Help message for "docker swarm init" shows text of "docker init"

[Radiergummi]

Description

When attempting to read the help text for swarm init using docker swarm init --help, the CLI will show the following output:

docker swarm init --help

Usage:  docker [OPTIONS] COMMAND

docker-init is a Docker CLI plugin

Commands:
  init                       Docker Init

Global Options:
      --config string      Location of client config files (default "/Users/moritz/.docker")
  -c, --context string     Name of the context to use to connect to the daemon (overrides DOCKER_HOST env var and default context set with "docker context use")
  -D, --debug              Enable debug mode
  -H, --host list          Daemon socket(s) to connect to
  -l, --log-level string   Set the logging level ("debug", "info", "warn", "error", "fatal") (default "info")
      --tls                Use TLS; implied by --tlsverify
      --tlscacert string   Trust certs signed only by this CA (default "/Users/moritz/.docker/ca.pem")
      --tlscert string     Path to TLS certificate file (default "/Users/moritz/.docker/cert.pem")
      --tlskey string      Path to TLS key file (default "/Users/moritz/.docker/key.pem")
      --tlsverify          Use TLS and verify the remote

Run 'docker COMMAND --help' for more information on a command.

For more help on how to use Docker, head to https://docs.docker.com/go/guides/

Reproduce

1. Call docker swarm init --help

Expected behavior

It should show the swarm init help text; I needed the reference for address advertisement.

docker version

Client:
 Cloud integration: v1.0.35
 Version:           24.0.2
 API version:       1.43
 Go version:        go1.20.4
 Git commit:        cb74dfc
 Built:             Thu May 25 21:51:16 2023
 OS/Arch:           darwin/amd64
 Context:           desktop-linux

Server: Docker Desktop 4.21.1 (114176)
 Engine:
  Version:          24.0.2
  API version:      1.43 (minimum version 1.12)
  Go version:       go1.20.4
  Git commit:       659604f
  Built:            Thu May 25 21:52:17 2023
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.21
  GitCommit:        3dce8eb055cbb6872793272b4f20ed16117344f8
 runc:
  Version:          1.1.7
  GitCommit:        v1.1.7-0-g860f061
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info

Client:
 Version:    24.0.2
 Context:    desktop-linux
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.11.0
    Path:     /Users/moritz/.docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.19.1
    Path:     /Users/moritz/.docker/cli-plugins/docker-compose
  dev: Docker Dev Environments (Docker Inc.)
    Version:  v0.1.0
    Path:     /Users/moritz/.docker/cli-plugins/docker-dev
  extension: Manages Docker extensions (Docker Inc.)
    Version:  v0.2.20
    Path:     /Users/moritz/.docker/cli-plugins/docker-extension
  init: Creates Docker-related starter files for your project (Docker Inc.)
    Version:  v0.1.0-beta.6
    Path:     /Users/moritz/.docker/cli-plugins/docker-init
  sbom: View the packaged-based Software Bill Of Materials (SBOM) for an image (Anchore Inc.)
    Version:  0.6.0
    Path:     /Users/moritz/.docker/cli-plugins/docker-sbom
  scan: Docker Scan (Docker Inc.)
    Version:  v0.26.0
    Path:     /Users/moritz/.docker/cli-plugins/docker-scan
  scout: Command line tool for Docker Scout (Docker Inc.)
    Version:  0.16.1
    Path:     /Users/moritz/.docker/cli-plugins/docker-scout

Server:
 Containers: 8
  Running: 7
  Paused: 0
  Stopped: 1
 Images: 49
 Server Version: 24.0.2
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 2
 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: swb1uxtvrc222v3pnatozs5vy
  Is Manager: true
  ClusterID: dkf4zgwrhtk7399yisy2xtzk1
  Managers: 1
  Nodes: 1
  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: 192.168.65.4
  Manager Addresses:
   192.168.65.4:2377
 Runtimes: io.containerd.runc.v2 runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 3dce8eb055cbb6872793272b4f20ed16117344f8
 runc version: v1.1.7-0-g860f061
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 5.15.49-linuxkit-pr
 Operating System: Docker Desktop
 OSType: linux
 Architecture: x86_64
 CPUs: 6
 Total Memory: 7.772GiB
 Name: docker-desktop
 ID: 7ec1dcd4-5229-4cf8-9f79-8596deb0c066
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: http.docker.internal:3128
 HTTPS Proxy: http.docker.internal:3128
 No Proxy: hubproxy.docker.internal
 Experimental: false
 Insecure Registries:
  hubproxy.docker.internal:5555
  127.0.0.0/8
 Live Restore Enabled: false

Additional Info

No response

[hernandanielg]

Bug confirmed on Mac - I'm taking a look and giving this a shot for a PR ;)

[hernandanielg]

I've been working on this one and using dlv debugger in VScode found that the issue is that helpFunc is nil for both docker swarm and docker swarm init commands

So it falls recursevely into HelpFunc() function from spf13/cobra
https://github.com/spf13/cobra/blob/main/command.go#L444

Finally it calls help function from its father's parent command wich is docker with the arguments init so that's why help output is so weird if you compare it with the normal docker --help output...

I'm still trying to figure out how to fix it - if you or anyone has some ideas let us know...

[hernandanielg]

Forget what I said before - I was wrong

Found the issue.

During the execution of the newDockerCommand() function, sets help function for the command by calling setHelpFunc()
https://github.com/docker/cli/blob/master/cmd/docker/docker.go#L63

On this function checks if the command is a docker plugin and executes plugin help, it happens that command name is init as we can observe using dlv

➜  call cmd.Name()
"init"
➜  cmd.Use
"init [OPTIONS]"

Due to this, on manager.go evaluates NamePrefix + name (const NamePrefix = 'docker-') so it becomes docker-init

At the end executes the plugin executable binary along with the arguments, thus the output:

➜  /path/to/cli-plugins/docker-init swarm init --help

Usage:  docker [OPTIONS] COMMAND

docker-init is a Docker CLI plugin

Commands:
  init                       Docker Init

Global Options:
      --config string      Location of client config files (default "/Users/hernandanielg/.docker")
  -c, --context string     Name of the context to use to connect to the daemon (overrides DOCKER_HOST env var and default context set with "docker context use")
  -D, --debug              Enable debug mode
  -H, --host list          Daemon socket(s) to connect to
  -l, --log-level string   Set the logging level ("debug", "info", "warn", "error", "fatal") (default "info")
      --tls                Use TLS; implied by --tlsverify
      --tlscacert string   Trust certs signed only by this CA (default "/Users/hernandanielg/.docker/ca.pem")
      --tlscert string     Path to TLS certificate file (default "/Users/hernandanielg/.docker/cert.pem")
      --tlskey string      Path to TLS key file (default "/Users/hernandanielg/.docker/key.pem")
      --tlsverify          Use TLS and verify the remote

Run 'docker COMMAND --help' for more information on a command.

For more help on how to use Docker, head to https://docs.docker.com/go/guides/

Will work tomorrow on preventing namesake docker plugins for a given command and prepare a PR (bear with me 3am here)