Backend: initial alerting query

[alexanderzobnin]

In order to make alerting working, querying data source target should be reimplemented on the backend side. This makes sense only for time series data, so first part may be implementing queryNumericData method from the frontend.
For this purpose, a new query type should be created and used as a default. Main problem is implementing query parser which should fetch groups, hosts, apps, items and then parse regex filters to recognize items which should be queried.
https://github.com/alexanderzobnin/grafana-zabbix/blob/6e80b491205168a2744970bfd0403a76447e580b/pkg/datasource.go#L29-L34

[vignesh-reddy]

@alexanderzobnin I will be able to help with this issue and if there is any sample query can you point me to that. It will help me understand and test the implemented method.

[alexanderzobnin]

@vignesh-reddy that's quite a lot of work. Try to take a look at queryNumericData method on the frontend:
https://github.com/alexanderzobnin/grafana-zabbix/blob/ca50d0db98638f079256417689a15fc3672d1f84/src/datasource-zabbix/datasource.js#L172
In order to get data from zabbix, data source should parse query first by fetching groups, hosts, apps and items.