Merge pull request #65751 from mayflower/pkgs/prometheus-postgres-exporter

prometheus-postgres-exporter: init at 0.5.1

nixos/modules/services/monitoring/prometheus/exporters.nix

@@ -33,6 +33,7 @@ let
     "nginx"
     "node"
     "postfix"
+    "postgres"
     "snmp"
     "surfboard"
     "tor"

nixos/modules/services/monitoring/prometheus/exporters/postgres.nix

@@ -0,0 +1,46 @@
+{ config, lib, pkgs, options }:
+
+with lib;
+
+let
+  cfg = config.services.prometheus.exporters.postgres;
+in
+{
+  port = 9187;
+  extraOpts = {
+    telemetryPath = mkOption {
+      type = types.str;
+      default = "/metrics";
+      description = ''
+        Path under which to expose metrics.
+      '';
+    };
+    dataSourceName = mkOption {
+      type = types.str;
+      default = "user=postgres database=postgres host=/run/postgresql sslmode=disable";
+      example = "postgresql://username:password@localhost:5432/postgres?sslmode=disable";
+      description = ''
+        Accepts PostgreSQL URI form and key=value form arguments.
+      '';
+    };
+    runAsLocalSuperUser = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Whether to run the exporter as the local 'postgres' super user.
+      '';
+    };
+  };
+  serviceOpts = {
+    environment.DATA_SOURCE_NAME = cfg.dataSourceName;
+    serviceConfig = {
+      User = mkIf cfg.runAsLocalSuperUser (mkForce "postgres");
+      ExecStart = ''
+        ${pkgs.prometheus-postgres-exporter}/bin/postgres_exporter \
+          --web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          --web.telemetry-path ${cfg.telemetryPath} \
+          ${concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}

nixos/tests/prometheus-exporters.nix

@@ -274,6 +274,30 @@ let
       '';
     };
 
+    postgres = {
+      exporterConfig = {
+        enable = true;
+        runAsLocalSuperUser = true;
+      };
+      metricProvider = {
+        services.postgresql.enable = true;
+      };
+      exporterTest = ''
+        waitForUnit("prometheus-postgres-exporter.service");
+        waitForOpenPort(9187);
+        waitForUnit("postgresql.service");
+        succeed("curl -sSf http://localhost:9187/metrics | grep -q 'pg_exporter_last_scrape_error 0'");
+        succeed("curl -sSf http://localhost:9187/metrics | grep -q 'pg_up 1'");
+        systemctl("stop postgresql.service");
+        succeed("curl -sSf http://localhost:9187/metrics | grep -qv 'pg_exporter_last_scrape_error 0'");
+        succeed("curl -sSf http://localhost:9187/metrics | grep -q 'pg_up 0'");
+        systemctl("start postgresql.service");
+        waitForUnit("postgresql.service");
+        succeed("curl -sSf http://localhost:9187/metrics | grep -q 'pg_exporter_last_scrape_error 0'");
+        succeed("curl -sSf http://localhost:9187/metrics | grep -q 'pg_up 1'");
+      '';
+    };
+
     snmp = {
       exporterConfig = {
         enable = true;

pkgs/servers/monitoring/prometheus/postgres-exporter.nix

@@ -0,0 +1,24 @@
+{ stdenv, buildGoPackage, fetchFromGitHub }:
+
+with stdenv.lib;
+
+buildGoPackage rec {
+  name = "postgres_exporter-${version}";
+  version = "0.5.1";
+
+  goPackagePath = "github.com/wrouesnel/postgres_exporter";
+
+  src = fetchFromGitHub {
+    owner = "wrouesnel";
+    repo = "postgres_exporter";
+    rev = "v${version}";
+    sha256 = "1awcqhiak56nrsaa49lkw6mcbrlm86ls14sp9v69h3a0brc1q7bn";
+  };
+
+  meta = {
+    inherit (src.meta) homepage;
+    description = "A Prometheus exporter for PostgreSQL";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ fpletz ];
+  };
+}

pkgs/top-level/all-packages.nix

@@ -14806,6 +14806,7 @@ in
   prometheus-node-exporter = callPackage ../servers/monitoring/prometheus/node-exporter.nix { };
   prometheus-openvpn-exporter = callPackage ../servers/monitoring/prometheus/openvpn-exporter.nix { };
   prometheus-postfix-exporter = callPackage ../servers/monitoring/prometheus/postfix-exporter.nix { };
+  prometheus-postgres-exporter = callPackage ../servers/monitoring/prometheus/postgres-exporter.nix { };
   prometheus-pushgateway = callPackage ../servers/monitoring/prometheus/pushgateway.nix { };
   prometheus-rabbitmq-exporter = callPackage ../servers/monitoring/prometheus/rabbitmq-exporter.nix { };
   prometheus-snmp-exporter = callPackage ../servers/monitoring/prometheus/snmp-exporter.nix {