feat: migrate from prometheus to victoriametrics (#171)

* feat: migrate from prometheus to victoriametrics

* fix: duplicated declaration

* fix: victoriametrics - isSystemUser

* fix: import promTypes

* fix: vmalert

* fix(victoriametrics): cli args

hosts/idols-aquamarine/prometheus/README.md → hosts/idols-aquamarine/monitoring/README.md

@@ -1,4 +1,4 @@
-# Prometheus & Alertmanager
+# Monitoring & Alerting
 
 ## Alert Rules
 

hosts/idols-aquamarine/monitoring/alertmanager.nix

@@ -0,0 +1,47 @@
+{config, ...}: {
+  services.prometheus.alertmanager = {
+    enable = true;
+    listenAddress = "127.0.0.1";
+    port = 9093;
+    webExternalUrl = "http://alertmanager.writefor.fun";
+    logLevel = "info";
+
+    environmentFile = config.age.secrets."alertmanager.env".path;
+    configuration = {
+      global = {
+        # The smarthost and SMTP sender used for mail notifications.
+        smtp_smarthost = "smtp.qq.com:465";
+        smtp_from = "$SMTP_SENDER_EMAIL";
+        smtp_auth_username = "$SMTP_AUTH_USERNAME";
+        smtp_auth_password = "$SMTP_AUTH_PASSWORD";
+        # smtp.qq.com:465 support SSL only, so we need to disable TLS here.
+        # https://service.mail.qq.com/detail/0/310
+        smtp_require_tls = false;
+      };
+      route = {
+        receiver = "default";
+        routes = [
+          {
+            group_by = ["host"];
+            group_wait = "5m";
+            group_interval = "5m";
+            repeat_interval = "4h";
+            receiver = "default";
+          }
+        ];
+      };
+      receivers = [
+        {
+          name = "default";
+          email_configs = [
+            {
+              to = "[email protected]";
+              # Whether to notify about resolved alerts.
+              send_resolved = true;
+            }
+          ];
+        }
+      ];
+    };
+  };
+}

hosts/idols-aquamarine/monitoring/default.nix

@@ -0,0 +1,7 @@
+{mylib, ...}: {
+  imports = [
+    ./module
+    ./victoriametrics.nix
+    ./alertmanager.nix
+  ];
+}

hosts/idols-aquamarine/monitoring/module/default.nix

@@ -0,0 +1,195 @@
+# Based on
+# - https://github.com/NixOS/nixpkgs/blob/nixos-24.05/nixos/modules/services/databases/victoriametrics.nix
+# - https://github.com/NixOS/nixpkgs/blob/nixos-24.05/nixos/modules/services/monitoring/prometheus/default.nix
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}:
+with lib; let
+  cfg = config.services.my-victoriametrics;
+  yaml = pkgs.formats.yaml {};
+
+  promTypes = import ./promTypes.nix {inherit lib;};
+
+  bindAddr = "${cfg.listenAddress}:${builtins.toString cfg.port}";
+  workingDir = "/var/lib/" + cfg.stateDir;
+
+  generatedPrometheusYml = yaml.generate "prometheus.yml" scrapeConfig;
+
+  # This becomes the main config file for VictoriaMetrics's `-promscrape.config`
+  # https://docs.victoriametrics.com/vmagent/#how-to-collect-metrics-in-prometheus-format
+  scrapeConfig = {
+    global = filterValidPrometheus cfg.globalConfig;
+    scrape_configs = filterValidPrometheus cfg.scrapeConfigs;
+  };
+
+  filterValidPrometheus = filterAttrsListRecursive (n: v: !(n == "_module" || v == null));
+  filterAttrsListRecursive = pred: x:
+    if isAttrs x
+    then
+      listToAttrs
+      (
+        concatMap
+        (
+          name: let
+            v = x.${name};
+          in
+            if pred name v
+            then [
+              (nameValuePair name (filterAttrsListRecursive pred v))
+            ]
+            else []
+        )
+        (attrNames x)
+      )
+    else if isList x
+    then map (filterAttrsListRecursive pred) x
+    else x;
+in {
+  options.services.my-victoriametrics = {
+    enable = mkEnableOption "VictoriaMetrics, a time series database, long-term remote storage for victoriametrics";
+    package = mkPackageOption pkgs "victoriametrics" {};
+
+    port = mkOption {
+      type = types.port;
+      default = 8428;
+      description = ''
+        Port to listen on.
+      '';
+    };
+
+    listenAddress = mkOption {
+      type = types.str;
+      default = "0.0.0.0";
+      description = ''
+        Address to listen on for the http API.
+      '';
+    };
+
+    stateDir = mkOption {
+      type = types.str;
+      default = "victoriametrics2";
+      description = ''
+        Directory below `/var/lib` to store VictoriaMetrics metrics data.
+        This directory will be created automatically using systemd's StateDirectory mechanism.
+      '';
+    };
+
+    retentionTime = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      example = "15d";
+      description = ''
+        How long to retain samples in storage.
+        The minimum retentionPeriod is 24h or 1d. See also -retentionFilter
+        The following optional suffixes are supported: s (second), h (hour), d (day), w (week), y (year).
+        If suffix isn't set, then the duration is counted in months (default 1)
+      '';
+    };
+
+    globalConfig = mkOption {
+      type = promTypes.globalConfig;
+      default = {};
+      description = ''
+        Parameters that are valid in all  configuration contexts. They
+        also serve as defaults for other configuration sections
+      '';
+    };
+
+    scrapeConfigs = mkOption {
+      type = types.listOf promTypes.scrape_config;
+      default = [];
+      description = ''
+        A list of scrape configurations.
+        See docs: <https://docs.victoriametrics.com/vmagent/#how-to-collect-metrics-in-prometheus-format>
+      '';
+    };
+
+    extraFlags = mkOption {
+      type = types.listOf types.str;
+      default = [];
+      description = ''
+        Extra options to pass to VictoriaMetrics. See the README:
+        <https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md>
+        or {command}`victoriametrics -help` for more
+        information.
+      '';
+    };
+  };
+  config = lib.mkIf cfg.enable {
+    users.groups.victoriametrics = {};
+    users.users.victoriametrics = {
+      description = "victoriametrics daemon user";
+      isSystemUser = true; # required when uid is null
+      group = "victoriametrics";
+    };
+
+    systemd.services.my-victoriametrics = {
+      description = "VictoriaMetrics time series database";
+      wantedBy = ["multi-user.target"];
+      after = ["network.target"];
+
+      startLimitBurst = 5;
+      serviceConfig = {
+        ExecStart = ''
+          ${cfg.package}/bin/victoria-metrics \
+              -storageDataPath=${workingDir} \
+              -httpListenAddr=${bindAddr} \
+              -retentionPeriod=${cfg.retentionTime} \
+              -promscrape.config=${generatedPrometheusYml} \
+              ${lib.escapeShellArgs cfg.extraFlags}
+        '';
+        RestartSec = 1;
+        User = "victoriametrics";
+        Restart = "on-failure";
+        RuntimeDirectory = "victoriametrics";
+        RuntimeDirectoryMode = "0700";
+        WorkingDirectory = workingDir;
+        StateDirectory = cfg.stateDir;
+        StateDirectoryMode = "0700";
+
+        # Increase the limit to avoid errors like 'too many open files'  when merging small parts
+        LimitNOFILE = 1048576;
+
+        # Hardening
+        AmbientCapabilities = lib.mkIf (cfg.port < 1024) ["CAP_NET_BIND_SERVICE"];
+        CapabilityBoundingSet =
+          if (cfg.port < 1024)
+          then ["CAP_NET_BIND_SERVICE"]
+          else [""];
+        DeviceAllow = ["/dev/null rw"];
+        DevicePolicy = "strict";
+        LockPersonality = true;
+        MemoryDenyWriteExecute = true;
+        NoNewPrivileges = true;
+        PrivateDevices = true;
+        PrivateTmp = true;
+        PrivateUsers = true;
+        ProtectClock = true;
+        ProtectControlGroups = true;
+        ProtectHome = true;
+        ProtectHostname = true;
+        ProtectKernelLogs = true;
+        ProtectKernelModules = true;
+        ProtectKernelTunables = true;
+        ProtectProc = "invisible";
+        ProtectSystem = "full";
+        RemoveIPC = true;
+        RestrictAddressFamilies = ["AF_INET" "AF_INET6" "AF_UNIX"];
+        RestrictNamespaces = true;
+        RestrictRealtime = true;
+        RestrictSUIDSGID = true;
+        SystemCallArchitectures = "native";
+        SystemCallFilter = ["@system-service" "~@privileged"];
+      };
+
+      postStart = lib.mkBefore ''
+        until ${lib.getBin pkgs.curl}/bin/curl -s -o /dev/null http://${bindAddr}/ping; do
+          sleep 1;
+        done
+      '';
+    };
+  };
+}