resource "kubernetes_config_map" "alertmanager" {
  metadata {
    name      = "alertmanager-conf"
    namespace = kubernetes_namespace.prometheus.metadata[0].name
    labels = {
      name = "alertmanager-conf"
    }
  }

  data = {
    "alertmanager.yml" = local.alertmanager_config
  }
}

resource "kubernetes_deployment" "alertmanager" {
  metadata {
    name      = "alertmanager"
    namespace = kubernetes_namespace.prometheus.metadata[0].name
    labels = {
      app = "alertmanager"
    }
  }

  spec {
    replicas = 1

    selector {
      match_labels = {
        app = "alertmanager"
      }
    }

    template {
      metadata {
        labels = {
          app = "alertmanager"
        }
        annotations = {
          "checksum/config" = local.alertmanager_config_checksum
        }
      }

      spec {
        container {
          name  = "alertmanager"
          image = "prom/alertmanager:${local.app_version}"

          args = [
            "--config.file=/etc/alertmanager/alertmanager.yml",
            "--storage.path=/alertmanager"
          ]

          port {
            name           = "http"
            container_port = 9093
          }

          volume_mount {
            name       = "alertmanager-config"
            mount_path = "/etc/alertmanager"
          }

          volume_mount {
            name       = "alertmanager-storage"
            mount_path = "/alertmanager"
          }

          security_context {
            run_as_user                = 1000
            run_as_group               = 1000
            run_as_non_root            = true
            allow_privilege_escalation = false
          }
        }

        volume {
          name = "alertmanager-config"
          config_map {
            name = kubernetes_config_map.alertmanager.metadata[0].name
          }
        }

        volume {
          name = "alertmanager-storage"
          host_path {
            path = local.alertmanager_folder
            type = "DirectoryOrCreate"
          }
        }
      }
    }
  }
}

resource "kubernetes_service" "alertmanager" {
  metadata {
    name      = "alertmanager"
    namespace = kubernetes_namespace.prometheus.metadata[0].name
    labels = {
      app = "alertmanager"
    }
  }

  spec {
    selector = {
      app = "alertmanager"
    }

    type = "ClusterIP"

    port {
      name        = "web"
      port        = 9093
      protocol    = "TCP"
      target_port = "http"
    }
  }
}