Open Stack

Hi CM guys,

jd__ wanted to hold off the patch https://review.openstack.org/58747 because he thinks it's not generic enough and want to have a further discussion about the resource loader support. So I put it here my original thought and design about the patch as a start point.

The initial intension is to allow loading new resources(endpoints) without modifying the pipeline configuration file or restarting the central agent. If the admin sets the resource loader in the resources filed in the pipeline file, e.g.
    resources:
        - fileloader:///foo/bar
The central agent's PollingTask would use the corresponding resource loader to load new resources, every polling interval time before getting the samples from the pollsters for those endpoints. In the above configuration example, the file resource loader would read the resources definition from the file /foo/bar and pass those to the pollsters. The resource loader implementation can have its own internal cache, like the file resource loader, so it doesn't mean it has to open and read the whole file every polling time unless the corresponding file is updated.

If the resources defined in the pipeline doesn't match any resource file loader, it will be treated as directly passing to the pollsters. E.g.
    resources:
        - fileloader:///foo/bar
        - snmp://2.2.2.2
The endpoint 'snmp://2.2.2.2' will be passed to the pollsters along with the those read from the file /foo/bar.

Any comment?

p.s. Another patch https://review.openstack.org/#/c/58489/ for the same bp was approved before, but it failed in the gate test due to another previously merged patch. I've resolved that issue and would like to see reviews on this too. Thanks!

Best Regards,
-Lianhao Lu