argocd/alloy/values-development.yaml

alloy:
  alloy:
    configMap:
      content: |-
        loki.write "default" {
          endpoint {
            url = "http://loki-gateway.loki.svc.cluster.local/loki/api/v1/push"
            tenant_id = "luna"
          }
        }

        // local.file_match discovers files on the local filesystem using glob patterns and the doublestar library. It returns an array of file paths.
        local.file_match "node_logs" {
          path_targets = [{
              // Monitor syslog to scrape node-logs
              __path__  = "/var/log/messages",
              job       = "node/syslog",
              node_name = sys.env("HOSTNAME"),
              cluster   = "development",
          }]
        }

        // loki.source.file reads log entries from files and forwards them to other loki.* components.
        // You can specify multiple loki.source.file components by giving them different labels.
        loki.source.file "node_logs" {
          targets    = local.file_match.node_logs.targets
          forward_to = [loki.write.default.receiver]
        }

        // discovery.kubernetes allows you to find scrape targets from Kubernetes resources.
        // It watches cluster state and ensures targets are continually synced with what is currently running in your cluster.
        discovery.kubernetes "pod" {
          role = "pod"
        }

        // discovery.relabel rewrites the label set of the input targets by applying one or more relabeling rules.
        // If no rules are defined, then the input targets are exported as-is.
        discovery.relabel "pod_logs" {
          targets = discovery.kubernetes.pod.targets

          // Label creation - "namespace" field from "__meta_kubernetes_namespace"
          rule {
            source_labels = ["__meta_kubernetes_namespace"]
            action = "replace"
            target_label = "namespace"
          }

          // Label creation - "pod" field from "__meta_kubernetes_pod_name"
          rule {
            source_labels = ["__meta_kubernetes_pod_name"]
            action = "replace"
            target_label = "pod"
          }

          // Label creation - "container" field from "__meta_kubernetes_pod_container_name"
          rule {
            source_labels = ["__meta_kubernetes_pod_container_name"]
            action = "replace"
            target_label = "container"
          }

          // Label creation -  "app" field from "__meta_kubernetes_pod_label_app_kubernetes_io_name"
          rule {
            source_labels = ["__meta_kubernetes_pod_label_app_kubernetes_io_name"]
            action = "replace"
            target_label = "app"
          }

          // Label creation -  "job" field from "__meta_kubernetes_namespace" and "__meta_kubernetes_pod_container_name"
          // Concatenate values __meta_kubernetes_namespace/__meta_kubernetes_pod_container_name
          rule {
            source_labels = ["__meta_kubernetes_namespace", "__meta_kubernetes_pod_container_name"]
            action = "replace"
            target_label = "job"
            separator = "/"
            replacement = "$1"
          }

          // Label creation - "container" field from "__meta_kubernetes_pod_uid" and "__meta_kubernetes_pod_container_name"
          // Concatenate values __meta_kubernetes_pod_uid/__meta_kubernetes_pod_container_name.log
          rule {
            source_labels = ["__meta_kubernetes_pod_uid", "__meta_kubernetes_pod_container_name"]
            action = "replace"
            target_label = "__path__"
            separator = "/"
            replacement = "/var/log/pods/*$1/*.log"
          }

          // Label creation -  "container_runtime" field from "__meta_kubernetes_pod_container_id"
          rule {
            source_labels = ["__meta_kubernetes_pod_container_id"]
            action = "replace"
            target_label = "container_runtime"
            regex = "^(\\S+):\\/\\/.+$"
            replacement = "$1"
          }
        }

        // loki.source.kubernetes tails logs from Kubernetes containers using the Kubernetes API.
        loki.source.kubernetes "pod_logs" {
          targets    = discovery.relabel.pod_logs.output
          forward_to = [loki.process.pod_logs.receiver]
        }

        // loki.process receives log entries from other Loki components, applies one or more processing stages,
        // and forwards the results to the list of receivers in the component's arguments.
        loki.process "pod_logs" {
          stage.static_labels {
              values = {
                cluster = "development",
              }
          }

          forward_to = [loki.write.default.receiver]
        }

        // loki.source.kubernetes_events tails events from the Kubernetes API and converts them
        // into log lines to forward to other Loki components.
        loki.source.kubernetes_events "cluster_events" {
          job_name   = "integrations/kubernetes/eventhandler"
          log_format = "logfmt"
          forward_to = [
            loki.process.cluster_events.receiver,
          ]
        }

        // loki.process receives log entries from other loki components, applies one or more processing stages,
        // and forwards the results to the list of receivers in the component's arguments.
        loki.process "cluster_events" {
          forward_to = [loki.write.default.receiver]

          stage.static_labels {
            values = {
              cluster = "development",
            }
          }

          stage.labels {
            values = {
              kubernetes_cluster_events = "job",
            }
          }
        }