Include docker-app plugin with docker image

[kinghuang]

Copied from docker/app#532

Description

Can the docker-app 0.8.0 CLI plugin be included with the docker 19.03 image (currently at docker:19.03.0-beta3)?

I previously asked for a docker-app image in docker/app#367, similar to the docker/compose image. But, with docker-app now functioning as a CLI plugin, it would be preferable to have it as part of the docker image.

Steps to reproduce the issue:

1. Run a container with the docker:19.03.0-beta3 image.
2. Attempt to use docker app commands.

Describe the results you received:

docker app commands aren't available. The docker-app CLI plugin is not included with the docker image.

Describe the results you expected:

Be able to use docker app commands.

Additional information you deem important (e.g. issue happens only occasionally):

There is currently no official image with Docker App, either as a plugin or as a standalone command. I need an image for CI jobs that use Docker App.

Output of docker version:

Client: Docker Engine - Community
 Version:           19.03.0-beta3
 API version:       1.40
 Go version:        go1.12.4
 Git commit:        c55e026
 Built:             Thu Apr 25 02:55:45 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Output of docker-app version:

Docker App is not available in the docker image.

Output of docker info:

N/A

Additional environment details (AWS, VirtualBox, physical, etc.):

[tianon]

This image faithfully publishes whatever bits Docker officially provides via https://download.docker.com/linux/static/ (installing necessary dependencies and some very short scripts to help with usage in minor ways).

[tianon]

To put that another way, I don't think it makes sense for us to officially bundle any additional CLI (or otherwise) plugins that Docker's standard distribution does not include (since our main goal is to be a faithful representation of Docker's upstream bits).

[kinghuang]

Ah, ok. I'll close this request and focus on asking for a docker-app image. Thanks!

[ijc]

FWIW my reading of #156 (comment) is that we should (try and) arrange for plugins to be part of https://download.docker.com/linux/static/ and then it would be possible to include them in this image. @tianon did I understand you correctly?

[tianon]

I mean, yeah, if it's intended to be part of a standard distribution of Docker, it should be included with those "standard distribution" artifacts, right? 😇 👍

IMO it's kind of strange for these to be plugins but also included by default (instead of just having a way for folks to add it easily themselves), but that's a digression. 😅

[teohhanhui]

docker/app and docker/buildx are included as plugins in docker-ce since Docker 19.03: docker/docker-ce-packaging#309

[tianon]

Sure, but from my understanding, they're still not included in the official static bundles under https://download.docker.com/linux/static/ (or else we'd already have them included, since those are the bundles we consume as-is).