Support to set environment variables on container-create

Registered by xianchaobo

Docker run support an option to set environment variables to a container
```
# docker run --help

    -e, --env=[] Set environment variables

Container-create in Magnum also needs this. This will help for the user to
create a container with some environment variables. Also, swarm use some
special env to scheduler.
https://github.com/docker/swarm/tree/master/scheduler/filter

Blueprint information

Status:
Complete
Approver:
Adrian Otto
Priority:
Medium
Drafter:
xianchaobo
Direction:
Approved
Assignee:
xianchaobo
Definition:
Obsolete
Series goal:
Accepted for mitaka
Implementation:
Good progress
Milestone target:
None
Started by
xianchaobo
Completed by
hongbin

Related branches

Sprints

Whiteboard

Gerrit topic: https://review.openstack.org/#q,topic:bp/support-to-set-env-variables,n,z

Addressed by: https://review.openstack.org/250696
    Add support to set env to a container

Do we need to support both: args and files?
root@devstack007:/home/gyliu# docker run --help | grep env
  -e, --env=[] Set environment variables
  --env-file=[] Read in a file of environment variables
--jay-lau-513 2015-11-28

@jaylau
I think both are needed in magnumclient. --env-file can improve user experience, it's easy for user to set a lot of envs to a container.
--jimmyxian 2015-11-28

In the Austin design summit, we decided to remove the /container endpoint. Therefore, this BP is not needed anymore. -- hongbin 2015-05-01

(?)

Work Items

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