victoriametrics: add module, tests

nixos/modules/module-list.nix

@@ -279,6 +279,7 @@
   ./services/databases/riak.nix
   ./services/databases/riak-cs.nix
   ./services/databases/stanchion.nix
+  ./services/databases/victoriametrics.nix
   ./services/databases/virtuoso.nix
   ./services/desktops/accountsservice.nix
   ./services/desktops/bamf.nix

nixos/modules/services/databases/victoriametrics.nix

@@ -0,0 +1,70 @@
+{ config, pkgs, lib, ... }:
+let cfg = config.services.victoriametrics; in
+{
+  options.services.victoriametrics = with lib; {
+    enable = mkEnableOption "victoriametrics";
+    package = mkOption {
+      type = types.package;
+      default = pkgs.victoriametrics;
+      defaultText = "pkgs.victoriametrics";
+      description = ''
+        The VictoriaMetrics distribution to use.
+      '';
+    };
+    listenAddress = mkOption {
+      default = ":8428";
+      type = types.str;
+      description = ''
+        The listen address for the http interface.
+      '';
+    };
+    retentionPeriod = mkOption {
+      type = types.int;
+      default = 1;
+      description = ''
+        Retention period in months.
+      '';
+    };
+    extraOptions = mkOption {
+      type = types.listOf types.str;
+      default = [];
+      description = ''
+        Extra options to pass to VictoriaMetrics. See the README: <link
+        xlink:href="https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md" />
+        or <command>victoriametrics -help</command> for more
+        information.
+      '';
+    };
+  };
+  config = lib.mkIf cfg.enable {
+    systemd.services.victoriametrics = {
+      description = "VictoriaMetrics time series database";
+      after = [ "network.target" ];
+      serviceConfig = {
+        Restart = "on-failure";
+        RestartSec = 1;
+        StartLimitBurst = 5;
+        StateDirectory = "victoriametrics";
+        DynamicUser = true;
+        ExecStart = ''
+          ${cfg.package}/bin/victoria-metrics \
+              -storageDataPath=/var/lib/victoriametrics \
+              -httpListenAddr ${cfg.listenAddress}
+              -retentionPeriod ${toString cfg.retentionPeriod}
+              ${lib.escapeShellArgs cfg.extraOptions}
+        '';
+      };
+      wantedBy = [ "multi-user.target" ];
+
+      postStart =
+        let
+          bindAddr = (lib.optionalString (lib.hasPrefix ":" cfg.listenAddress) "127.0.0.1") + cfg.listenAddress;
+        in
+        lib.mkBefore ''
+          until ${lib.getBin pkgs.curl}/bin/curl -s -o /dev/null http://${bindAddr}/ping; do
+            sleep 1;
+          done
+        '';
+    };
+  };
+}