I've installed the grafana/k8s-monitoring Helm chart on my minikube cluster on my physical server (namespace rweather). I've also installed a single PostgreSQL database on that same node, namespace psql.

Following this guide from Grafana, I've used:

helm get values grafana-k8s-monitoring -n rweather > current-values.yaml

to export my current values.yaml, and insert the recommended snippet at the top (no top-level tag collision happens):

alloy:
  configs:
    integrations:
      enabled: true
      metrics:
        enabled: true
      logs:
        enabled: true

alloy-metrics:
  enabled: true
  extraConfig: |-
    prometheus.exporter.postgres "postgres" {
        data_source_names = ["postgresql://grafanareader:<redacted-pass>@postgres-rairquality-postgresql.psql.svc.cluster.local:5432/rairquality"]
    }

    prometheus.scrape "postgres" {
      targets      = prometheus.exporter.postgres.postgres.targets
      job_name     = "integrations/postgres_exporter"
      forward_to   = [prometheus.relabel.postgres.receiver]
    }

    prometheus.relabel "postgres" {
        rule {
            replacement = "postgres-rairquality-postgresql.psql.svc.cluster.local"
            target_label = "instance"
        }
        forward_to   = [prometheus.remote_write.grafana_cloud_metrics.receiver]
    }

podLogs:
  enabled: true
  extraDiscoveryRules: |-
    rule {
        source_labels = ["__meta_kubernetes_namespace", "__meta_kubernetes_pod_label_app_kubernetes_io_instance"]
        separator     = ":"
        regex         = "psql:postgres-rairquality"
        replacement   = "postgres"
        target_label  = "integration"
    }

    rule {
        source_labels = ["integration"]
        regex = "postgres"
        replacement = "postgres-rairquality-postgresql.psql.svc.cluster.local"
        target_label = "instance"
    }

    rule {
        source_labels = ["integration"]
        regex = "postgres"
        replacement = "integrations/postgres_exporter"
        target_label = "job"
    }

and use:

helm upgrade grafana-k8s-monitoring grafana/k8s-monitoring -n rweather -f current-values.yaml

to upgrade the chart.

I also force restart all pods, as well as double-check the values.yaml file after the upgrade command is finished.

However, on Grafana Cloud, the only notice I've gotten is: "No metrics were found for this integration." I've checked the pod logs (especially the alloy pod) and found no logs related to the connection to the DB. Overall, I don't know what went wrong since there're no further indicators anywhere; it's also likely that I misunderstood the guide.

Edit: I fot to mention this, but the problem is I can't get logs & metrics to work from the PostgreSQL integration - using it as a datasource works just fine.