refactor: make Prometheus & Loki config reusable

4 files changed, 130 insertions, 95 deletions

diff --git a/nixos/hosts/tente/default.nix b/nixos/hosts/tente/default.nix
index e63b9bc..b9ac389 100644
--- a/nixos/hosts/tente/default.nix
+++ b/nixos/hosts/tente/default.nix
@@ -18,11 +18,13 @@ rec {
     <top/profiles/server>
     <top/shared/postgresql.nix>
     <top/shared/tailscale.nix>
+    <top/shared/monitoring.nix>
     ./web-personal.nix
     ./git.nix
     ./headscale.nix
     ./matrix.nix
-    ./monitoring.nix
+    ./exporters.nix
+    ./grafana.nix
     "${sources.my-lex-surf}/service.nix"
     "${sources.my-osm-proposals}/service.nix"
     "${sources.my-geopos-link}/service.nix"
@@ -115,17 +117,16 @@ rec {
       };
     };
 
-  monitoring.grafanaUiPort = 3000;
+  grafana.port = 3000;
+  grafana.matrixForwarderPort = 3002;
+  grafana.matrixServerUrl = "http://localhost:${toString matrix.port}";
   monitoring.alloyUiPort = 3001;
-  monitoring.grafanaMatrixForwarderPort = 3002;
   monitoring.lokiPort = 3030;
   monitoring.prometheusNodeExporterPort = 9002;
-  monitoring.prometheusSqlExporterPort = 9003;
+  exporters.sqlExporterPort = 9003;
   headscale.port = 8080;
   matrix.port = 8008;
 
-  monitoring.matrixServerUrl = "http://localhost:${toString matrix.port}";
-
   # Use the GRUB 2 boot loader.
   boot.loader.grub.enable = true;
   # boot.loader.grub.efiSupport = true;
diff --git a/nixos/hosts/tente/exporters.nix b/nixos/hosts/tente/exporters.nix
new file mode 100644
index 0000000..1ed53e5
--- /dev/null
+++ b/nixos/hosts/tente/exporters.nix
@@ -0,0 +1,55 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.exporters;
+in
+{
+  options.exporters = {
+    sqlExporterPort = lib.mkOption {
+      type = lib.types.int;
+    };
+  };
+
+  imports = [
+    <top/shared/prometheus-sql-exporter/service.nix>
+  ];
+
+  config = {
+    services.prometheus-sql-exporter = {
+      enable = true;
+      port = cfg.sqlExporterPort;
+      config = {
+        target = {
+          # This URL should be postgresql:///postgres?host=/run/postgresql
+          # but sql_exporter uses xo/dburl which isn't spec-compliant: https://github.com/xo/dburl/issues/46
+          data_source_name = "postgresql:/run/postgresql:/postgres";
+          collectors = ["db-sizes"];
+        };
+        collectors = [
+          {
+            collector_name = "db-sizes";
+            metrics = [
+              {
+                metric_name = "pg_db_size_bytes";
+                help = "disk space used by the database";
+                type = "gauge";
+                key_labels = ["database_name"];
+                values = ["size"];
+                query = "SELECT datname AS database_name, pg_database_size(datname) as size from pg_database";
+              }
+            ];
+          }
+        ];
+      };
+    };
+
+    monitoring.prometheusScrapeConfigs = [
+      {
+        job_name = "sql";
+        static_configs = [{
+          targets = [ "localhost:${toString cfg.sqlExporterPort}" ];
+        }];
+      }
+    ];
+  };
+}
diff --git a/nixos/hosts/tente/grafana.nix b/nixos/hosts/tente/grafana.nix
new file mode 100644
index 0000000..e6fb7af
--- /dev/null
+++ b/nixos/hosts/tente/grafana.nix
@@ -0,0 +1,63 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.grafana;
+in
+{
+  options.grafana = {
+    port = lib.mkOption {
+      type = lib.types.int;
+    };
+    matrixForwarderPort = lib.mkOption {
+      type = lib.types.int;
+    };
+    prometheusSqlExporterPort = lib.mkOption {
+      type = lib.types.int;
+    };
+    matrixServerUrl = lib.mkOption {
+      type = lib.types.str;
+    };
+  };
+
+  imports = [
+    <top/shared/prometheus-sql-exporter/service.nix>
+    <top/shared/grafana-matrix-forwarder/service.nix>
+  ];
+
+  config = {
+    age.secrets.grafana-matrix-forwarder-env.file = <top/secrets/grafana-matrix-forwarder-env.age>;
+
+    services.grafana = {
+      enable = true;
+      settings = {
+        server = {
+          http_addr = "0.0.0.0";
+          http_port = cfg.port;
+        };
+      };
+
+      provision = {
+        enable = true;
+        datasources.settings.datasources = [
+          {
+            name = "Prometheus Tente";
+            type = "prometheus";
+            url = "http://${config.services.prometheus.listenAddress}:${toString config.services.prometheus.port}";
+          }
+          {
+            name = "Loki Tente";
+            type = "loki";
+            access = "proxy";
+            url = "http://127.0.0.1:${toString config.services.loki.configuration.server.http_listen_port}";
+          }
+        ];
+      };
+    };
+    services.grafana-matrix-forwarder = {
+      enable = true;
+      port = cfg.matrixForwarderPort;
+      homeserver = cfg.matrixServerUrl;
+      environmentFile = config.age.secrets.grafana-matrix-forwarder-env.path;
+    };
+  };
+}
diff --git a/nixos/hosts/tente/monitoring.nix b/nixos/shared/monitoring.nix
index f6ed7cf..8711630 100644
--- a/nixos/hosts/tente/monitoring.nix
+++ b/nixos/shared/monitoring.nix
@@ -6,12 +6,6 @@ let
 in
 {
   options.monitoring = {
-    grafanaUiPort = lib.mkOption {
-      type = lib.types.int;
-    };
-    grafanaMatrixForwarderPort = lib.mkOption {
-      type = lib.types.int;
-    };
     lokiPort = lib.mkOption {
       type = lib.types.int;
     };
@@ -21,55 +15,12 @@ in
     prometheusNodeExporterPort = lib.mkOption {
       type = lib.types.int;
     };
-    prometheusSqlExporterPort = lib.mkOption {
-      type = lib.types.int;
-    };
-    matrixServerUrl = lib.mkOption {
-      type = lib.types.str;
+    prometheusScrapeConfigs = lib.mkOption {
+      type = lib.types.listOf lib.types.attrs;
+      default = [];
     };
   };
-
-  imports = [
-    <top/shared/prometheus-sql-exporter/service.nix>
-    <top/shared/grafana-matrix-forwarder/service.nix>
-  ];
-
   config = {
-    age.secrets.grafana-matrix-forwarder-env.file = <top/secrets/grafana-matrix-forwarder-env.age>;
-
-    services.grafana = {
-      enable = true;
-      settings = {
-        server = {
-          http_addr = "0.0.0.0";
-          http_port = cfg.grafanaUiPort;
-        };
-      };
-
-      provision = {
-        enable = true;
-        datasources.settings.datasources = [
-          {
-            name = "Prometheus";
-            type = "prometheus";
-            url = "http://${config.services.prometheus.listenAddress}:${toString config.services.prometheus.port}";
-          }
-          {
-            name = "Loki";
-            type = "loki";
-            access = "proxy";
-            url = "http://127.0.0.1:${toString cfg.lokiPort}";
-          }
-        ];
-      };
-    };
-    services.grafana-matrix-forwarder = {
-      enable = true;
-      port = cfg.grafanaMatrixForwarderPort;
-      homeserver = cfg.matrixServerUrl;
-      environmentFile = config.age.secrets.grafana-matrix-forwarder-env.path;
-    };
-
     services.prometheus = {
       enable = true;
 
@@ -82,13 +33,7 @@ in
             targets = [ "localhost:${toString cfg.prometheusNodeExporterPort}" ];
           }];
         }
-        {
-          job_name = "sql";
-          static_configs = [{
-            targets = [ "localhost:${toString cfg.prometheusSqlExporterPort}" ];
-          }];
-        }
-      ];
+      ] ++ cfg.prometheusScrapeConfigs;
 
       exporters.node = {
         enable = true;
@@ -97,34 +42,6 @@ in
       };
     };
 
-    services.prometheus-sql-exporter = {
-      enable = true;
-      port = cfg.prometheusSqlExporterPort;
-      config = {
-        target = {
-          # This URL should be postgresql:///postgres?host=/run/postgresql
-          # but sql_exporter uses xo/dburl which isn't spec-compliant: https://github.com/xo/dburl/issues/46
-          data_source_name = "postgresql:/run/postgresql:/postgres";
-          collectors = ["db-sizes"];
-        };
-        collectors = [
-          {
-            collector_name = "db-sizes";
-            metrics = [
-              {
-                metric_name = "pg_db_size_bytes";
-                help = "disk space used by the database";
-                type = "gauge";
-                key_labels = ["database_name"];
-                values = ["size"];
-                query = "SELECT datname AS database_name, pg_database_size(datname) as size from pg_database";
-              }
-            ];
-          }
-        ];
-      };
-    };
-
     services.loki = {
       enable = true;
       configuration = {
@@ -174,8 +91,7 @@ in
       serviceConfig = {
         SupplementaryGroups = [
           "systemd-journal"
-          "www-data"
-        ];
+        ] ++ lib.optional config.services.nginx.enable config.services.nginx.group;
       };
     };