Initial config framework

hosts/chapel/services/metrics/default.nix

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+{ config, pkgs, ... }:
+
+{
+  imports = [
+    ./prometheus.nix
+    ./grafana.nix
+    ./loki.nix
+    ./snmp-exporter.nix
+  ];
+}

hosts/chapel/services/metrics/grafana.nix

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+{ config, pkgs, ... }:
+
+let
+  cfg = config.services.grafana;
+in {
+  services.grafana = {
+    enable = true;
+    settings.server = {
+      domain = "grafana.feal.no";
+      http_port = 2342;
+      http_addr = "127.0.0.1";
+    };
+
+    provision = {
+      enable = true;
+      datasources.settings.datasources = [
+        {
+          name = "Prometheus";
+          type = "prometheus";
+          url = ("http://${config.services.prometheus.listenAddress}:${toString config.services.prometheus.port}");
+         isDefault = true;
+        }
+        {
+          name = "Loki";
+          type = "loki";
+          url = ("http://${config.services.loki.configuration.server.http_listen_address}:${toString config.services.loki.configuration.server.http_listen_port}");
+        }
+      ];
+      dashboards.settings.providers = [
+        {
+          name = "Node Exporter Full";
+          type = "file";
+          url = "https://grafana.com/api/dashboards/1860/revisions/29/download";
+          options.path = dashboards/node-exporter-full.json;
+        }
+        {
+          name = "Synology NAS Details";
+          type = "file";
+          url = "https://grafana.com/api/dashboards/14284/revisions/9/download";
+          options.path = dashboards/synology-nas-details.json;
+        }
+        {
+          name = "OpenWRT";
+          type = "file";
+          url = "https://grafana.com/api/dashboards/11147/revisions/1/download";
+          options.path = dashboards/openwrt.json;
+        }
+      ];
+    };
+  };
+
+  services.nginx.virtualHosts.${cfg.settings.server.domain} = {
+    locations = {
+      "/" = {
+        proxyPass = "http://127.0.0.1:${toString cfg.settings.server.http_port}";
+        proxyWebsockets = true;
+        extraConfig = ''
+          proxy_buffers 8 1024k;
+          proxy_buffer_size 1024k;
+        '';
+      };
+    };
+  };
+}

hosts/chapel/services/metrics/loki.nix

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+{ config, pkgs, ... }:
+
+let
+  cfg = config.services.loki;
+in {
+  services.loki = {
+    enable = true;
+    configuration = {
+      auth_enabled = false;
+      server = {
+        http_listen_port = 3100;
+        http_listen_address = "0.0.0.0";
+        grpc_listen_port = 9096;
+      };
+
+      ingester = {
+        wal = {
+          enabled = true;
+          dir = "/var/lib/loki/wal";
+        };
+        lifecycler = {
+          address = "127.0.0.1";
+          ring = {
+            kvstore = {
+              store = "inmemory";
+            };
+            replication_factor = 1;
+          };
+          final_sleep = "0s";
+        };
+        chunk_idle_period = "1h";
+      };
+
+      schema_config = {
+        configs = [
+          {
+            from = "2022-12-01";
+            store = "boltdb-shipper";
+            object_store = "filesystem";
+            schema = "v11";
+            index = {
+              prefix = "index_";
+              period = "24h";
+            };
+          }
+        ];
+      };
+
+      storage_config = {
+        boltdb_shipper = {
+          active_index_directory = "/var/lib/loki/boltdb-shipper-index";
+          cache_location = "/var/lib/loki/boltdb-shipper-cache";
+          shared_store = "filesystem";
+          cache_ttl = "24h";
+        };
+        filesystem = {
+          directory = "/var/lib/loki/chunks";
+        };
+      };
+
+      limits_config = {
+        enforce_metric_name = false;
+        reject_old_samples = true;
+        reject_old_samples_max_age = "72h";
+      };
+
+      compactor = {
+        working_directory = "/var/lib/loki/compactor";
+        shared_store = "filesystem";
+      };
+    };
+  };
+
+  networking.firewall.allowedTCPPorts = [ cfg.configuration.server.http_listen_port ];
+}

hosts/chapel/services/metrics/prometheus.nix

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+{ config, pkgs, ... }:
+
+let
+  cfg = config.services.prometheus;
+in {
+  services.prometheus = {
+    enable = true;
+    listenAddress = "127.0.0.1";
+    port = 9001;
+
+    scrapeConfigs = [
+      {
+        job_name = "node";
+        static_configs = [
+          {
+            targets = [
+              "chapel.home.feal.no:${toString cfg.exporters.node.port}"
+              "sulu.home.feal.no:9100"
+              "mccoy.home.feal.no:9100"
+              "borg.home.feal.no:9100"
+              "troi.home.feal.no:9100"
+              "dlink-feal.home.feal.no:9100"
+            ];
+          }
+        ];
+      }
+      {
+        job_name = "openwrt";
+        static_configs = [
+          { targets = ["dlink-feal.home.feal.no:9100"]; }
+        ];
+      }
+      {
+        job_name = "snmp";
+        static_configs = [{
+          targets = [
+            "feal-syn1.home.feal.no"
+            "feal-syn2.home.feal.no"
+          ];
+        }];
+        metrics_path = "/snmp";
+        params.module = ["synology"];
+        relabel_configs = [
+          {
+            source_labels = ["__address__"];
+            target_label = "__param_target";
+          }
+          {
+            source_labels = ["__param_target"];
+            target_label = "instance";
+          }
+          {
+            target_label = "__address__";
+            replacement = "127.0.0.1:9116";
+          }
+        ];
+      }
+    ];
+  };
+}

hosts/chapel/services/metrics/snmp-exporter.nix

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+{ config, pkgs, ... }:
+
+{
+  environment.systemPackages = [
+    pkgs.prometheus-snmp-exporter
+  ];
+
+  systemd.services.prometheus-snmp-exporter = {
+    enable = true;
+    description = "Gather data from SNMP devices and expose them as Prometheus metrics";
+    unitConfig = {
+      Type = "simple";
+    };
+    serviceConfig = {
+      ExecStart = "${pkgs.prometheus-snmp-exporter}/bin/snmp_exporter --config.file='/var/prometheus/snmp.yml'";
+      # TODO: Fix this conf file!
+    };
+    wantedBy = [ "multi-user.target" ];
+  };
+}