Variables in Grafana with examples

Grafana variables

• Variables in Grafana can be used to use common values in dashboard queries, titles etc.
• Variables can be used to create input elements like select boxes, text inputs that can change the dashboard based on user input
• A variable can also be used in another variable (chained variables). This can be used to create hierarchical select boxes for user inputs

Manage variables in a dashboard

• As shown below, go to the dashboard settings page and go to the variables tab

Variable types

Query variable

• The variable value select list options will be fetched from a datasource using a query

Custom variable

• The variable value select list options will be defined manually

Text box variable

• The variable value can be defined by the user in a textbox

Using variable in the query of a visualization

• Variable value can be used in a query of the visualization as shown in the above image
• In the above example, using $state_name in the query will use value of the state_name variable
• The above example uses a variable in an infinity datasource query. In a similar way, variables can be used in any datasource queries (like PostgreSQL, JSON, SQL Server etc.)

Using variable in a visualization title

• In the above example, value of the variable state_name is used in a visualization title using $state_name

Nested Variables and Hierarchical Select boxes

• A variable can be used in the query of another variable
• Hence the drop-down values of one variable can be dependent on the value of another variable. This can help in creating hierarchical drop-downs as shown in the above example.

Video

Video on this post can be seen here

References

• Official documentation - https://grafana.com/docs/grafana/latest/dashboards/variables/
• Sample dataset used - https://www.kaggle.com/datasets/shubhendra7/indian-cities-analysis?resource=download