Document how to drive Ruler and AlertManager config

[bboreham]

Best I could find is https://cortexmetrics.io/docs/guides/alertmanager-configuration/, which doesn't cover what changed in #3888

There are several issues which boil down to "it isn't documented": #3401, #3395, #3148

[nschad]

I only found this just now (the hard way). If you check the Changelogs because you want to switch to alertmanager_storage, it says:

[FEATURE] Experimental Alertmanager Storage: Add a separate set of configuration options to configure the alertmanager storage backend under the -alertmanager-storage. flag prefix. All blocks storage bucket clients and the config service are currently supported. Clients using this implementation will only be enabled if the existing -alertmanager.storage flags are left unset. #3888

Which is correct, but it fails to mention that you also have you remove any mention of -<prefix>.configs.url which is the default in the cortex-helm-chart (used in alertmanager and ruler). Because of this check

func (cfg *LegacyConfig) IsDefaults() bool {
	return cfg.Type == configdb.Name && cfg.ConfigDB.ConfigsAPIURL.URL == nil
}

[bboreham]

Would you like to start a page in the documentation for this?

[nschad]

Would you like to start a page in the documentation for this?

Sure. Do you want me to add a new chapter here? https://cortexmetrics.io/docs/guides/alertmanager-configuration/

[pracucci]

Would you like to start a page in the documentation for this?

Sure. Do you want me to add a new chapter here? https://cortexmetrics.io/docs/guides/alertmanager-configuration/

I think that page can be restructured into a more general Alertmanager config doc 👍

[bboreham]

#4264 does not cover ruler config

[till]

@bboreham Thanks. My original ticket was about deprecating routes and how to keep track of that. :) For example, what is the new route replacing it.

[stale]

This issue has been automatically marked as stale because it has not had any activity in the past 60 days. It will be closed in 15 days if no further activity occurs. Thank you for your contributions.

[till]

Would someone exclude this? 😅