Grouping of alerts can not be disabled

[marcusboden]

Bug Description

Grouping of alerts can not be disabled.

To Reproduce

Put this into the config_file:

route:
  group_by:
  - ...

This should disable grouping entirely, according to the documentation.

When rolled out, the unit goes into blocked state and amtool reports:

root@alertmanager-0:/# amtool check-config /etc/alertmanager/alertmanager.yml 
Checking '/etc/alertmanager/alertmanager.yml'  FAILED: cannot have wildcard group_by (`...`) and other other labels at the same time

The config itself has:

route:
  group_by:
  - juju_model_uuid
  - juju_application
  - '...'
  - juju_model

Environment

I tried this locally, as well as on customer clouds running latest/stable.

Relevant log output

Checking '/etc/alertmanager/alertmanager.yml'  FAILED: cannot have wildcard group_by (`...`) and other other labels at the same time

Additional context

No response

[simskij]

Before we go into implementation discussions: What is it that you're trying to achieve? What are the limitations you're seeing with the current grouping strategy?

[marcusboden]

I want the grouping to happen in Pagerduty. Most of our alerts are not grouped anyway and our alertmanager config is set up in a way that is best for ungrouped alerts. So now, when there are alerts that only differ is a label we did not anticipate, those are grouped together and our alerts become hard to read.

Since we didn't have any grouping in the alerting before, we'd like to turn it off.