Can I apply a query/filter to all panel queries at dashboard level?

Question

I have a Prometheus server gathering metrics from several software installations. Each installation applies labels "Customer" & "System" to all metrics in the Prometheus relabel phase, and I have a Grafana dashboard which uses template variables $Customer, $System so my dashboard shows graphs for a single customer-system.

e.g. I can choose "Google/Test" or "Microsoft/Live" combinations.

This means all my queries are like my_counter_total{Customer='$Customer', System='$System'} which is rather tiring. Is there anyway to apply {Customer='$Customer', System='$System'} at dashboard level to all queries? The Grafana documentation hints it can be done but doesn't say how, and I cannot find a single example.

edit: As noted 'ad hoc queries' seem to be able to do this but the entire documentation is:

Ad hoc filters are one of the most complex and flexible variable options available. Instead of a regular list of variable options, this variable allows you to build a dashboard-wide ad hoc query. Filters you apply in this manner are applied to all panels on the dashboard.

So they tell me it's very complicated and leave me hanging :)

Answer 1

You can do that using an "Ad hoc filter" variable.

1. Go to Dashboard settings > Variables > New

2. Fill the options like the following example and click on Add

3. In this example, an Ad hoc filter variable called "Disk" will show in your dashboard:

4. You can choose how many label/value pair expressions you want to be used in this filter. In the following example, it was chosen "mountpoint=/home/cds/tool/bitbucket" so, magically, only the disk with this mountpoint was showed:

Note: The "mountpoint=/home/cds/tool/bitbucket" will automatically be used for all query expressions of all panes in the dashboard.

See more details in Grafana documentation here.