In Grafana, I have a template variable which I want to pipe for running a prometheus query.
query{key='value1|value2|value3'} works for me.
Whereas, I have a template variable (Type: Query with Prometheus datasource and filtered with regex) called $t_var which can take values ['value1','value2','value3']
But, when I try the following query, I don't get any results:
query{key=~'${t_var:pipe}'}
Look at the pipe section in Grafana documentation: https://grafana.com/docs/reference/templating/
I have solved this problem without using any advanced formatting techniques such as pipe, json, csv, etc., as mentioned in this Grafana documentation.
Change required was very simple:
Instead of trying to concatenate list of template variables by pipe, I passed the whole template variable inside the query and also made 'Legend' as the template variable.
For example, my modified query is as follows:
query{key=~'[[t_var]]'
Legend format is {{t_var}}