Re: process supervisor - considerations for docker

From: John Regan <john_at_jrjrtech.com>
Date: Sun, 1 Mar 2015 11:27:56 -0600

Hi all -

Dreamcat4,
I think I got muddled up a few emails ago and didn't realize what you
were getting at. An easy-to-use, "extract this and now you're cooking
with gas" type tarball that works for any distro is an awesome idea!
My apologies for misunderstanding your idea.

The one "con" I foresee (if you can really call it that) you can't
list just a tarball on the Docker Hub. Would it be worth coming up
with a sort of "flagship image" that makes use of this? I guess we
could just start using it in our own images? In the end, it's not a
big deal - just thought it'd be worth figuring out how to maximize
exposure.

Laurent, Gorka, and Dreamcat4: this is awesome. :)

-John

On Sun, Mar 01, 2015 at 10:13:24AM +0100, Gorka Lertxundi wrote:
> Hi guys,
>
> I haven't had much time this week due to work and now I am overwhelmed!
>
> Yesterday, as Dreamcat4 has noticed, I've been working in a version that
> gathers all the ideas covered here.
>
> All,
> * I already converted bash init scripts into execline and make use of
> s6-utils instead of 'linux' ones to facilitate usage in another base images.
> * It's important to have just _one_ codebase, this would help focusing
> improvements and problems in one place. I extracted all the elements I
> thought would be useful in a container environment. So, if you all feel
> comfortable we could start discussing bugs, improvements or whatever there.
> I called this project/repo container-s6-overlay-builder (
> https://github.com/glerchundi/container-s6-overlay-builder).
> * Now, and after abstracting 's6-overlay', using ubuntu with s6 is a matter
> of extracting a tarball. container-base is using it already:
> https://github.com/glerchundi/container-base/blob/master/Dockerfile#L73-L75.
> * To sum up, we all agree with this. It is already implemented in the
> overlay:
> - Case #1: Common case, start supervision tree up.
> docker run image
> - Case #2: Would start a shell without the supervision tree running
> docker run -ti --entrypoint="" base /bin/sh
> - Case #3: Would start a shell with the supervision tree up.
> docker run -ti image /bin/sh
>
> Dreamcat4,
> * Having a tarball with all the needed base elements to get s6 working is
> the way to go!
>
> Laurent,
> * Having a github mirror repo is gonna help spreading the word!
> * Although three init phases are working now I need your help with those
> scripts, probably a lot of mistakes were done...
> -
> https://github.com/glerchundi/container-s6-overlay-builder/tree/master/rootfs/etc/s6/.s6-init/init-stage1
> -
> https://github.com/glerchundi/container-s6-overlay-builder/tree/master/rootfs/etc/s6/.s6-init/init-stage2
> -
> https://github.com/glerchundi/container-s6-overlay-builder/tree/master/rootfs/etc/s6/.s6-init/init-stage3
> * I've chosen /etc/s6/.s6-init as the destination folder for the init
> scripts, would you like me to change?
>
> John,
> About github organization, I think this is not the place to discuss about
> it. I really like the idea and I'm open to discuss it but first things
> first, lets focus on finishing this first approach! Still, simple-d and
> micro-d are good names but are tightly coupled to docker *-d, and rocket
> being the relatively the new buzzword (kubernetes is going to support it)
> maybe we need to reconsider them.
>
> rgds,
>
> 2015-02-28 18:57 GMT+01:00 John Regan <john_at_jrjrtech.com>:
>
> > Sweet. And yeah, as Laurent mentioned in the other email, it's the
> > weekend. Setting dates for this kind of stuff is hard to do, I just
> > work on this in my free time. It's done when it's done.
> >
> > I also agree that s6 is *not* a docker-specific tool, nor should it
> > be. I'm thankful that Laurent's willing to listen to any ideas we
> > might have re: s6 development, but like I said, the goal is *not*
> > "make s6 a docker-specific tool"
> >
> > There's still a few high-level decisions to be made, too, before we
> > really start any work:
> >
> > 1. Goals:
> > * Are we going to make a series of s6 baseimages (like one
> > based on Ubuntu, another on CentOS, Alpine, and so on)?
> > * Should we pick a base distro and focus on creating a series of
> > platform-oriented images, aimed more at developers (ie, a PHP image, a
> > NodeJS image, etc)?
> > * Or should be focus on creating a series of service-oriented
> > images, ie, an image for running GitLab, an image for running an
> > XMPP server, etc?
> >
> > Figuring out the overall, high-level focus early will be really
> > helpful in the long run.
> >
> > Options 2 and 3 are somewhat related - you can't really get to 3
> > (create service-oriented images) without getting through 2 (make
> > platform-oriented images) anyway.
> >
> > It's not like a goal would be set in stone, either. If more guys want
> > to get on board and help, we could alway sit down and re-evaluate.
> > With more manpower, you could get into doing a whole series of
> > distro-based, service-oriented images (ie, a Ubuntu XMPP server as
> > well as an Alpine XMPP server).
> >
> > But given we're just a few guys, setting a straightforward small focus
> > is probably the way to go. I would vote for either creating a series
> > of baseimages, oriented towards other image-makers, or pick Alpine as
> > a base, and focus on making small and efficient service-oriented
> > images (ie, a 10MB XMPP service, something like that) aimed at
> > sysadmins/users.
> >
> > But I'm open to any of those options, or others, so long as it's
> > within the realm of possibility for just a few people working in their
> > free time.
> >
> > 1. Should be form a GitHub org, and what should it be called?
> >
> > I vote yes, I'll go ahead and make it if you want.
> >
> > For the org name, I was thinking about starting a series of Alpine
> > images aimed at users (like I said, 10MB chat service) under the org
> > name "micro-d" (as in, Micro Docker containers), already. If that's the
> > focus we go with, then that's probably a pretty OK name.
> >
> > If we go with doing a series of simple, easy-to-use baseimages aimed
> > at other imagemakers, then probably something like "simple-d" (Simple
> > Docker containers).
> >
> > Again, open to suggestions, those are just my initial ideas. The one
> > thing I would advise against is using s6 in the name, since that
> > would imply it's a project under the skarnet.org umbrella, which I
> > don't think this is. It's outside that scope. We can promote how much
> > we love s6 all we want in the docs, and blog posts, and so on, but
> > we *shouldn't* do things like call our init "s6-init", name the image
> > "s6-alpine", stuff like that.
> >
> > Once we figure out the high-level goals, we can set out a few more
> > structural-type things.
> >
> > -John
> >
Received on Sun Mar 01 2015 - 17:27:56 UTC

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