nix/modules/monitor.nix

{ config, pkgs, device, ... }:

{
  services.cadvisor = {
    enable = true;
    port = 3022;
    extraOptions = ["--docker_only=false"];
  };
 
  services.prometheus = {
    enable = true;
    listenAddress = "127.0.0.1";
    port = 3020;
    webExternalUrl = "/prometheus/";
    checkConfig = true;
 
    exporters = {
      node = {
        enable = true;
        port = 3021;
        enabledCollectors = ["systemd"];
      };
    };
 
    scrapeConfigs = [
      {
        job_name = "node_exporter";
        static_configs = [
          {
            targets = [
              "127.0.0.1:${toString config.services.prometheus.exporters.node.port}"
            ];
          }
        ];
      }
      {
        job_name = "cadvisor";
        static_configs = [
          {
            targets = [
              "127.0.0.1:${toString config.services.cadvisor.port}"
            ];
          }
        ];
      }
    ];
  };

  services.loki = {
    enable = true;
    configuration = {
      server.http_listen_port = 3030;
      auth_enabled = false;
 
      common = {
        replication_factor = 1;
        path_prefix = "/tmp/loki";
        ring = {
          kvstore.store = "inmemory";
          instance_addr = "127.0.0.1";
        };
      };
 
      schema_config = {
        configs = [{
          from = "2020-05-15";
          store = "tsdb";
          object_store = "filesystem";
          schema = "v13";
          index = {
            prefix = "index_";
            period = "24h";
          };
        }];
      };
 
      storage_config.filesystem.directory = "/tmp/loki/chunks";
 
      analytics.reporting_enabled = false;
    };
  };

  users.groups.promtail = {};
  users.groups.nginx = {};
  users.users.promtail = {
    isSystemUser = true;
    group = "promtail";
    extraGroups = ["nginx"];
  };
 
  services.promtail = {
    enable = true;
    configuration = {
      server = {
        http_listen_port = 3031;
        grpc_listen_port = 0;
      };
      positions = {
        filename = "/tmp/positions.yaml";
      };
      clients = [
        {
          url = "http://127.0.0.1:${toString config.services.loki.configuration.server.http_listen_port}/loki/api/v1/push";
        }
      ];
      scrape_configs = [
        {
          job_name = "journal";
          journal = {
            max_age = "12h";
            labels = {
              job = "systemd-journal";
              host = "box";
              instance = "127.0.0.1";
            };
          };
          relabel_configs = [
            {
              source_labels = ["__journal__systemd_unit"];
              target_label = "unit";
            }
          ];
        }
        
        {
          job_name = "nginx";
          static_configs = [
            {
              targets = ["127.0.0.1"];
              labels = {
                job = "nginx";
                __path__ = "/var/log/nginx/*.log";
                host = "box";
                instance = "127.0.0.1";
              };
            }
          ];
        }
      ];
    };
  };

  environment.etc."grafana/dashboards" = {
    source = ./dashboards;
    user = "grafana";
    group = "grafana";
  };
 
  services.grafana = {
    enable = true;
 
    settings = {
      server = {
        http_addr = "127.0.0.1";
        http_port = 3010;
      };
      
      analytics = {
        reporting_enabled = false;
        feedback_links_enabled = false;
      };
    };
 
 
    provision = {
      enable = true;
      dashboards.settings.providers = [
        {
          options.path = "/etc/grafana/dashboards";
        }
      ];
      datasources.settings.datasources = [
        {
          name = "Prometheus";
          type = "prometheus";
          access = "proxy";
          url = "http://127.0.0.1:${toString config.services.prometheus.port}/prometheus";
        }
        {
          name = "Loki";
          type = "loki";
          access = "proxy";
          url = "http://127.0.0.1:${toString config.services.loki.configuration.server.http_listen_port}";
        }
      ];
    };
  };
}