Templating regex exclude not working

Grafana InfluxDB
,
1

I tried to exclude some hostname from the templating output.

Template query to get the hostname from InfluxDB,
SHOW TAG VALUES FROM system WITH KEY=host

As SHOW TAG VALUES doesn’t support time in WHERE clause, I tried to exclude some down hosts using template regex option.

Can you help me , how to exclude below hosts on templating regex option

ansys001.example.local
net001.example.local

Regex tried : /^(?!ansys.example.local$).*$/

2

You can use regex in the influxdb query as well to filter, or the regex option in grafana.

Not sure what the regex should look like.

3

Negative lookaheads are hard. Have you tried use the !~ operator (negative regex) in the the WHERE clause instead?

Something like: WHERE host !~ /^ansys*.example.local$/

4

I was just tackling this issue today.

My dashboard template variable is for a customer list from InfluxDB data source. The initial query looks like:
SHOW TAG VALUES FROM "series_name" WITH KEY = "customer"

Of course, I don’t want to look at any of my internal, test, or demo accounts, so I needed to use the regex to exclude those. I’m using the negative lookahead as daniellee mentioned, but since this is in the templating section and not the metrics, it’s a little different. My regex line has:
/^(?!abc|.*demo|.*test)/

This is working for me at this time. I hope it helps you out.

2 Likes
5

#Exclude all until remain what you want
/^(?!.postgres.|.pgsql-service.|kubelet.|haproxy-ingress.|.mssql-service.|kube-state-metrics.|billing-service.|default-http-backend.*|.jenkins.|.multideploy-service.|.nginx-service.|.openedge-service.|.project-db-service.|.project-db-test-service.|.project.|.source-service.|.mysql.|.rabbitmq.)/

#Exclude + Include feature (this is the best)
/(?=dev.|uat.|demo.|prod.|pre.|poc.)^(?!.postgres.|pgsql-service.*)/

#Include-only
/dev.|uat.|demo.|prod.|pre.|poc./

3 Likes
6

Does regex supports excluding value derived from other variable ? I want something like this for Prometheus,

Var 1 : Prometheus query returns Stack1, Stack2, Stack3
Var 2 : If I select Stack1, all services of Stack1

Something like chained variable but now in templating !
Or any other way to achieve this.

7

This worked for me. Thanks!

1 Like