rawQuery passed to backend part with $template_variable

[Slach]

maybe it happens cause grafana start before clickhouse and can't parse template variable values when clickhouse shutdown

[Slach]

Unfortunately, grafana generally currently doesn't support template variables for alerting queries.
Also, grafana UI doesn't pass template variables values to a backend, after you change it on frontend UI.

So, the clickhouse grafana plugin can use template variables values, because we have "Generated SQL" which pass to backend "as is"
To ensure template variables values will properly pass to a backend part of the plugin.
Please choose the required template variables values for your alerts in UI dropdown,
ensure values properly rendered in "Generated SQL" (maybe need change SQL query in query editor)
and save a whole dashboard to the Grafana server

WARNING: Test alert button doesn't save a current state of alert rules to a backend part of the plugin.

If "Generated SQL" passed properly into backend part of plugin. You will see something like this

You also can try to troubleshoot alerts in clickhouse grafana plugin when enable level=debug in log section grafana.ini or via GF_LOG_LEVEL=debug environment variable.