nixosModules.services.mrtg: init mrtg-generator (socallinuxexpo#923)

Author: kylerisse

nix/nixos-configurations/core-master/configuration.nix

@@ -10,6 +10,7 @@
     services.rsyslogd.enable = true;
     services.signs.enable = true;
     services.monitoring.enable = true;
+    services.mrtg.enable = true;
     services.prometheus.enable = true;
     services.ssh.enable = true;
     services.wasgeht.enable = true;

nix/nixos-modules/default.nix

@@ -7,7 +7,6 @@ inputs: {
         ./facts.nix
         ./libvirt.nix
         ./time.nix
-
         ./services
         ./users
       ];

nix/nixos-modules/services/default.nix

@@ -6,6 +6,7 @@
     ./gitlab.nix
     ./kea-master.nix
     ./monitoring.nix
+    ./mrtg.nix
     ./ntp.nix
     ./prometheus.nix
     ./rsyslogd.nix

nix/nixos-modules/services/mrtg.nix

@@ -0,0 +1,95 @@
+{
+  config,
+  pkgs,
+  lib,
+  ...
+}:
+let
+
+  cfg = config.scale-network.services.mrtg;
+
+  inherit (lib)
+    types
+    ;
+
+  inherit (lib.modules)
+    mkIf
+    ;
+
+  inherit (lib.options)
+    mkEnableOption
+    mkOption
+    ;
+in
+
+{
+
+  options.scale-network.services.mrtg = {
+
+    enable = mkEnableOption "SCaLE mrtg monitoring service";
+
+    user = mkOption {
+      type = types.str;
+      default = "mrtg";
+    };
+
+    group = mkOption {
+      type = types.str;
+      default = "mrtg";
+    };
+
+    statePath = mkOption {
+      type = types.str;
+      default = "/persist/var/lib/mrtg";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.mrtg-generator =
+      let
+        unfilteredList = (
+          builtins.split "\n" (
+            builtins.readFile "${pkgs.scale-network.scaleInventory}/config/all-network-devices"
+          )
+        );
+        filteredList = (builtins.filter (line: line != [ ] && line != "") unfilteredList);
+        script = pkgs.writeShellScript "" ''
+          set -x
+          mkdir -p ${cfg.statePath}/configs
+          mkdir -p ${cfg.statePath}/graphs
+          for hostname in ${toString filteredList}; do
+            echo "''${hostname}"
+            ${pkgs.mrtg}/bin/cfgmaker \
+            --enable-ipv6 \
+            --no-down \
+            --show-op-down \
+            --output="${cfg.statePath}/configs/''${hostname}.cfg" \
+            --global="WorkDir: ${cfg.statePath}/graphs/''${hostname}/" \
+            Junitux@''${hostname}
+          done
+        '';
+      in
+      {
+        description = "mrtg generator";
+        after = [ "network.target" ];
+        wantedBy = [ "multi-user.target" ];
+        serviceConfig = {
+          User = "${cfg.user}";
+          Group = "${cfg.group}";
+          ExecStart = "${script}";
+          Type = "simple";
+        };
+      };
+    systemd.tmpfiles.rules = [
+      "d ${cfg.statePath} 0755 ${cfg.user} ${cfg.group}"
+    ];
+
+    users = {
+      users."${cfg.user}" = {
+        isNormalUser = true;
+        group = "${cfg.group}";
+      };
+      groups.${cfg.group} = { };
+    };
+  };
+}