Enable "Start Relative" on Check Charts widget of ZMON dashboards

A user has requested the possibility to use "start_relative" config on check charts for the dashboard widgets, as it is only available on kairos charts. This configuration allows users to set the time span of the chart (X axis span, i.e. 10min, 30min, etc).

Currently Chart widgets display any data that comes back on the response. Kairos charts allow the user to specify a start_relative config which is passed to the backend. Check charts on the other hand do not support this config and will respond with any data available for a given check.

"start_relative": { "value": "30", "unit": "minutes" },

@elauria Can you confirm, does the user mean..?

1. They want to specify the start date for a Check Chart (with 'now' as a given end time) or
2. They want to specify specific start and end times when viewing Check Charts or
3. They want to see the Check Chart for X minutes ago.

@laceyallyn so the idea is to have the same option that kairosdb offers. From kairosdb docs, its describe like this:

start_relative The relative start time is the current date and time minus the specified value and unit. Possible unit values are “milliseconds”, “seconds”, “minutes”, “hours”, “days”, “weeks”, “months”, and “years”. For example, if the start time is 5 minutes, the query will return all matching data points for the last 5 minutes.

So the answer would be 1 🥇

This should be a UI and a backend change

Needs redesign of the Check-->Alert workflow