fedora-dockerfiles: "LABEL" lines in cockpit-ws sample file look weird

[Daniel J Walsh]

Here are a couple of blogs on the atomic command

http://developerblog.redhat.com/2015/04/21/introducing-the-atomic-command/
http://www.projectatomic.io/blog/2015/04/using-environment-substitution-with-the-atomic-command/

atomic command is available for both fedora and fedora atomic host.

On 08/10/2015 08:43 AM, Daniel J Walsh wrote:
>
> On 08/10/2015 08:31 AM, Robert P. J. Day wrote:
>> On Mon, 10 Aug 2015, Daniel J Walsh wrote:
>>
>>> On 08/10/2015 05:43 AM, Robert P. J. Day wrote:
>>>>   brief digression from my discussion of docker roadmap and stuff like
>>>> that ... i'm using the sample Dockerfiles from the
>>>> "fedora-dockerfiles" package to demonstrate various Dockerfile
>>>> instructions in an upcoming course, and i ran across this:
>>>>
>>>> cockpit-ws/Dockerfile:LABEL INSTALL /usr/bin/docker run -ti --rm --privileged -v /:/host IMAGE /container/atomic-install
>>>> cockpit-ws/Dockerfile:LABEL UNINSTALL /usr/bin/docker run -ti --rm --privileged -v /:/host IMAGE /cockpit/atomic-uninstall
>>>> cockpit-ws/Dockerfile:LABEL RUN /usr/bin/docker run -d --privileged --pid=host -v /:/host IMAGE /container/atomic-run --local-ssh
>>>>
>>>> i have no idea what those lines mean, they don't even seem valid as
>>>> the documentation suggests the proper form of a Dockerfile LABEL
>>>> instruction requires an "=" sign.
>>>>
>>>>   what does the above mean, if anything?
>>>>
>>>> rday
>>>>
>>> I think the = sign is optional.
>>   ah, "man Dockerfile" doesn't mention that -- bugzilla time?
>>
>>> Although I would prefer it in the form of
>>>
>>> LABEL INSTALL="/usr/bin/docker run -ti --rm --privileged -v /:/host IMAGE /container/atomic-install"
>>   as would i. by the way, i'm assuming there's nothing magical about
>> the labels INSTALL, UNINSTALL or RUN, right? they're simply being
>> added as metadata to the image as documentation that someone can dig
>> out later with "docker inspect"? beyond that, they have no special
>> power, is that correct?
> The special power it the "atomic run|install|uninstall" command will
> automatically use them
>
> atomic install cockpit-ws
>
> Does a
>
> docker pull cockpit-ws
>
> Then docker inspect to get the INSTALL label,
> then it executes the INSTALL label substituting environment variables
> like ${NAME} and ${IMAGE}
>
> Do a man atomic.
>
>>> And with the latest atomic we now support
>>>
>>> LABEL INSTALL="/usr/bin/docker run -ti --rm --privileged -v /:/host \${IMAGE} /container/atomic-install"
>>   just to clarify these two uses of IMAGE, the first one will simply
>> keep the literal string "IMAGE", correct? while the second will use
>> escaping so that the label saved will incorporate the literal string
>> "$(IMAGE}" -- i'm assuming to show the reader that that is supposed to
>> represent an image name?
>>
>> rday
>>
> No in either case IMAGE will be substituted with the image specified on the
> atomic install command.
>
>