logging {
  level = "warn"
}



// ============================================
// Discovery: Kubernetes - endpoints
// used by:
// - loki kubernetes kube state metrics
// ============================================
discovery.kubernetes "kube_endpoints" {
  role = "endpoints"
}


// ============================================
// Metrics: Prometheus Remote Write 
// ============================================
prometheus.remote_write "prometheus_srv" {
  endpoint {
    url = sys.env("PROMETHEUS_URL")
  }
  external_labels = {
    cluster = sys.env("CLUSTER_NAME"),
    zone    = sys.env("ZONE"),
  }
}


// ============================================
// CoreDNS discovery (ENDPOINTS)
// ============================================

discovery.relabel "coredns" {
  targets = discovery.kubernetes.kube_endpoints.targets

  rule {
    source_labels = ["__meta_kubernetes_service_name"]
    regex         = "(kube-dns|coredns)"
    action        = "keep"
  }

  rule {
    regex  = ".*_uid$|.*_id$|^annotation_.*|^label_.*|^endpoint_.*|^pod_ip$"
    action = "drop"
  }

  rule {
    regex  = "coredns_cache_.*|coredns_forward_.*"
    action = "drop"
  }

  rule {
    source_labels = ["__meta_kubernetes_endpoint_node_name"]
    target_label  = "node"
  }

  rule {
    action        = "replace"
    target_label  = "__address__"
    replacement   = "$__meta_kubernetes_endpoint_address:9153"
  }

  rule {
    target_label = "cluster"
    replacement  = sys.env("CLUSTER_NAME")
  }

  rule {
    target_label = "zone"
    replacement  = sys.env("ZONE")
  }

}

// ============================================
// CoreDNS scrape
// ============================================
prometheus.scrape "coredns" {
  job_name = "integrations/kubernetes/coredns"
  targets  = discovery.relabel.coredns.output

  scheme = "http"
  metrics_path = "/metrics"

  forward_to = [prometheus.remote_write.prometheus_srv.receiver]
}