Add bash completion for available plugins

[crazy-max]

closes#4089

- What I did

This is a follow-up of #4089 (comment) to enable bash completion for available plugins.

- How I did it

- How to verify it

$ mkdir -p ~/.local/share/bash-completion/completions
$ cp ./contrib/completion/bash/docker ~/.local/share/bash-completion/completions/docker
$ _completion_loader docker
$ docker info --format '{{json .ClientInfo.Plugins}}' | jq
[
{
"SchemaVersion": "0.1.0",
"Vendor": "Docker Inc.",
"Version": "v0.10.0-rc2-175-g00bb9c5c.m",
"ShortDescription": "Docker Buildx",
"Name": "buildx",
"Path": "/home/crazy/.docker/cli-plugins/docker-buildx",
"ShadowedPaths": [
"/usr/libexec/docker/cli-plugins/docker-buildx"
]
},
{
"SchemaVersion": "0.1.0",
"Vendor": "Docker Inc.",
"Version": "v2.16.0",
"ShortDescription": "Docker Compose",
"Name": "compose",
"Path": "/usr/libexec/docker/cli-plugins/docker-compose"
},
{
"SchemaVersion": "0.1.0",
"Vendor": "Docker Inc.",
"Version": "v0.23.0",
"ShortDescription": "Docker Scan",
"Name": "scan",
"Path": "/usr/libexec/docker/cli-plugins/docker-scan"
}
]
$ docker build [tab][tab]
build builder buildx
$ docker buildx [tab][tab]
bake create help inspect prune stop version build du imagetools ls rm use
$ docker buildx b [tab][tab]
bake build
$ docker co [tab][tab]
commit compose config container context
$ docker compose [tab][tab]
build cp down exec kill ls port pull restart run stop unpause version config create events images logs pause ps push rm start top up

To make it works with buildx plugin you need docker/buildx#1674

- Description for the changelog

- A picture of a cute animal (not mandatory but encouraged)

cc @silvin-lubecki@ulyssessouza

[silvin-lubecki]

Not a shell script expert here, but the logic looks good 👍

[albers]

This is really, really cool.

I have to admit that I do not fully understand __docker_complete_plugin() but I assume this is basically an idiom for cobra generated completions and should be correct.

I did not find any issues with the completions.

Thanks @crazy-max.

[crazy-max]

@albers Thanks for the review. I made the suggested changed.

I think in follow-up we could use the same logic but for all docker commands so we would only need a single function to handle completion like the __docker_complete_plugin() one does.

I also have a branch to handle this for fish and zsh.

e.g., for fish:

# plugins
set PLUGINS_PATH (docker info --format '{{range .ClientInfo.Plugins}}{{.Path}},{{end}}')
function __fish_docker_plugin_complete --description 'Print plugins commands and subcomands' -a plugin_path
set -l resultArray $plugin_path "__completeNoDesc"
for i in (commandline -opc)
if set -q i
set -a resultArray "''"
else
set -a resultArray $i
end
end
set -l result (eval printf '%s ' $resultArray 2> /dev/null | grep -v '^:[0-9]*$')
if set -q i
return 1
end
echo $result
return 0
end
for plugin_path in (string split ',' $PLUGINS_PATH)
set plugin_name (string trim $plugin_path)
set plugin_name (string trim -l 'docker-' $plugin_name)
set plugin_name (echo $plugin_name | sed 's/\.[^.]*$//')
complete -c docker -f -n '__fish_docker_no_subcommand' -a $plugin_name
complete -c docker -A -f -n "__fish_seen_subcommand_from $plugin_name" -a "(__fish_docker_plugin_complete $plugin_path)"
end

Not tested and needs more work I think. I'm not an expert of this shell 😅.

[codecov-commenter]

Codecov Report

Merging #4094 (aa0aa4a) into master (cb5463a) will decrease coverage by 0.02%.
The diff coverage is n/a.

Additional details and impacted files

@@ Coverage Diff @@## master #4094 +/- ##
==========================================
- Coverage 59.15% 59.13% -0.02% 
==========================================
Files 285 285 Lines 24725 24738 +13 ==========================================
+ Hits 14627 14630 +3 - Misses 9212 9221 +9 - Partials 886 887 +1 

[albers]

Thanks @crazy-max. Very impressive.

[crazy-max]

PTAL @thaJeztah@vvoland 🙏

[vvoland]

Just tested and it seems to work perfectly, thanks!

[ulyssessouza]

LGTM! 🥳

[thaJeztah]

LGTM