[RFD] JSON output produced by --format should not prettify values

[thaJeztah]

I noticed this a couple of times, but didn't open an issue yet; when using the --format option on commands, and requesting json output, the values included in the output should output the raw values, not the formatted output as is used in other formats.

For example:

$ docker ps --format '{{json .}}' | jq . 

{
  "Command": "\"nginx -g 'daemon of…\"",
  "CreatedAt": "2017-11-07 13:30:41 +0100 CET",
  "ID": "6f02a463250c",
  "Image": "nginx:alpine",
  "Labels": "com.docker.swarm.task=,com.docker.swarm.task.id=gwbj2pzql8r6ovcyw2s61piyy,com.docker.swarm.task.name=myservice.1.gwbj2pzql8r6ovcyw2s61piyy,maintainer=NGINX Docker Maintainers <docker-maint@nginx.com>,com.docker.swarm.node.id=url9rx710g8azgnhpmpr9hqfl,com.docker.swarm.service.id=2plef0c7wdya64ball1an4u2j,com.docker.swarm.service.name=myservice",
  "LocalVolumes": "0",
  "Mounts": "",
  "Names": "myservice.1.gwbj2pzql8r6ovcyw2s61piyy",
  "Networks": "one",
  "Ports": "80/tcp",
  "RunningFor": "3 minutes ago",
  "Size": "0B",
  "Status": "Up 4 minutes"
}

The RunningFor, Size, and Status output should print the "raw" information as obtained from the container, and ID should show the un-truncated ID.

Perhaps not the best example, as RunningFor is a calculated value, but opening this for discussion.

[AkihiroSuda]

For compatibility, it might be better to add new template function like "json-raw"?

[thaJeztah]

Yes, possibly; also wondering; perhaps it's out of scope for this functionality (and people should use the API directly to get the raw information). It's just that I ran into this a couple of times, i.e. when using json, I expected to get the raw information, and it came up with "human-readable" values, packed in a JSON format.