homeprod/kubernetes/infrastructure/observability/alloy-config.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: alloy-config
  namespace: observability
  labels:
    app.kubernetes.io/name: alloy
    app.kubernetes.io/component: log-collector
data:
  config.river: |
    // -----------------------------------------------------------------------------
    // Grafana Alloy — log collection only (metrics cluster+host collection is
    // handled by vmagent/node-exporter/cAdvisor elsewhere).
    // Forwards pod logs to the in-cluster Loki single-binary.
    // River config produced by `alloy convert -f promtail` from an equivalent
    // Promtail YAML (so component names and argument shapes are guaranteed
    // correct for Alloy v1.18).
    // -----------------------------------------------------------------------------

    discovery.kubernetes "kubernetes_pods" {
      role = "pod"

      selectors {
        role  = "pod"
        field = "spec.nodeName=" + coalesce(sys.env("HOSTNAME"), constants.hostname)
      }
    }

    loki.process "kubernetes_pods" {
      forward_to = [loki.write.default.receiver]

      // CRI-style log lines on the host: {"log":"...","stream":"stdout","time":"..."}
      stage.cri { }
    }

    discovery.relabel "kubernetes_pods" {
      targets = discovery.kubernetes.kubernetes_pods.targets

      rule {
        source_labels = ["__meta_kubernetes_namespace"]
        target_label  = "namespace"
      }
      rule {
        source_labels = ["__meta_kubernetes_pod_name"]
        target_label  = "pod"
      }
      rule {
        source_labels = ["__meta_kubernetes_pod_container_name"]
        target_label  = "container"
      }
    }

    loki.source.file "kubernetes_pods" {
      targets    = discovery.relabel.kubernetes_pods.output
      forward_to = [loki.process.kubernetes_pods.receiver]

      file_match {
        enabled = true
      }
      legacy_positions_file = "/tmp/positions.yaml"
    }

    loki.write "default" {
      endpoint {
        url = "http://loki.observability.svc.cluster.local:3100/loki/api/v1/push"
      }
      external_labels = {}
    }