ec2 provider issue with name resolution on multi_host mode

[Pierre Amadio]

When using multi_host mode on a openstack deployement, each node running nova-network run a an instance of dnsmasq to give ip address and name resolution to vm running on this host.

The several dnsmasq process do not share the information they have about the running vm. As a result, a virtual machine will only be able to resolve name of other vm running on the same compute node it s currently hosted on.

This is causing some problems when deploying charms with the ec2 provider.

The most common problem i hit is when attempting to add a relation between some charm and a mysql charm.

There also seems to be possible reference to the zookeeper node hostname (instead of its ip) wich would result in the same problem.

By example:

juju bootstrap
juju deploy mysql
juju deploy wordpress
juju add-relation wordpress mysql
juju expose wordpress

after installation, there are several references to host names instead of host ips:

1) In /etc/init/juju-wordpress-0.conf

env JUJU_ZOOKEEPER="server-8f4f305f-0214-4bbf-8846-57925ca2c56f:2181"

2) In /var/www/wp-info.php:

define('DB_HOST', 'server-8eebd3d8-1de7-4984-889e-8a6f4ea48fc8.canonistack');

Here, the charm having a relation with the mysql charm is given the mysql host name in the relation-get , instead of its ip.

[Kapil Thangavelu (hazmat)]

highly recommended to use the 'openstack' provider against openstack
environments.

On Tue, Jan 22, 2013 at 9:36 AM, Pierre Amadio
<email address hidden>wrote:

> Public bug reported:
>
> When using multi_host mode on a openstack deployement, each node running
> nova-network run a an instance of dnsmasq to give ip address and name
> resolution to vm running on this host.
>
> The several dnsmasq process do not share the information they have about
> the running vm. As a result, a virtual machine will only be able to
> resolve name of other vm running on the same compute node it s currently
> hosted on.
>
> This is causing some problems when deploying charms with the ec2
> provider.
>
> The most common problem i hit is when attempting to add a relation
> between some charm and a mysql charm.
>
> There also seems to be possible reference to the zookeeper node
> hostname (instead of its ip) wich would result in the same problem.
>
> By example:
>
> juju bootstrap
> juju deploy mysql
> juju deploy wordpress
> juju add-relation wordpress mysql
> juju expose wordpress
>
> after installation, there are several references to host names instead
> of host ips:
>
> 1) In /etc/init/juju-wordpress-0.conf
>
> env JUJU_ZOOKEEPER="server-8f4f305f-0214-4bbf-8846-57925ca2c56f:2181"
>
> 2) In /var/www/wp-info.php:
>
> define('DB_HOST', 'server-8eebd3d8-1de7-4984-889e-
> 8a6f4ea48fc8.canonistack');
>
> Here, the charm having a relation with the mysql charm is given the
> mysql host name in the relation-get , instead of its ip.
>
> ** Affects: juju
> Importance: Undecided
> Status: New
>
> --
> You received this bug notification because you are subscribed to juju.
> https://bugs.launchpad.net/bugs/1103036
>
> Title:
> ec2 provider issue with name resolution on multi_host mode
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/juju/+bug/1103036/+subscriptions
>

[Matt Rae (mattrae)]

Hi Kapil, will this issue be investigated for the juju ec2 provider on openstack? There are other issues with the openstack provider that are also being investigated.

[Matt Rae (mattrae)]

I've encountered this problem as well using juju with the openstack provider and can work with anybody to debug, provide logs, etc.

[Matt Rae (mattrae)]

Sorry in the previous comment i meant to say ec2 provider rather than openstack.

"I've encountered this problem as well using juju with the ec2 provider and can work with anybody to debug, provide logs, etc."

[Kapil Thangavelu (hazmat)]

its not really supported at this point to use the ec2 provider on openstack, the native openstack provider uses ip addresses instead of dns names which typically resolves this connectivity issue (assuming multi host properly bridged).

[Kapil Thangavelu (hazmat)]

if there are openstack provider issues, i'd be happy to have a look