ildkule: set up postgres metrics exporter

hosts/ildkule/services/metrics/prometheus/default.nix

@@ -2,6 +2,7 @@
   imports = [
     ./node.nix
     ./matrix-synapse.nix
+    ./postgres.nix
   ];
   
   services.prometheus = {

hosts/ildkule/services/metrics/prometheus/postgres.nix

@@ -0,0 +1,23 @@
+{ config, values, ... }: let
+  cfg = config.services.prometheus;
+in {
+  sops.secrets."keys/postgres/postgres_exporter_env" = {
+    
+  };
+
+  services.prometheus = {
+    scrapeConfigs = [{
+      job_name = "postgres";
+      scrape_interval = "15s";
+      static_configs = [{
+        targets = [ "localhost:${toString cfg.exporters.postgres.port}" ];
+      }];
+    }];
+
+    exporters.postgres = {
+      enable = true;
+      extraFlags = [ "--auto-discover-databases" ];
+      environmentFile = config.sops.secrets."keys/postgres/postgres_exporter_env".path;
+    };
+  };
+}