Add monitoring modules via naemon

[perso/Immae/Config/Nix.git] / modules / naemon / default.nix

diff --git a/modules/naemon/default.nix b/modules/naemon/default.nix
new file mode 100644 (file)
index 0000000..38e99a9
--- /dev/null
+++ b/modules/naemon/default.nix
@@ -0,0 +1,184 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.naemon;
+
+  naemonConfig = pkgs.runCommand "naemon-config" {
+    objectsFile = pkgs.writeText "naemon_objects.cfg" cfg.objectDefs;
+    resourceFile = config.secrets.fullPaths."naemon/resources.cfg";
+    extraConfig = pkgs.writeText "extra.cfg" cfg.extraConfig;
+    inherit (cfg) logDir varDir runDir cacheDir;
+  } ''
+     substituteAll ${./naemon.cfg} $out
+     cat $extraConfig >> $out
+    '';
+in
+{
+  options = {
+    services.naemon = {
+      enable = mkOption {
+        default = false;
+        description = "
+          Whether to use <link
+          xlink:href='http://www.naemon.org/'>Naemon</link> to monitor
+          your system or network.
+        ";
+      };
+
+      objectDefs = mkOption {
+        type = types.lines;
+        default = "";
+        description = "
+          A list of Naemon object configuration that must define
+          the hosts, host groups, services and contacts for the
+          network that you want Naemon to monitor.
+        ";
+      };
+
+      extraResource = mkOption {
+        type = types.lines;
+        default = "";
+        example = ''
+            # Sets $USER2$ to be the path to event handlers
+            #$USER2$=/usr/lib/monitoring-plugins/eventhandlers
+
+            # Store some usernames and passwords (hidden from the CGIs)
+            #$USER3$=someuser
+            #$USER4$=somepassword
+          '';
+        description = "
+          Lines to add to the resource file
+            # You can define $USERx$ macros in this file, which can in turn be used
+            # in command definitions in your host config file(s).  $USERx$ macros are
+            # useful for storing sensitive information such as usernames, passwords,
+            # etc.  They are also handy for specifying the path to plugins and
+            # event handlers - if you decide to move the plugins or event handlers to
+            # a different directory in the future, you can just update one or two
+            # $USERx$ macros, instead of modifying a lot of command definitions.
+            #
+            # Naemon supports up to 256 $USERx$ macros ($USER1$ through $USER256$)
+            #
+            # Resource files may also be used to store configuration directives for
+            # external data sources like MySQL...
+            #
+        ";
+      };
+
+      extraConfig = mkOption {
+        type = types.lines;
+        default = "";
+        description = "
+          Extra config to append to main config
+        ";
+      };
+
+      user = mkOption {
+        type = types.str;
+        default = "naemon";
+        description = "User for naemon";
+      };
+
+      group = mkOption {
+        type = types.str;
+        default = "naemon";
+        description = "Group for naemon";
+      };
+
+      varDir = mkOption {
+        type = types.path;
+        default = "/var/lib/naemon";
+        description = "The directory where naemon stores its data";
+      };
+
+      cacheDir = mkOption {
+        type = types.path;
+        default = "/var/cache/naemon";
+        description = "The directory where naemon stores its cache";
+      };
+
+      runDir = mkOption {
+        type = types.path;
+        default = "/run/naemon";
+        description = "The directory where naemon stores its runtime files";
+      };
+
+      logDir = mkOption {
+        type = types.path;
+        default = "/var/log/naemon";
+        description = "The directory where naemon stores its log files";
+      };
+
+      package = mkOption {
+        type = types.package;
+        default = pkgs.naemon.override {
+          inherit (cfg) varDir cacheDir logDir runDir user group;
+        };
+        description  = ''
+          Naemon package to use
+          '';
+      };
+    };
+  };
+
+
+  config = mkIf cfg.enable {
+    secrets.keys = [
+      {
+        dest = "naemon/resources.cfg";
+        user = cfg.user;
+        group = cfg.group;
+        permissions = "0400";
+        text = ''
+          $USER1$=${pkgs.monitoring-plugins}/libexec
+          ${cfg.extraResource}
+          '';
+      }
+    ];
+
+    users.users = optionalAttrs (cfg.user == "naemon") (singleton
+      {
+        name = "naemon";
+        group = cfg.group;
+        uid   = config.ids.uids.nagios;
+        extraGroups = [ "keys" ];
+      });
+    users.groups = optionalAttrs (cfg.user == "naemon") (singleton
+      {
+        name = "naemon";
+        gid   = config.ids.gids.nagios;
+      });
+
+    services.filesWatcher.naemon = {
+      paths = [ config.secrets.fullPaths."naemon/resources.cfg" ];
+    };
+    systemd.services.naemon = {
+      description = "Naemon monitoring daemon";
+      path     = [ cfg.package pkgs.monitoring-plugins ];
+      wantedBy = [ "multi-user.target" ];
+      after    = [ "network.target" ];
+
+      preStart = "${cfg.package}/bin/naemon -vp ${naemonConfig}";
+      script = "${cfg.package}/bin/naemon --daemon ${naemonConfig}";
+      reload = "${pkgs.utillinux}/bin/kill -HUP $MAINPID";
+      serviceConfig = {
+        User = cfg.user;
+        Restart = "always";
+        RestartSec = 2;
+        StandardOutput = "journal";
+        StandardError = "inherit";
+        PIDFile = "${cfg.runDir}/naemon.pid";
+        LogsDirectory = assert lib.strings.hasPrefix "/var/log/" cfg.logDir;
+          lib.strings.removePrefix "/var/log/" cfg.logDir;
+        CacheDirectory = assert lib.strings.hasPrefix "/var/cache/" cfg.cacheDir;
+          let unprefixed = lib.strings.removePrefix "/var/cache/" cfg.cacheDir;
+          in [ unprefixed "${unprefixed}/checkresults" ];
+        StateDirectory = assert lib.strings.hasPrefix "/var/lib/" cfg.varDir;
+          lib.strings.removePrefix "/var/lib/" cfg.varDir;
+        RuntimeDirectory = assert lib.strings.hasPrefix "/run/" cfg.runDir;
+          lib.strings.removePrefix "/run/" cfg.runDir;
+      };
+    };
+  };
+}