niveum/systems/makanek/monitoring/default.nix

{
  lib,
  config,
  pkgs,
  ...
}: let
  lokiConfig = import ./loki.nix;
  blackboxConfig = import ./blackbox.nix;
  inherit (import <niveum/lib>) restic;
in {
  services.grafana = {
    enable = true;
    domain = "grafana.kmein.r";
    port = 9444;
    addr = "127.0.0.1";
  };

  services.nginx.virtualHosts.${config.services.grafana.domain} = {
    locations."/" = {
      proxyPass = "http://127.0.0.1:${toString config.services.grafana.port}";
      proxyWebsockets = true;
    };
  };

  services.prometheus.rules = let
    diskFreeThreshold = 10;
  in [
    (builtins.toJSON {
      groups = [
        {
          name = "niveum";
          rules = [
            {
              alert = "ServiceDown";
              expr = ''node_systemd_unit_state{state="failed"} == 1'';
              annotations = {
                summary = "{{$labels.name}} failed on {{$labels.job}}";
              };
            }
            {
              alert = "RootPartitionFull";
              for = "10m";
              expr = ''(node_filesystem_free_bytes{mountpoint="/"} * 100) / node_filesystem_size_bytes{mountpoint="/"} < ${toString diskFreeThreshold}'';
              annotations = {
                summary = ''{{ $labels.job }} running out of space: {{ $value | printf "%.2f" }}% < ${toString diskFreeThreshold}%'';
              };
            }
            {
              alert = "RootPartitionFullWeek";
              for = "1h";
              expr =
                ''node_filesystem_free_bytes{mountpoint="/"} ''
                + ''and predict_linear(node_filesystem_free_bytes{mountpoint="/"}[2d], 7*24*3600) <= 0'';
              annotations = {
                summary = "{{$labels.job}} running out of space in 7 days";
              };
            }
            {
              alert = "HighLoad";
              expr = ''node_load15 / on(job) count(node_cpu_seconds_total{mode="system"}) by (job) >= 1.0'';
              for = "10m";
              annotations = {
                summary = "{{$labels.job}} running on high load: {{$value}}";
              };
            }
            {
              alert = "HighRAM";
              expr = "node_memory_MemFree_bytes + node_memory_Buffers_bytes + node_memory_Cached_bytes < node_memory_MemTotal_bytes * 0.1";
              for = "1h";
              annotations.summary = "{{$labels.job}} using lots of RAM";
            }
            {
              alert = "UptimeMonster";
              expr = "time() - node_boot_time_seconds > 2592000";
              annotations.summary = "uptime monster {{$labels.job}} up for more than 30 days";
            }
            {
              alert = "HostDown";
              expr = ''up == 0'';
              for = "5m";
              annotations = {
                summary = "{{ $labels.job }} seeming down since 5 minutes";
              };
            }
            {
              alert = "Reboot";
              expr = "time() - node_boot_time_seconds < 300";
              annotations.summary = "{{$labels.job}} rebooted";
            }
            {
              alert = "ProbeFailed";
              expr = "probe_success == 0";
              for = "5m";
              annotations.summary = "HTTP probe failed for {{$labels.instance}}";
            }
            {
              alert = "SlowProbe";
              expr = "avg_over_time(probe_http_duration_seconds[1m]) > 1";
              for = "5m";
              annotations.summary = "HTTP probe slow for {{$labels.instance}}";
            }
            {
              alert = "HttpStatusCode";
              expr = "probe_http_status_code != 0 AND (probe_http_status_code <= 199 OR probe_http_status_code >= 400)";
              for = "5m";
              annotations.summary = "status code {{$value}} for {{$labels.instance}}";
            }
            {
              alert = "SslExpirySoon";
              expr = "probe_ssl_earliest_cert_expiry - time() < 86400 * 30";
              for = "5m";
              annotations.summary = "SSL certificate for {{$labels.instance}} expires in 30 days";
            }
            {
              alert = "SslExpiry";
              expr = "probe_ssl_earliest_cert_expiry - time()  <= 0";
              for = "5m";
              annotations.summary = "SSL certificate for {{$labels.instance}} has expired";
            }
          ];
        }
      ];
    })
  ];

  systemd.services.alertmanager-bot-telegram = {
    wantedBy = ["multi-user.target"];
    after = ["ip-up.target"];
    environment.TELEGRAM_ADMIN = "18980945";
    environment.TELEGRAM_TOKEN = lib.strings.fileContents <system-secrets/telegram/prometheus.token>;
    serviceConfig = {
      Restart = "on-failure";
      RestartSec = "15s";
      DynamicUser = true;
      StateDirectory = "alertbot";
      ExecStart = ''        ${pkgs.alertmanager-bot-telegram}/bin/alertmanager-bot \
                --alertmanager.url=http://localhost:9093 --log.level=info \
                --store=bolt --bolt.path=/var/lib/alertbot/bot.db \
                --listen.addr="0.0.0.0:16320" \
                --template.paths=${
          pkgs.writeText "template.tmpl" ''
            {{ define "telegram.default" }}
            {{range .Alerts -}}
            {{.Status}}: {{ index .Annotations "summary"}}
            {{end -}}
            {{end}}
          ''
        }'';
    };
  };

  services.prometheus.alertmanager = {
    enable = true;
    listenAddress = "localhost";
    configuration = {
      route = {
        group_wait = "30s";
        repeat_interval = "4h";
        receiver = "me";
      };
      receivers = [
        {
          name = "me";
          webhook_configs = [
            {
              url = "http://localhost:16320";
              send_resolved = true;
            }
          ];
        }
      ];
    };
  };

  services.prometheus.alertmanagers = [
    {
      scheme = "http";
      path_prefix = "/";
      static_configs = [{targets = ["localhost:9093"];}];
    }
  ];

  services.prometheus.scrapeConfigs = [
    {
      job_name = "makanek";
      static_configs = [
        {
          targets = [
            "127.0.0.1:${toString config.services.prometheus.exporters.node.port}"
          ];
        }
      ];
    }
    {
      scrape_interval = "5m";
      job_name = "blackbox";
      metrics_path = "/probe";
      params.module = ["http_2xx"];
      relabel_configs = [
        {
          source_labels = ["__address__"];
          target_label = "__param_target";
        }
        {
          source_labels = ["__param_target"];
          target_label = "instance";
        }
        {
          replacement = "127.0.0.1:${toString config.services.prometheus.exporters.blackbox.port}";
          target_label = "__address__";
        }
      ];
      static_configs = [
        {
          targets = [
            "alew.hu-berlin.de"
            "pad.kmein.de"
            "code.kmein.de"
            "radio.kmein.de"
            "tarot.kmein.de"
            "cloud.xn--kiern-0qa.de"
            "grafana.kmein.r"
            # "names.kmein.r"
            "rrm.r"
            "graph.r"
          ];
        }
      ];
    }
    {
      job_name = "zaatar";
      static_configs = [
        {
          targets = [
            "zaatar.r:${toString config.services.prometheus.exporters.node.port}"
            "zaatar.r:${toString restic.port}"
          ];
        }
      ];
    }
  ];

  services.prometheus.exporters.blackbox = {
    enable = true;
    configFile = (pkgs.formats.yaml {}).generate "blackbox.yaml" blackboxConfig;
  };

  networking.firewall.allowedTCPPorts = [
    lokiConfig.server.http_listen_port
  ];

  services.loki = {
    enable = true;
    configFile = (pkgs.formats.yaml {}).generate "loki.yaml" lokiConfig;
  };
}