3 files changed, 57 insertions, 0 deletions
diff --git a/nixos/shared/postgresql.nix b/nixos/shared/postgresql.nix
index 6d9bb40..274895b 100644
--- a/nixos/shared/postgresql.nix
+++ b/nixos/shared/postgresql.nix
@@ -7,6 +7,7 @@
       authentication = pkgs.lib.mkOverride 10 ''
         #type database  DBuser  auth-method
         local sameuser  all     peer
+        local all       prometheus-sql-exporter peer
       '';
     };
   };
diff --git a/nixos/shared/prometheus-sql-exporter/default.nix b/nixos/shared/prometheus-sql-exporter/default.nix
new file mode 100644
index 0000000..81f1660
--- /dev/null
+++ b/nixos/shared/prometheus-sql-exporter/default.nix
@@ -0,0 +1,26 @@
+{
+  lib,
+  buildGoModule,
+  fetchFromGitHub,
+}:
+
+buildGoModule rec {
+  pname = "sql_exporter";
+  version = "0.17.1";
+
+  src = fetchFromGitHub {
+    owner = "burningalchemist";
+    repo = pname;
+    rev = version;
+    sha256 = "sha256-AEPFXPplHtny1P3gMvB1gbMj10bpu9PXc6ywliF+dCc=";
+  };
+
+  vendorHash = "sha256-KFWDqbdbXvgEtz1nlasWrvIckpzasUdzbb+AKfXmYf8=";
+
+  meta = with lib; {
+    description = "Database-agnostic SQL exporter for Prometheus";
+    mainProgram = "sql_exporter";
+    homepage = "https://github.com/burningalchemist/sql_exporter";
+    license = licenses.mit;
+  };
+}
diff --git a/nixos/shared/prometheus-sql-exporter/service.nix b/nixos/shared/prometheus-sql-exporter/service.nix
new file mode 100644
index 0000000..a887f91
--- /dev/null
+++ b/nixos/shared/prometheus-sql-exporter/service.nix
@@ -0,0 +1,30 @@
+# TODO: submit burningalchemist's sql_exporter to nixpkgs
+{ config, lib, pkgs, ... }:
+
+let
+  sqlExporter = pkgs.callPackage ./default.nix {};
+  cfg = config.services.prometheus-sql-exporter;
+  configFile =  builtins.toFile "config.yaml" (builtins.toJSON cfg.config);
+in
+{
+  options.services.prometheus-sql-exporter = {
+    enable = lib.mkEnableOption "sql-exporter";
+    port = lib.mkOption {
+      type = lib.types.int;
+    };
+    config = lib.mkOption {
+      type = (pkgs.formats.json {}).type;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.services.prometheus-sql-exporter = {
+      serviceConfig = {
+        ExecStart = "${sqlExporter}/bin/sql_exporter -config.file ${configFile} -web.listen-address :${toString cfg.port}";
+        DynamicUser = "true";
+        User = "prometheus-sql-exporter";
+      };
+      wantedBy = ["multi-user.target"];
+    };
+  };
+}