[BUG] configs file "mode" option seems broken in v2.34

[julienverrecchia]

Description

When using configs in compose, a file with mode: 0555 can be made executable.

This works until v2.33.1 and gives an error in v2.34.0:

  services.<name>.configs.0.mode must be a number

Use case:

Script to wait for a Swarm service to be up (and a port to respond) before launching a process

Steps To Reproduce

Reproduced on debian.11 bullseye + ubuntu.24.04 noble

Docker CLI: 28.0.4
Docker Engine: 28.0.4
Docker compose plugin: 2.34.0 (same with docker-compose standalone v2.34.0)

Example:

configs:
  await_tcp_script:
    file: ./await/await-tcp.sh

services:
  # serviceA should respond on port 9000 before the `nginx` process starts
  serviceA:
  ...

  nginx:
    ...
    configs:
      - source: await_tcp_script
        target: /await-tcp.sh
        mode: 0555
    command:
      /await-tcp.sh 30 serviceA:9000 -- nginx
    ...

Run it as a docker stack :

docker stack deploy ...

Will fail with the error:

services.nginx.configs.0.mode must be a number

Workaround

Downgrading compose to v2.33.1 works:

# Debian
apt install docker-compose-plugin=2.33.1-1~debian.11~bullseye

# Ubuntu
apt install docker-compose-plugin=2.33.1-1~ubuntu.24.04~noble

Compose Version

$ docker compose version
Docker Compose version v2.34.0

Docker Environment

$ docker info

Client: Docker Engine - Community
 Version:    28.0.4
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.22.0
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.34.0
    Path:     /usr/libexec/docker/cli-plugins/docker-compose

Server:
 Containers: 48
  Running: 17
  Paused: 0
  Stopped: 31
 Images: 592
 Server Version: 28.0.4
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: local
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 Swarm: active
  NodeID: <id>
  Is Manager: true
  ClusterID: <id>
  Managers: 1
  Nodes: 1
  Default Address Pool: 10.136.0.0/16  
  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: <ip>
  Manager Addresses:
   <ip>:2377
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: bcc810d6b9066471b0b6fa75f557a15a1cbf31bb
 runc version: v1.2.4-0-g6c52b3f
 init version: de40ad0
 Security Options:
  apparmor
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.8.0-53-generic
 Operating System: Ubuntu 24.04.2 LTS
 OSType: linux
 Architecture: x86_64
 CPUs: 4
 Total Memory: 15.62GiB
 Name: <name>
 ID: <id>
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: false
 Insecure Registries:
  ::1/128
  127.0.0.0/8
 Live Restore Enabled: false
 Default Address Pools:
   Base: 10.134.0.0/16, Size: 24

Anything else?

Could be something I missed in the changelog or a side effect of something else..

Thanks for your work here

[ndeloof]

docker stack deploy is docker swarm, not docker compose. Separate codebase, distinct compose file parser
Please report on github.com/moby/moby

[julienverrecchia]

Well the use case uses docker stack deploy ultimately, but the issue/question is actually on docker compose config

Ex:

docker-compose -f docker-compose.yml config  | docker stack deploy $deploy_options --with-registry-auth --compose-file - stack_name

---

Let's assume a simplified compose file :

configs:
  await_tcp_script:
    file: ./await/await-tcp.sh

services:
  php:
    image: php:8.3-fpm-alpine

  nginx:
    image: nginx:1.27-alpine
    configs:
      - source: await_tcp_script
        target: /await-tcp.sh
        mode: 0555
    command:
      /await-tcp.sh 30 php:9000 -- nginx

Pre v2.34.0, docker-compose -f docker-compose.yml config

    configs:
    - source: await_tcp_script
      target: /await-tcp.sh
      mode: 365

which for some reason is accepted by docker stack deploy

In v2.34.0, docker-compose -f docker-compose.yml config

    configs:
    - source: await_tcp_script
      target: /await-tcp.sh
      mode: "0555"

which is rejected as it shouldn't be a string.

It seems to me docker compose config should output mode: 0555.

---

Temporary workaround in my case, if anyone needs it

docker-compose -f docker-compose.yml config | sed '/mode:/ s/"//g'

[ndeloof]

this has been fixed already by compose-spec/compose-go#738