Open Stack

On 28/02/14 02:28, Qiming Teng wrote:
>
> The creation a stack is usually a time costly process, considering that
> there are cases where software packages need to be installed and
> configured.
>
> There are also cases where a stack consists of more than one VM instance
> and the dependency between instances.  The instances may have to be
> created one by one.
>
> Are Heat people considering adding some progress updates during the
> deployment?  For example, a simple log that can be printed by heatclient
> telling the user what progress has been made:
>
> Refreshing known resources types
> Receiving template <...>
> Validating template <...>
> Creating resource my_lb [AWS::EC2:LoadBalancer]
> Creating resource lb_instance1 [AWS::EC2::Instance]
> Creating resource latency_watcher [AWS::CloudWatch::Alarm]
> ....
> ...
>
>
> This would be useful for users to 'debug' their templates, especially
> when the template syntax is okay but its activities are not the intended
> one.

Yes, we need some sort of back-channel to feed information to the user - 
not only on progress but things like warnings. Right now we have to 
choose between failing a whole stack or not notifying the user at all 
when something is suspect.

The ReST model is unfortunately not conducive to this, as you generally 
don't want to keep the HTTP connection open and block until something is 
complete. One good idea floating around is to send the messages to a 
Marconi queue that the user can connect to.

It's all up for discussion in this blueprint:

https://blueprints.launchpad.net/heat/+spec/user-visible-logs

> Do we have to rely on heat-cfn-api to get these notifications?

No, you can also use the native api ;)

cheers,
Zane.