CODEWITHSUNDEEP
grafanaprometheus
kmoe
kmoe

Reputation: 2083

How do I write a Prometheus query that returns the value of a label?

I'm making a Grafana dashboard and want a panel that reports the latest version of our app. The version is reported as a label in the app_version_updated (say) metric like so:

app_version_updated{instance="eu99",version="1.5.0-abcdefg"}

I've tried a number of Prometheus queries to extract the version label as a string from the latest member of this time series, to no effect.

For example, the query

count(app_version_updated) by (version)

returns a {version="1.5.0-abcdefg"} element with a value of 1. When put in a Grafana dashboard in a single value panel, this doesn't display the version string but instead the count value (1).

How can I construct a Prometheus query that returns the version string?

Upvotes: 68

Views: 214285

Answers (9)

Carl Bergquist
Carl Bergquist

Reputation: 3942

We recently added support for displaying the series name as a value in the single stat panel (https://github.com/grafana/grafana/issues/4740). So you have to run our nightly build until we release version 4.0.

Just make sure the query returns one series and you can use the "name" value in the dropdown under Options -> big value. Then you can format the string using the legend formatter. Ex {{job}} would return "node" as a series name.

I hope this answers your question.

Upvotes: 17

Marcus Rickert
Marcus Rickert

Reputation: 4238

My answer tries to elaborate on Carl's answer. I assume that the GUI layout may have changed a little since 2016, so it took me while to find the "name" option.

Assuming you have a metric as follows:

# HELP db2_prometheus_adapter_info Information on the state of the DB2-Prometheus-Adapter
# TYPE db2_prometheus_adapter_info gauge
db2_prometheus_adapter_info{app_state="UP"} 1.0

and you would like to show the value of the label app_state.

Follow these steps:

  • Create a "SingleStat" visualization.
  • Go to the "Queries" tab:
    • Enter the name (here db2_prometheus_adapter_info) of the metric.
    • Enter the label name as the legend using the {{[LABEL]}} notation (here {{app_state}}).
    • Activate the "instant" option.

Settings in Queries Tab

  • Go to the "Visualization" tab:
    • Choose the value "Name" under "Value - Stat".

Setting in Visualization Tab

Note on the "Instant" setting: This setting switches from a range query to a simplified query only returning the most recent value of the metric (also see What does the "instant" checkbox in Grafana graphs based on prometheus do?). If not activated, the panel will show an error as soon as there is more than one distinct value for the label in the history of the metric. For a "normal" metric you would remedy this by choosing "current" in the "Value - Stat" option. But doing so here prevents your label value to be shown.

Upvotes: 37

Onluck
Onluck

Reputation: 81

You can use sum followed by the label you trying to get the value from.

For example:

sum(windows_cpu_info{instance="$hostname"}) by (l2_cache_size)

In this case, l2_cache_size is the label I wanted to get the returned value from.

Upvotes: 4

Junaid
Junaid

Reputation: 3995

With Stat visualization in Grafana 8+, you can set the legend to the intended label name and then change the Stat Styles -> Text Mode to Name enter image description here

Upvotes: 11

Marius
Marius

Reputation: 129

Another update on very latest kube-prometheus-stack using grafana 8.0.3. I still faced this issue, for me in a Bar gauge I still had this issue in scenarios where it only returned 1 value, but with 2+ values the Legend field works OK.

My solution:

Go to Edit Panel, find Display Name, type

${__field.labels.insertYourLegendValueHere}

Upvotes: 2

Niko Mol
Niko Mol

Reputation: 61

I wanted to get all the various values of a label from Prometheus to put into a variable in Grafana. I used this simple query to populate my varialbe Drop-Down list:

label_values(myLabelName)

This returned the expected "value01", "value02" etc

Upvotes: 2

Martin
Martin

Reputation: 506

While most of @marcus-rickert's answer is still valid in Grafana 7, there is some change. The 'Stat' 'Name' field seems to be gone, instead in the 'Field' panel, you can set the 'Display name' to the label you want to show.

enter image description here

Upvotes: 6

fargusto
fargusto

Reputation: 348

This worked for me.

label_values(my_metric{type= "xxx", another_label="xxx"},target_label)

Upvotes: 12

brian-brazil
brian-brazil

Reputation: 34172

Prometheus doesn't have any functions that return strings, what you're looking for is for a Grafana singlestat to be able to display a label value - which it unfortunately doesn't support yet.

https://github.com/grafana/grafana/issues/5094 tracks this.

Upvotes: 2

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