Include docker-app plugin with docker image

[kinghuang]

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 #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.):

[ijc]

This is a sensible suggestion but I don't think it can be actioned directly here in this repo.

I think this should probably be reported against https://github.com/docker-library/docker which I think is where https://hub.docker.com/_/docker/ comes from.

[kinghuang]

Makes sense. I've opened an issue in docker-library/docker#156, and I'll close this one.

[kinghuang]

Looks like it's not going to happen on the docker image.