Add comma templating format

[stefan-improbable]

Grafana supports multi-selectable template variables for prometheus: http://docs.grafana.org/img/docs/v4/templated_dash.png. They can be used in query like up{server=~"$server"}, however count(up{server="abc"}) by ($groupby_vars) does not work. It is possible to hack around this, but it would be better if grafana supported this natively.

[mtanda]

I guess this issue is caused by all template variables are joined by "|".
https://github.com/grafana/grafana/blob/v5.0.0-beta1/public/app/plugins/datasource/prometheus/datasource.ts#L68

In by clause, we need to use "," character.

[stefan-improbable]

@mtanda yeah, that's correct. If there was an option to use , instead of | (we need both), it would solve my issue.

[torkelo]

this will be possible once we add a new interpolation syntax that will allow you to specify formatting when you use the variable:
#9911

example:

count(up{server=~"${server:regex}"}) by (${groupBy:comma})

[mtanda]

#11002 is merged.
But, unfortunately it contains extra { and }.
https://github.com/grafana/grafana/blob/v5.0.0/public/app/features/templating/template_srv.ts#L120

[torkelo]

Now we just need to add a comma format so ${host:comma} not sure what name is best comma or csv

[bergquist]

Closed by #11141