From 76a7480a1dba5c18247ce17be2e65cad5b63569d Mon Sep 17 00:00:00 2001
From: Noah Masur <7386960+nmasur@users.noreply.github.com>
Date: Sun, 16 Jul 2023 01:04:52 +0000
Subject: [PATCH] working prometheus setup with processes

---
 modules/nixos/hardware/zfs.nix        |  6 ++++++
 modules/nixos/services/nextcloud.nix  | 16 +++++++++++++++
 modules/nixos/services/prometheus.nix | 29 ++++++++++++++++++++++++++-
 3 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/modules/nixos/hardware/zfs.nix b/modules/nixos/hardware/zfs.nix
index dea9c42..6db46d4 100644
--- a/modules/nixos/hardware/zfs.nix
+++ b/modules/nixos/hardware/zfs.nix
@@ -10,6 +10,12 @@
         config.boot.zfs.package.latestCompatibleLinuxPackages;
       boot.kernelParams = [ "nohibernate" ];
       boot.supportedFilesystems = [ "zfs" ];
+      services.prometheus.exporters.zfs.enable = true;
+      scrapeTargets = [
+        "127.0.0.1:${
+          builtins.toString config.services.prometheus.exporters.zfs.port
+        }"
+      ];
 
     };
 
diff --git a/modules/nixos/services/nextcloud.nix b/modules/nixos/services/nextcloud.nix
index b4a3e7f..fede4c8 100644
--- a/modules/nixos/services/nextcloud.nix
+++ b/modules/nixos/services/nextcloud.nix
@@ -11,6 +11,7 @@
       config = {
         adminpassFile = config.secrets.nextcloud.dest;
         extraTrustedDomains = [ config.hostnames.content ];
+        trustedProxies = [ "127.0.0.1" ];
       };
     };
 
@@ -74,6 +75,21 @@
       requires = [ "phpfpm-nextcloud.service" ];
     };
 
+    # Log metrics to prometheus
+    services.prometheus.exporters.nextcloud = {
+      enable = true;
+      username = config.services.nextcloud.config.adminuser;
+      url = "http://localhost:8080";
+      passwordFile = config.services.nextcloud.config.adminpassFile;
+    };
+    scrapeTargets = [
+      "127.0.0.1:${
+        builtins.toString config.services.prometheus.exporters.nextcloud.port
+      }"
+    ];
+    # Allows nextcloud-exporter to read passwordFile
+    users.users.nextcloud-exporter.extraGroups = [ "nextcloud" ];
+
   };
 
 }
diff --git a/modules/nixos/services/prometheus.nix b/modules/nixos/services/prometheus.nix
index a08096d..fa026bd 100644
--- a/modules/nixos/services/prometheus.nix
+++ b/modules/nixos/services/prometheus.nix
@@ -1,5 +1,11 @@
 { config, pkgs, lib, ... }: {
 
+  options.scrapeTargets = lib.mkOption {
+    type = lib.types.listOf lib.types.str;
+    description = "Prometheus scrape targets";
+    default = [ ];
+  };
+
   config = let
 
     # If hosting Grafana, host local Prometheus and listen for inbound jobs. If
@@ -8,12 +14,33 @@
 
   in lib.mkIf config.services.prometheus.enable {
 
+    scrapeTargets = [
+      "127.0.0.1:${
+        builtins.toString config.services.prometheus.exporters.node.port
+      }"
+      "127.0.0.1:${
+        builtins.toString config.services.prometheus.exporters.systemd.port
+      }"
+      "127.0.0.1:${
+        builtins.toString config.services.prometheus.exporters.process.port
+      }"
+    ];
+
     services.prometheus = {
       exporters.node.enable = true;
+      exporters.systemd.enable = true;
+      exporters.process.enable = true;
+      exporters.process.settings.process_names = [
+        # Remove nix store path from process name
+        {
+          name = "{{.Matches.Wrapped}} {{ .Matches.Args }}";
+          cmdline = [ "^/nix/store[^ ]*/(?P<Wrapped>[^ /]*) (?P<Args>.*)" ];
+        }
+      ];
       extraFlags = lib.mkIf isServer [ "--web.enable-remote-write-receiver" ];
       scrapeConfigs = [{
         job_name = config.networking.hostName;
-        static_configs = [{ targets = [ "127.0.0.1:9100" ]; }];
+        static_configs = [{ targets = config.scrapeTargets; }];
       }];
       webExternalUrl =
         lib.mkIf isServer "https://${config.hostnames.prometheus}";