From bf21b3b7c8647158d5c1377e10c9b098ad0eed56 Mon Sep 17 00:00:00 2001
From: Victor <victor@xirion.net>
Date: Fri, 29 Jul 2022 13:02:03 +0200
Subject: [PATCH] add synapse metrics

---
 nixos/common/services/vmagent.nix             | 61 ++++++++++---------
 nixos/hosts/nginx/configuration.nix           |  2 +-
 nixos/hosts/synapse/configuration.nix         | 16 ++++-
 nixos/hosts/victoriametrics/configuration.nix | 23 ++++++-
 nixos/pkgs/default.nix                        |  2 +
 nixos/pkgs/vmagent/default.nix                | 23 +++++++
 6 files changed, 95 insertions(+), 32 deletions(-)
 create mode 100644 nixos/pkgs/vmagent/default.nix

diff --git a/nixos/common/services/vmagent.nix b/nixos/common/services/vmagent.nix
index 5ca3e4c..31c2723 100644
--- a/nixos/common/services/vmagent.nix
+++ b/nixos/common/services/vmagent.nix
@@ -1,7 +1,10 @@
 { config, pkgs, lib, ... }:
 with lib;
-let cfg = config.services.vmagent;
-in {
+let
+  cfg = config.services.vmagent;
+  settingsFormat = pkgs.formats.json { };
+in
+{
   options.services.vmagent = {
     enable = mkEnableOption "vmagent";
 
@@ -22,8 +25,8 @@ in {
     };
 
     package = mkOption {
-      default = pkgs.v.vmagent;
-      defaultText = "pkgs.v.vmagent";
+      default = pkgs.vmagent;
+      defaultText = "pkgs.vmagent";
       type = types.package;
       description = ''
         vmagent package to use. 
@@ -47,16 +50,17 @@ in {
     };
 
     prometheusConfig = mkOption {
-      default = "";
-      type = types.str;
-      example = ''
-        global:
-          scrape_interval: 5s
-        scrape_configs:
-          - job_name: 'apache'
-            static_configs:
-            - targets: ['apache-exporter:9117']
-      '';
+      type = lib.types.submodule {
+        freeformType = settingsFormat.type;
+      };
+      # example = ''
+      #   global:
+      #     scrape_interval: 5s
+      #   scrape_configs:
+      #     - job_name: 'apache'
+      #       static_configs:
+      #       - targets: ['apache-exporter:9117']
+      # '';
       description = ''
         Config for prometheus style metrics
       '';
@@ -90,21 +94,22 @@ in {
     networking.firewall.allowedTCPPorts = mkIf (cfg.openFirewall) [ 8429 ];
 
     # The actual service
-    systemd.services.vmagent = let prometheusConfig = pkgs.writeText "prometheus.yml" cfg.prometheusConfig;
-    in {
-      wantedBy = [ "multi-user.target" ];
-      after = [ "network.target" ];
-      description = "vmagent system service";
-      serviceConfig = {
-        User = cfg.user;
-        Group = cfg.group;
-        Type = "simple";
-        Restart = "on-failure";
-        WorkingDirectory = cfg.dataDir;
-        ExecStart =
-          "${cfg.package}/bin/vmagent -remoteWrite.url=${cfg.remoteWriteUrl} -promscrape.config=${prometheusConfig}";
+    systemd.services.vmagent =
+      let prometheusConfig = settingsFormat.generate "prometheusConfig.yaml" cfg.prometheusConfig;
+      in {
+        wantedBy = [ "multi-user.target" ];
+        after = [ "network.target" ];
+        description = "vmagent system service";
+        serviceConfig = {
+          User = cfg.user;
+          Group = cfg.group;
+          Type = "simple";
+          Restart = "on-failure";
+          WorkingDirectory = cfg.dataDir;
+          ExecStart =
+            "${cfg.package}/bin/vmagent -remoteWrite.url=${cfg.remoteWriteUrl} -promscrape.config=${prometheusConfig}";
+        };
       };
-    };
 
     systemd.tmpfiles.rules = [ "d '${cfg.dataDir}' 0755 ${cfg.user} ${cfg.group} -" ];
   };
diff --git a/nixos/hosts/nginx/configuration.nix b/nixos/hosts/nginx/configuration.nix
index 170a2ce..c11fa6a 100644
--- a/nixos/hosts/nginx/configuration.nix
+++ b/nixos/hosts/nginx/configuration.nix
@@ -62,7 +62,7 @@ in
       forceSSL = true;
       locations."/".extraConfig = ''
         add_header Content-Type 'text/html; charset=UTF-8';
-        return 200 meow;
+        return 200 '<h1>meow</h1>';
       '';
       locations."= /.well-known/matrix/client".extraConfig = mkWellKnown clientConfig;
       locations."= /.well-known/matrix/server".extraConfig = mkWellKnown serverConfig;
diff --git a/nixos/hosts/synapse/configuration.nix b/nixos/hosts/synapse/configuration.nix
index 677003f..84d2e72 100644
--- a/nixos/hosts/synapse/configuration.nix
+++ b/nixos/hosts/synapse/configuration.nix
@@ -6,6 +6,7 @@
 let
   vs = config.vault-secrets.secrets;
   port = 8008;
+  metricsPort = 9000;
 in
 {
   imports = [ ];
@@ -23,7 +24,7 @@ in
   # Additional packages
   environment.systemPackages = with pkgs; [ ];
 
-  networking.firewall.allowedTCPPorts = [ port ];
+  networking.firewall.allowedTCPPorts = [ port metricsPort ];
 
   vault-secrets.secrets.synapse = {
     user = "matrix-synapse";
@@ -65,6 +66,7 @@ in
           server_name = "meowy.tech";
           enable_registration = true;
           public_baseurl = "https://chat.meowy.tech";
+          enable_metrics = true;
           listeners = [
             {
               inherit port;
@@ -79,6 +81,18 @@ in
                 }
               ];
             }
+            {
+              port = metricsPort;
+              bind_addresses = [ "0.0.0.0" ];
+              type = "metrics";
+              tls = false;
+              resources = [
+                {
+                  names = [ "metrics" ];
+                  compress = false;
+                }
+              ];
+            }
           ];
         };
     };
diff --git a/nixos/hosts/victoriametrics/configuration.nix b/nixos/hosts/victoriametrics/configuration.nix
index 6d4b4d2..5fd0532 100644
--- a/nixos/hosts/victoriametrics/configuration.nix
+++ b/nixos/hosts/victoriametrics/configuration.nix
@@ -6,7 +6,8 @@
 let
   vmPort = 8428;
   vs = config.vault-secrets.secrets;
-in {
+in
+{
   imports = [ ];
 
   networking.hostName = "victoriametrics";
@@ -32,7 +33,25 @@ in {
     retentionPeriod = 12;
   };
 
-  vault-secrets.secrets.grafana = { 
+  services.vmagent = {
+    enable = true;
+    openFirewall = true;
+    prometheusConfig = {
+      global.scrape_interval = "5s";
+      scrape_configs = [
+        {
+          job_name = "synapse";
+          metrics_path = "/_synapse/metrics";
+          static_configs = [{
+            targets = [ "synapse.olympus:9000" ];
+            labels.app = "synapse";
+          }];
+        }
+      ];
+    };
+  };
+
+  vault-secrets.secrets.grafana = {
     user = "grafana";
     group = "grafana";
   };
diff --git a/nixos/pkgs/default.nix b/nixos/pkgs/default.nix
index feb82c2..f933374 100644
--- a/nixos/pkgs/default.nix
+++ b/nixos/pkgs/default.nix
@@ -6,6 +6,8 @@ final: prev: {
     '';
   });
 
+  vmagent = prev.callPackage ./vmagent { };
+
   v = {
     unbound = prev.unbound.override {
       withSystemd = true;
diff --git a/nixos/pkgs/vmagent/default.nix b/nixos/pkgs/vmagent/default.nix
new file mode 100644
index 0000000..2a1984d
--- /dev/null
+++ b/nixos/pkgs/vmagent/default.nix
@@ -0,0 +1,23 @@
+{ lib, fetchFromGitHub, buildGoModule }:
+buildGoModule rec {
+  pname = "vmagent";
+  version = "1.79.0";
+
+  src = fetchFromGitHub {
+    owner = "VictoriaMetrics";
+    repo = "VictoriaMetrics";
+    rev = "v${version}";
+    sha256 = "sha256-+LirbGbKeazXMtgVh5kZP+KEk/fDbSxceZ26OlE0hbY=";
+  };
+
+  vendorSha256 = null;
+
+  subPackages = [ "app/vmagent" ];
+
+  meta = with lib; {
+    description = "VictoriaMetrics metrics scraper";
+    homepage = "https://github.com/VictoriaMetrics/VictoriaMetrics/tree/master/app/vmagent";
+    license = licenses.asl20;
+    platforms = platforms.linux;
+  };
+}