Feature request: A command line mode be made to validate alertmanager configuration

[dannystaple]

Is your feature request related to a problem? Please describe.

Our mimir configuration is done through a CI system, and is deployed out to multiple instances in multiple environments. We have validations for many items before a new change can go into that.

Performing alertmanager load clearly validates before the configuration is uploaded to a server, however it can break if an incorrect config has been merged into the main branch. We do not have a way to validate this config before this is merged.

Describe the solution you'd like

It would useful for validation of changes into our deployable main, to have something like mimirtool alertmanager verify <config> that would perform the validation, but without requiring to upload to a server afterwards.

Describe alternatives you've considered

Building a bash script around alertmanager load that will filter out an error due to ERRO[0000] error during request to Grafana Mimir API and give it dummy URI's and credentials.

Additional context

N/A

[dannystaple]

Potentially a flag for load config, that stopped around

mimir/pkg/mimirtool/commands/alerts.go

Line 126 in 5356edd

}

might do this.

[dannystaple]

I have created a PR for this - however, I was not able to find any tests around the mimirtool alertmanager load command handler.