Open Stack

I don’t think it is a good to re-invent docker-compose in Higgins. Instead, we should leverage existing libraries/tools if we can.

Frankly, I don’t think Higgins should interpret any docker-compose like DSL in server, but maybe it is a good idea to have a CLI extension to interpret specific DSL and translate it to a set of REST API calls to Higgins server. The solution should be generic enough so that we can re-use it to interpret another DSL (e.g. pod, TOSCA, etc.) in the future.

Best regards,
Hongbin

From: Denis Makogon [mailto:lildee1991 at gmail.com]
Sent: May-31-16 3:25 PM
To: OpenStack Development Mailing List (not for usage questions)
Subject: Re: [openstack-dev] [higgins] Docker-compose support

Hello.

It is hard to tell if given API will be final version, but i tried to make it similar to CLI and its capabilities. So, why not?

2016-05-31 22:02 GMT+03:00 Joshua Harlow <harlowja at fastmail.com<mailto:harlowja at fastmail.com>>:
Cool good to know,

I see https://github.com/docker/compose/pull/3535/files#diff-1d1516ea1e61cd8b44d000c578bbd0beR66

Would that be the primary API? Hard to tell what is the API there actually, haha. Is it the run() method?

I was thinking more along the line that higgins could be a 'interpreter' of the same docker-compose format (or similar format); if the library that is being created takes a docker-compose file and turns it into a 'intermediate' version/format that'd be cool. The compiled version would then be 'executable' (and introspectable to) by say higgins (which could say traverse over that intermediate version and activate its own code to turn the intermediate versions primitives into reality), or a docker-compose service could or ...

What abou TOSCA? From my own perspective compose format is too limited, so it is really necessary to consider regarding use of TOSCA in Higgins workflows.


Libcompose also seems to be targeted at a higher level library, from at least reading the summary, neither seem to be taking a compose yaml file, turning it into a intermediate format, exposing that intermediate format to others for introspection/execution (and also likely providing a default execution engine that understands that format) but instead both just provide an equivalent of:

That's why i've started this thread, as community we have use cases for Higgins itself and for compose but most of them are not formalized or even written. Isn't this a good time to define them?

  project = make_project(yaml_file)
  project.run/up()

Which probably isn't the best API for something like a web-service that uses that same library to have. IMHO having a long running run() method

Well, compose allows to run detached executions for most of its API calls. By use of events, we can track service/containers statuses (but it is not really trivial).

exposed, without the necessary state tracking, ability to interrupt/pause/resume that run() method and such is not going to end well for users of that lib (especially a web-service that needs to periodically be `service webservice stop` or restart, or ...).

Yes, agreed. But docker or swarm by itself doesn't provide such API (can't tell the same for K8t).

Denis Makogon wrote:
Hello Stackers.


As part of discussions around what Higgins is and what its mission there
are were couple of you who mentioned docker-compose [1] and necessity of
doing the same thing for Higgins but from scratch.

I don't think that going that direction is the best way to spend
development cycles. So, that's why i ask you to take a look at recent
patchset submitted to docker-compose upstream [2] that makes this tool
(initially designed as CLI) to become a library with Python API.  The
whole idea is to make docker-compose look similar to libcompose [3]
(written on Go).

If we need to utilize docker-compose features in Higgins i'd recommend
to work on this with Docker community and convince them to land that
patch to upstream.

If you have any questions, please let me know.

[1] https://docs.docker.com/compose/
[2] https://github.com/docker/compose/pull/3535
[3] https://github.com/docker/libcompose


Kind regards,
Denys Makogon
__________________________________________________________________________
OpenStack Development Mailing List (not for usage questions)
Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe<http://OpenStack-dev-request@lists.openstack.org?subject:unsubscribe>
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev

__________________________________________________________________________
OpenStack Development Mailing List (not for usage questions)
Unsubscribe: OpenStack-dev-request at lists.openstack.org?subject:unsubscribe<http://OpenStack-dev-request@lists.openstack.org?subject:unsubscribe>
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20160531/b874ba8e/attachment.html>