Is your feature request related to a problem ?

I want to deploy an additional alertmanager instance using the alertmanager helmchart and want it scraped by prometheus. The helm chart does not contain a template for a servicemonitor. This forces me to either post-render patch the chart, rebuild-patch the chart with helmfile or add an umbrella chart.

Describe the solution you'd like.

I'd like a set of parameters in the values.yaml like for the kube-prometheus stack to enable and configure the servicemonitor (https://github.com/prometheus-community/helm-charts/blob/main/charts/kube-prometheus-stack/values.yaml#L568) and an according template.

Describe alternatives you've considered.

post-process patching with kustomize - requires an additional tool, additional step in the ci/cd pipeline, hard to parametrize

Additional context.

No response