Tags and grafana multi-value variables

[msaf1980]

For example, query like
seriesByTag(.., 'instance=${Instance}', ..)

If selected instances 1 and 10 (grafana with multi-value variable), grafana expand this to

seriesByTag(.., 'instance={1,10}', ..)

graphite-clickhouse produce wrong query like
SELECT Path FROM graphite_tags2 WHERE ((((((.. AND (arrayExists((x) -> x='instance={1,10}', Tags))) ..

Also match pattern not have ^ at the begging and $ at the end. So we have more than expected metrics in results.