Docker completion scripts should be easier to install

[silvin-lubecki]

There is no simple and built-in way to install the completion scripts (see the bash script installation).

A better way would be to output the scripts with a docker command, like kubectl does:

$ docker completion bash
...
# install the zsh completion
$ echo "source <(docker completion zsh)" >> ~/.zshrc

[silvin-lubecki]

cc @vdemeester @thaJeztah @albers

[thaJeztah]

Don't the .deb and .rpm packages already install the completion scripts?

[albers]

Bash completion is included in the packages. Don't know about zsh.

For bash, the instructions could be simplified so that they only mention the normal plugin mechanism using the bash_completion.d directory.

There are a lot of problems associated with MacOS. It ships with horribly outdated versions of bash and bash-completion (see http://meta.ath0.com/2012/02/05/apples-great-gpl-purge/) so that every developer has to fiddle with the system to get it usable. Of course there are several ways to do this, complicating install instructions.

For these cases, a docker completion bash|zsh would be very useful.

[thaJeztah]

The difference with kubectl is that they use generated bash completion scripts (using Cobra); useful, but not always the best quality.

In our case, we'd have to figure out how to include the completion scripts in our binaries (downside: updating the bash-completion scripts can only be done if the binary is updated); perhaps similar to how we embed the Compose File schemas?

cli/cli/compose/schema/bindata.go

Line 191 in 3a8ef76

var _escData = map[string]*_escFile{

[vdemeester]

It would also allow to quickly test the completion by just compiling the binary from the PR 😛

@thaJeztah yes that's more or less what @silvin-lubecki and I were thinking, embedding the completions script into the binary 👼

[albers]

This would aslo be a very handy for docker-compose and docker-machine, too. As they do not have packages, installing the completions always involves separate downloads.
This could be as easy as docker-compose completion bash > /etc/bash_completion.d/docker-compose.

[thaJeztah]

Even more awesome; publish updated versions as images on Docker Hub (default version embedded);

docker completion update --component=compose > /etc/bash_completion.d/docker-compose

🤔

[silvin-lubecki]

I filled this issue when I was trying to test the new bash completion on docker stack deploy, and it was really painful... It would ease testing and also make life easier for users with their own built cli, I guess.

[albers]

@silvin-lubecki I'm very sorry for that.

[silvin-lubecki]

Lol don't be, it's none of your fault 😉

[ryankemper]

Are there any plans to work on this?

I want simple docker completion zsh, docker completion bash commands so I can source the commands in my config. The existing options are to submodule the entire docker cli repo (really, really bad) or manually curl the completion file and stick it in .zsh/completion (better, but still bad).

Sure, I could write a script to idempotently put the completion file it grabs over https in the right spot, but that's a lot of hassle and I still can't easily track the updates from master without running the script every X minutes. It'd be much more elegant to have the completion command natively.

[thaJeztah]

@ryankemper wondering; how did you install docker? Is this on Linux or Windows/Mac?

The .deb and .rpm packages should install the completion scripts;

https://github.com/docker/docker-ce-packaging/blob/a119f42ef86517dc79e0b3749acdb457a63dea6d/rpm/SPECS/docker-ce-cli.spec#L64-L70

https://github.com/docker/docker-ce-packaging/blob/a119f42ef86517dc79e0b3749acdb457a63dea6d/deb/common/rules#L20-L29

[ryankemper]

@thaJeztah I installed on macos, so I think that involved actually installing a dmg since I haven't found a brew command to do so.

However, I maintain my dotfiles as cross-platform and idempotent, so I would like to be able to always access the completion script natively via a command as long as Docker is installed. That way I don't have to have separate arch linux, macos, fedora, etc install commands; I tend to use a number of different *nix based OS in different contexts so it's important for me to have the most simple system possible.

I'd be willing to try implementing the docker completion $SHELL command myself, but I'll be pretty busy throughout the next few days so I might not be able to start in earnest for a while.

[Thanks for the quick response and the package links, by the way. In the interim, I'm just going to curl the file and manually source it in my config]