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?
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
--
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Robert P. J. Day Ottawa, Ontario, CANADA
http://crashcourse.ca
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