apiVersion: v1
kind: ConfigMap
metadata:
  name: alloy-config
  namespace: default
data:
  config.alloy: |
    // 发现集群内所有 Pod
    discovery.kubernetes "pods" {
      role = "pod"
    }

    // 重写元数据标签,并只保留带 app label 的 Pod
    discovery.relabel "pods" {
      targets = discovery.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"
      }
      rule {
        source_labels = ["__meta_kubernetes_pod_label_app"]
        target_label  = "app"
      }
      // 只采集有 app label 的 Pod
      rule {
        source_labels = ["__meta_kubernetes_pod_label_app"]
        action        = "keep"
        regex         = ".+"
      }
    }

    // 通过 Kubernetes API 抓取容器日志(无需挂载宿主机日志目录)
    loki.source.kubernetes "pods" {
      targets    = discovery.relabel.pods.output
      forward_to = [loki.process.parse.receiver]
    }

    // 解析 zap 输出的 JSON 日志,并将关键字段提升为 Loki Label
    loki.process "parse" {
      forward_to = [loki.write.default.receiver]

      // 解析结构化字段
      stage.json {
        expressions = {
          level     = "level",
          traceID   = "traceID",
          spanID    = "spanID",
          caller    = "caller",
          pod       = "pod",
          namespace = "namespace",
          node      = "node",
        }
      }

      // 提升为 Label,支持在 Grafana 中按实例/Trace 过滤
      stage.labels {
        values = {
          level     = "",
          traceID   = "",
          pod       = "",
          namespace = "",
          node      = "",
        }
      }
    }

    // 推送到 Loki
    loki.write "default" {
      endpoint {
        url = "http://loki-service:3100/loki/api/v1/push"
      }
    }