[Container-tools] How adb and Nulecule fit together?

[Saleem Ansari]

That answers all of my questions for now. Many thanks :-)

Regards,
Saleem


----- Original Message -----
> From: "Tomas Kral" <tkral at redhat.com>
> To: "Saleem Ansari" <sansari at redhat.com>
> Cc: container-tools at redhat.com
> Sent: Thursday, February 4, 2016 4:37:04 PM
> Subject: Re: [Container-tools] How adb and Nulecule fit together?
> 
> 
> 
> On 02/04/2016 11:56 AM, Saleem Ansari wrote:
> >> Subject: Re: [Container-tools] How adb and Nulecule fit together?
> >>
> >> Hi Saleem,
> > 
> > 
> > Hi Tomas!
> > 
> > 
> >>>
> >>> Atomicapp is a reference implementation of Nulecule specification.
> >>> However
> >>> it doesn't define how to run the app itself, so I assume it is actually
> >>> Atomic that will help with this task.
> >>>
> >>> However from the project description of Atomic: "Atomic Run Tool for
> >>> installing/running/managing container images.", it doesn't say anything
> >>> specific to Atomicapp either.
> >>>
> >>
> >> Atomic is generic high-level tool for manipulating containers.
> >>
> >> Atomic allows an image provider to specify how a container image expects
> >> to be run.
> > 
> > 
> > This definitely helps me understand Atomic better. It also makes me ask
> > more questions :-)
> > 
> >  * who is "image provider" here? ( can I as a developer be considered an
> >  image provider ? )
> yes, basically whoever is building image ;-)
> 
> >  * does Atomic expect the containers to be described in a specific way?
> Depends on what you mean by described in a specific way.
> Atomic run,install and uninstall commands are using labels. If you want
> to use them you need to build images with corresponding labels.
> 
> >  * can Atomic run any existing container image or the image has to be a
> >  specific RPM based distribution?
> it can run any docker image
> 
> > 
> > I am trying to understand the base facts/assumptions that are made by
> > Atomic to work correctly.
> > 
> > 
> >> You can build build Docker image with `RUN` label where you specify
> >> command that is expected to be run to start this image.
> >> Then when you run `atomic run <yourimage>`, Atomic first inspects image,
> >> and if finds RUN label uses its value to start container.
> >>
> >> Atomic makes easier to run AtomicApp.
> >> You can run AtomicApp without atomic (see:
> >> https://github.com/projectatomic/atomicapp/blob/master/atomicapp.sh#L9)
> >> But because this is a lot of parameters, it is easier to use atomic and
> >> just do `atomic run <atomicappimage>`.
> >> Atomic than reads RUN label from image and assemble full docker run
> >> command
> >> (https://github.com/projectatomic/atomicapp/blob/master/Dockerfiles.pkgs/Dockerfile.centos#L13)
> >>
> > 
> > This example makes it super clear to me why Atomic exists. Kudos!
> > 
> >> Atomic cmd just makes running AtomicApp containers little easier that's
> >> all :-) you can run AtomicApp even without it.
> >>
> >> Hope this helps ;-)
> >>
> >>
> > 
> > 
> > Thanks!
> > 
> > Regards,
> > Saleem
> > 
>