fa06ac5081a302f   linuxkit-00155d555a01   Shutdown            Rejected 3 minutes ago        "invalid mount config for type "bind": bind source path does not exist"
zr4sfachvinnfhkbaaqffof8t    \_ traefik_traefik.hxhznlefwub35xdmjoqha1x1v   traefik:latest@sha256:d277007b55a8a8d972b1983ef11387d05f719821a2d2e23e8fa06ac5081a302f   linuxkit-00155d555a01   Shutdown            Rejected 3 minutes ago        "invalid mount config for type "bind": bind source path does not exist"
zqaj5vl7nk05l52092zpbhrxy    \_ traefik_traefik.hxhznlefwub35xdmjoqha1x1v   traefik:latest@sha256:d277007b55a8a8d972b1983ef11387d05f719821a2d2e23e8fa06ac5081a302f   linuxkit-00155d555a01   Shutdown            Rejected 5 minutes ago        "invalid mount config for type "bind": bind source path does not exist"

Steps to Reproduce ( Short-form Syntax )

stack.base.yml

version: "3.4"
services:
  traefik:
    image: traefik
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    ports:
      - target: 80
        published: 80
        protocol: tcp
        mode: ingress
      - target: 8080
        published: 8080
        protocol: tcp
        mode: ingress

stack.env.yml

version: "3.4"
services:
  traefik:
    deploy:
      mode: global
      placement:
        constraints:
          - node.role == manager
      restart_policy:
        condition: any
        delay: 5s
        max_attempts: 5
        window: 20s
      update_config:
        failure_action: rollback
        monitor: 30s
        order: start-first

execute the following commands:

docker-compose -f .\stack.base.yml -f .\stack.env.yml config > deploy.stack.yml
docker stack deploy -c .\deploy.stack.yml traefik

Expected Output: ( Short-form Syntax )

deploy.stack.yml

services:
  traefik:
    deploy:
      mode: global
      placement:
        constraints:
        - node.role == manager
      restart_policy:
        condition: any
        delay: 5s
        max_attempts: 5
        window: 20s
      update_config:
        failure_action: rollback
        monitor: 30s
        order: start-first
    image: traefik
    ports:
    - mode: ingress
      protocol: tcp
      published: 80
      target: 80
    - mode: ingress
      protocol: tcp
      published: 8080
      target: 8080
    volumes:
    - /var/run/docker.sock:/var/run/docker.sock:rw
version: '3.4'

Expected output from commands

C:\Source> docker stack deploy -c .\deploy.stack.yml traefik
Creating network traefik_default
Creating service traefik_traefik

An instance of traefik should be running on each manger node.

Actual Output ( Short-form Syntax )

deploy.stack.yml

services:
  traefik:
    deploy:
      mode: global
      placement:
        constraints:
        - node.role == manager
      restart_policy:
        condition: any
        delay: 5s
        max_attempts: 5
        window: 20s
      update_config:
        failure_action: rollback
        monitor: 30s
        order: start-first
    image: traefik
    ports:
    - mode: ingress
      protocol: tcp
      published: 80
      target: 80
    - mode: ingress
      protocol: tcp
      published: 8080
      target: 8080
    volumes:
    - \var\run\docker.sock:/var/run/docker.sock:rw
version: '3.4'

Actual ouptut from commands:

C:\Source> docker stack deploy -c .\deploy.stack.yml traefik
Creating network traefik_default
service traefik: undefined volume "\\var\\run\\docker.sock"

Docker Version

PS C:\source> docker version
Client:
 Version:       17.12.0-ce
 API version:   1.35
 Go version:    go1.9.2
 Git commit:    c97c6d6
 Built: Wed Dec 27 20:05:22 2017
 OS/Arch:       windows/amd64

Server:
 Engine:
  Version:      17.12.0-ce
  API version:  1.35 (minimum version 1.12)
  Go version:   go1.9.2
  Git commit:   c97c6d6
  Built:        Wed Dec 27 20:12:29 2017
  OS/Arch:      linux/amd64
  Experimental: true

Docker-Compose Version

PS C:\source> docker-compose version
docker-compose version 1.19.0, build 9e633ef3
docker-py version: 2.7.0
CPython version: 2.7.14
OpenSSL version: OpenSSL 1.0.2k  26 Jan 2017

Observations

• Source field of volume long-form syntax is being reformatted to use the windows path separator \ instead of the linux path separator / specified in the compose file.
• Short-form volume syntax is also impacted with the same behavior.
• Possibly related issue: Allow linux like paths in volume source on Windows #5716

[shin-]

Thanks - let's consolidate with #5716, as this is clearly the same issue.

[shin-]

Also note that the upcoming release of Docker CE will support providing multiple files to the docker stack command, which probably takes care of that issue outright: docker/cli#569