1 files changed, 160 insertions, 0 deletions
diff --git a/nixpkgs/nixos/modules/services/monitoring/longview.nix b/nixpkgs/nixos/modules/services/monitoring/longview.nix
new file mode 100644
index 00000000000..9c38956f9ba
--- /dev/null
+++ b/nixpkgs/nixos/modules/services/monitoring/longview.nix
@@ -0,0 +1,160 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.longview;
+
+  runDir = "/run/longview";
+  configsDir = "${runDir}/longview.d";
+
+in {
+  options = {
+
+    services.longview = {
+
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          If enabled, system metrics will be sent to Linode LongView.
+        '';
+      };
+
+      apiKey = mkOption {
+        type = types.str;
+        default = "";
+        example = "01234567-89AB-CDEF-0123456789ABCDEF";
+        description = ''
+          Longview API key. To get this, look in Longview settings which
+          are found at https://manager.linode.com/longview/.
+
+          Warning: this secret is stored in the world-readable Nix store!
+          Use <option>apiKeyFile</option> instead.
+        '';
+      };
+
+      apiKeyFile = mkOption {
+        type = types.nullOr types.path;
+        default = null;
+        example = "/run/keys/longview-api-key";
+        description = ''
+          A file containing the Longview API key.
+          To get this, look in Longview settings which
+          are found at https://manager.linode.com/longview/.
+
+          <option>apiKeyFile</option> takes precedence over <option>apiKey</option>.
+        '';
+      };
+
+      apacheStatusUrl = mkOption {
+        type = types.str;
+        default = "";
+        example = "http://127.0.0.1/server-status";
+        description = ''
+          The Apache status page URL. If provided, Longview will
+          gather statistics from this location. This requires Apache
+          mod_status to be loaded and enabled.
+        '';
+      };
+
+      nginxStatusUrl = mkOption {
+        type = types.str;
+        default = "";
+        example = "http://127.0.0.1/nginx_status";
+        description = ''
+          The Nginx status page URL. Longview will gather statistics
+          from this URL. This requires the Nginx stub_status module to
+          be enabled and configured at the given location.
+        '';
+      };
+
+      mysqlUser = mkOption {
+        type = types.str;
+        default = "";
+        description = ''
+          The user for connecting to the MySQL database. If provided,
+          Longview will connect to MySQL and collect statistics about
+          queries, etc. This user does not need to have been granted
+          any extra privileges.
+        '';
+      };
+
+      mysqlPassword = mkOption {
+        type = types.str;
+        default = "";
+        description = ''
+          The password corresponding to <option>mysqlUser</option>.
+          Warning: this is stored in cleartext in the Nix store!
+          Use <option>mysqlPasswordFile</option> instead.
+        '';
+      };
+
+      mysqlPasswordFile = mkOption {
+        type = types.nullOr types.path;
+        default = null;
+        example = "/run/keys/dbpassword";
+        description = ''
+          A file containing the password corresponding to <option>mysqlUser</option>.
+        '';
+      };
+
+    };
+
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.longview =
+      { description = "Longview Metrics Collection";
+        after = [ "network.target" ];
+        wantedBy = [ "multi-user.target" ];
+        serviceConfig.Type = "forking";
+        serviceConfig.ExecStop = "-${pkgs.coreutils}/bin/kill -TERM $MAINPID";
+        serviceConfig.ExecReload = "-${pkgs.coreutils}/bin/kill -HUP $MAINPID";
+        serviceConfig.PIDFile = "${runDir}/longview.pid";
+        serviceConfig.ExecStart = "${pkgs.longview}/bin/longview";
+        preStart = ''
+          umask 077
+          mkdir -p ${configsDir}
+        '' + (optionalString (cfg.apiKeyFile != null) ''
+          cp --no-preserve=all "${cfg.apiKeyFile}" ${runDir}/longview.key
+        '') + (optionalString (cfg.apacheStatusUrl != "") ''
+          cat > ${configsDir}/Apache.conf <<EOF
+          location ${cfg.apacheStatusUrl}?auto
+          EOF
+        '') + (optionalString (cfg.mysqlUser != "" && cfg.mysqlPasswordFile != null) ''
+          cat > ${configsDir}/MySQL.conf <<EOF
+          username ${cfg.mysqlUser}
+          password `head -n1 "${cfg.mysqlPasswordFile}"`
+          EOF
+        '') + (optionalString (cfg.nginxStatusUrl != "") ''
+          cat > ${configsDir}/Nginx.conf <<EOF
+          location ${cfg.nginxStatusUrl}
+          EOF
+        '');
+      };
+
+    warnings = let warn = k: optional (cfg.${k} != "")
+                 "config.services.longview.${k} is insecure. Use ${k}File instead.";
+               in concatMap warn [ "apiKey" "mysqlPassword" ];
+
+    assertions = [
+      { assertion = cfg.apiKeyFile != null;
+        message = "Longview needs an API key configured";
+      }
+    ];
+
+    # Create API key file if not configured.
+    services.longview.apiKeyFile = mkIf (cfg.apiKey != "")
+      (mkDefault (toString (pkgs.writeTextFile {
+        name = "longview.key";
+        text = cfg.apiKey;
+      })));
+
+    # Create MySQL password file if not configured.
+    services.longview.mysqlPasswordFile = mkDefault (toString (pkgs.writeTextFile {
+      name = "mysql-password-file";
+      text = cfg.mysqlPassword;
+    }));
+  };
+}