Open Stack

On 10/01/2014 07:08 PM, Angus Lees wrote:
> On Wed, 1 Oct 2014 09:05:23 PM Fox, Kevin M wrote:
>> Has anyone figured out a way of having a floating ip like feature with
>> docker so that you can have rabbitmq, mysql, or ceph mon's at fixed ip's
>> and be able to migrate them around from physical host to physical host and
>> still have them at fixed locations that you can easily put in static config
>> files?
> This is part of the additional functionality kubernetes adds on top of docker.
>
> kubernetes uses a "proxy" on every host which knows about all the published
> "services".  The services share a port space (ie: every service has to have a
> unique port assigned), and the proxies know where to forward requests to find
> one of the backends for that service.
>
> docker communicates parameters via environment variables and has a few
> standard environment variables that are used for "links" to other containers.
> Kubernetes also uses these link env variables but points them at the proxies
> instead of directly to the other containers.  Since oslo.config can't look up
> environment variables directly (that's something I'd like to add), I have a
> simple shell one-liner that expands environment variables in the relevant
> config files before starting the openstack server.
>
> As a concrete example: I configure a keystone service in my kubernetes config
> and in my static config files I use values like:
>
>     identity_uri = http://$ENV[KEYSTONE_PORT_5000_TCP_ADDR]:
> $ENV[KEYSTONE_PORT_5000_TCP_PORT]/v2.0
>
> docker/kubernetes sets those env variables to refer to the proxy on the local
> host and the port number from my service config - this information is static
> for the lifetime of that docker instance.  The proxy will reroute the requests
> dynamically to wherever the actual instances are running right now.
>
> I hope that's enough detail - I encourage you to read the kubernetes docs
> since they have diagrams, etc that will make it much clearer than the above.
Really nice explanation.

+2!

Regards,
-steve

>   - Gus
>
>> Maybe iptables rules? Maybe adding another bridge? Maybe just disabling the
>> docker network stack all together and binding the service to a fixed,
>> static address on the host?
>>
>> Also, I ran across:
>> http://jperrin.github.io/centos/2014/09/25/centos-docker-and-systemd/ and
>> it does seem to work. I was able to get openssh-server and keystone to work
>> in the same container without needing to write custom start/stop scripts.
>> This kind of setup would make a nova compute container much, much easier.
>>
>> Thanks,
>> Kevin
>> ________________________________
>> From: Steven Dake [sdake at redhat.com]
>> Sent: Wednesday, October 01, 2014 8:04 AM
>> To: OpenStack Development Mailing List (not for usage questions)
>> Subject: Re: [openstack-dev] [kolla] Kolla Blueprints
>>
>> On 09/30/2014 09:55 AM, Chmouel Boudjnah wrote:
>>
>> On Tue, Sep 30, 2014 at 6:41 PM, Steven Dake
>> <sdake at redhat.com<mailto:sdake at redhat.com>> wrote:
>>
>> I've done a first round of prioritization.  I think key things we need
>> people to step up for are nova and rabbitmq containers.
>>
>> For the developers, please take a moment to pick a specific blueprint to
>> work on.  If your already working on something, this hsould help to prevent
>> duplicate work :)
>>
>>
>> As I understand in the current implementations[1]  the containers are
>> configured with a mix of shell scripts using crudini and other shell
>> command. Is it the way to configure the containers? and is a deployment
>> tool like Ansible (or others) is something that is planned to be used in
>> the future?
>>
>> Chmouel
>>
>> Chmouel,
>>
>> I am not really sure what the best solution to configure the containers.  It
>> is clear to me the current shell scripts are fragile in nature and do not
>> handle container restart properly.  The idea of using Puppet or Ansible as
>> a CM tool has been discussed with no resolution.  At the moment, I'm
>> satisified with a somewhat hacky solution if we can get the containers
>> operational.
>>
>> Regards,
>> -steve
>>
>>
>>
>>
>> [1] from https://github.com/jlabocki/superhappyfunshow/
>>
>>
>>
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