Working with legends

In the previous sections, we spent some time learning how to manage the horizontal and vertical display of our graph data. Now, we’ll look at a key piece of graph display that is often overlooked: the legend. On many graphs, the legend seems like an afterthought, often floating in some non-specific whitespace where there’s a convenient lack of data.

Grafana is somewhat more restrained about the legend. It can live below the graph (or to its right) and can take on a list or a table format; that’s it. However, as we’ve seen, the label content of the graph can be set by the Alias field, and that field can be matched in field overrides. It’s that functionality that we can leverage when interacting with the legend interface.

Setting legend contents

Let’s start with another graph, again for temperature. Use the following query settings:

• FROM: temperature
• SELECT: field(value) | mean()
• GROUP BY: time($_interval...