[Kimchi-devel] [RFC] Plugin management - disable/enable WoK plug-ins

[Aline Manera]

Hi Daniel,

On 01/10/2017 10:24 AM, Daniel Henrique Barboza wrote:
> Hi there,
>
> I am working in a way to enable/disable WoK plug-ins using an API. 
> This is
> what we already have regarding plugin management:
>
> - each plug-in has a configuration file, for example ginger.conf:
>
> [wok]
> # Enable Ginger plugin on Wok server (values: True|False)
> enable = True
>
> (...)
>
>
> - an API that returns all enable plug-ins:
>
> $  curl -k -u danielhb -H "Content-Type: application/json" -H "Accept: 
> application/json" -X GET 'https://localhost:8001/plugins'
> Enter host password for user 'danielhb':
> [
>   "gingerbase",
>   "kimchi",
>   "ginger"
> ]
>
> The API retrieves the contents of each plug-in config file and return the
> plug-in name if enable = True.
>
>
> This is my proposal to implement this new feature without messing around
> too much:
>
> - the /plugins API will now returns all plug-ins, regardless of the 
> plug-in being
> loaded or not. In the previous example the returned value would be:
>
> [{ "name: "gingerbase", "enabled": True} ,
>  { "name: "ginger", "enabled": True},
>  { "name: "kimchi", "enabled": True} ]
>

If you are saying to keep /plugins as a SimpleColletion, I do not agree 
on that.

The /plugins API should be changed to be a Collection of Resources.
So GET /plugins will return all the plugins (the same way you did above) 
and GET /plugins/*name* will return the information about a single plugin.

>
> Changes in the existing API calls will be made considering this new 
> format.
>
> - A new PUT method to change the 'enabled' attribute of the plug-ins. 
> Changing
> the attribute will write the new value in the plug-in config file, 
> allowing WoK
> to enable/disable the plug-in in the next reboot.
>

The action enable/disable should be a POST method on a Resource elemente 
instead of PUT.

POST /plugins/*name*/enable
POST /plugins/*name*/disable

> - To make the changes effective we need to reboot WoK after 
> enabling/disabling
> a plug-in. This can be done by either rebooting WoK in the same PUT 
> operation I
> mentioned above or by a new 'reboot' API in WoK. I am more fond of a 
> new API
> but I can live with this 'super PUT' API too.
>

I am OK to add a new API to reload the server configuration.

>
> Note that at this moment we will not supporting load/unload of 
> plug-ins without
> rebooting WoK. This has proven to be challenging considering our current
> plug-in loading schema in cherrypy.
>
>

OK.

You should consider the plugins dependencies as well.

Kimchi depends on Ginger Base UI to build the Peers feature UI. So 
disabling Ginger Base implies in disabling Kimchi.
What about Ginger? And Ginger s390x?

> Thoughts?
>
>
> Daniel
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