From 1a821e7bf5254d84679273dd2f2e8f74f958d871 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ga=C3=ABl=20Reyrol?= <me@gaelreyrol.dev>
Date: Wed, 28 Jun 2023 20:57:01 +0200
Subject: [PATCH] nixos/prometheus-exporters: add php-fpm

---
 .../monitoring/prometheus/exporters.nix       |  1 +
 .../prometheus/exporters/php-fpm.nix          | 65 +++++++++++++++++++
 nixos/tests/prometheus-exporters.nix          | 43 +++++++++++-
 3 files changed, 108 insertions(+), 1 deletion(-)
 create mode 100644 nixos/modules/services/monitoring/prometheus/exporters/php-fpm.nix

diff --git a/nixos/modules/services/monitoring/prometheus/exporters.nix b/nixos/modules/services/monitoring/prometheus/exporters.nix
index 46bf7548e95e..9e3109dc0cbd 100644
--- a/nixos/modules/services/monitoring/prometheus/exporters.nix
+++ b/nixos/modules/services/monitoring/prometheus/exporters.nix
@@ -56,6 +56,7 @@ let
     "nut"
     "openldap"
     "openvpn"
+    "php-fpm"
     "pihole"
     "postfix"
     "postgres"
diff --git a/nixos/modules/services/monitoring/prometheus/exporters/php-fpm.nix b/nixos/modules/services/monitoring/prometheus/exporters/php-fpm.nix
new file mode 100644
index 000000000000..8f6942002f79
--- /dev/null
+++ b/nixos/modules/services/monitoring/prometheus/exporters/php-fpm.nix
@@ -0,0 +1,65 @@
+{ config
+, lib
+, pkgs
+, options
+}:
+
+let
+  logPrefix = "services.prometheus.exporter.php-fpm";
+  cfg = config.services.prometheus.exporters.php-fpm;
+in {
+  port = 9253;
+  extraOpts = {
+    package = lib.mkPackageOptionMD pkgs "prometheus-php-fpm-exporter" {};
+
+    telemetryPath = lib.mkOption {
+      type = lib.types.str;
+      default = "/metrics";
+      description = lib.mdDoc ''
+        Path under which to expose metrics.
+      '';
+    };
+
+    environmentFile = lib.mkOption {
+      type = lib.types.nullOr lib.types.path;
+      default = null;
+      example = "/root/prometheus-php-fpm-exporter.env";
+      description = lib.mdDoc ''
+        Environment file as defined in {manpage}`systemd.exec(5)`.
+
+        Secrets may be passed to the service without adding them to the
+        world-readable Nix store, by specifying placeholder variables as
+        the option value in Nix and setting these variables accordingly in the
+        environment file.
+
+        Environment variables from this file will be interpolated into the
+        config file using envsubst with this syntax:
+        `$ENVIRONMENT ''${VARIABLE}`
+
+        For variables to use see [options and defaults](https://github.com/hipages/php-fpm_exporter#options-and-defaults).
+
+        The main use is to set the PHP_FPM_SCRAPE_URI that indicate how to connect to PHP-FPM process.
+
+        ```
+          # Content of the environment file
+          PHP_FPM_SCRAPE_URI="unix:///tmp/php.sock;/status"
+        ```
+
+        Note that this file needs to be available on the host on which
+        this exporter is running.
+      '';
+    };
+  };
+
+  serviceOpts = {
+    serviceConfig = {
+      EnvironmentFile = lib.mkIf (cfg.environmentFile != null) [ cfg.environmentFile ];
+      ExecStart = ''
+        ${lib.getExe cfg.package} server \
+          --web.listen-address ${cfg.listenAddress}:${toString cfg.port} \
+          --web.telemetry-path ${cfg.telemetryPath} \
+          ${lib.concatStringsSep " \\\n  " cfg.extraFlags}
+      '';
+    };
+  };
+}
diff --git a/nixos/tests/prometheus-exporters.nix b/nixos/tests/prometheus-exporters.nix
index 772067b520c8..23740dd98e3d 100644
--- a/nixos/tests/prometheus-exporters.nix
+++ b/nixos/tests/prometheus-exporters.nix
@@ -6,7 +6,7 @@
 let
   inherit (import ../lib/testing-python.nix { inherit system pkgs; }) makeTest;
   inherit (pkgs.lib) concatStringsSep maintainers mapAttrs mkMerge
-    removeSuffix replaceStrings singleton splitString;
+    removeSuffix replaceStrings singleton splitString makeBinPath;
 
   /*
     * The attrset `exporterTests` contains one attribute
@@ -914,6 +914,47 @@ let
       '';
     };
 
+    php-fpm = {
+      nodeName = "php_fpm";
+      exporterConfig = {
+        enable = true;
+        environmentFile = pkgs.writeTextFile {
+          name = "/tmp/prometheus-php-fpm-exporter.env";
+          text = ''
+            PHP_FPM_SCRAPE_URI="tcp://127.0.0.1:9000/status"
+          '';
+        };
+      };
+      metricProvider = {
+        users.users."php-fpm-exporter" = {
+          isSystemUser = true;
+          group  = "php-fpm-exporter";
+        };
+        users.groups."php-fpm-exporter" = {};
+        services.phpfpm.pools."php-fpm-exporter" = {
+          user = "php-fpm-exporter";
+          group = "php-fpm-exporter";
+          settings = {
+            "pm" = "dynamic";
+            "pm.max_children" = 32;
+            "pm.max_requests" = 500;
+            "pm.start_servers" = 2;
+            "pm.min_spare_servers" = 2;
+            "pm.max_spare_servers" = 5;
+            "pm.status_path" = "/status";
+            "listen" = "127.0.0.1:9000";
+            "listen.allowed_clients" = "127.0.0.1";
+          };
+          phpEnv."PATH" = makeBinPath [ pkgs.php ];
+        };
+      };
+      exporterTest = ''
+        wait_for_unit("phpfpm-php-fpm-exporter.service")
+        wait_for_unit("prometheus-php-fpm-exporter.service")
+        succeed("curl -sSf http://localhost:9253/metrics | grep 'phpfpm_up{.*} 1'")
+      '';
+    };
+
     postfix = {
       exporterConfig = {
         enable = true;