#!rsc by RouterOS
# RouterOS script: netwatch-notify
# Copyright (c) 2020-2024 Christian Hesse <mail@eworm.de>
# https://git.eworm.de/cgit/routeros-scripts/about/COPYING.md
#
# requires RouterOS, version=7.15
#
# monitor netwatch and send notifications
# https://git.eworm.de/cgit/routeros-scripts/about/doc/netwatch-notify.md

:global GlobalFunctionsReady;
:while ($GlobalFunctionsReady != true) do={ :delay 500ms; }

:local ExitOK false;
:do {
  :local ScriptName [ :jobname ];

  :global NetwatchNotify;

  :global EitherOr;
  :global IfThenElse;
  :global IsDNSResolving;
  :global LogPrint;
  :global ParseKeyValueStore;
  :global ScriptFromTerminal;
  :global ScriptLock;
  :global SendNotification2;
  :global SymbolForNotification;

  :local NetwatchNotifyHook do={
    :local ScriptName [ :tostr $1 ];
    :local Name       [ :tostr $2 ];
    :local Type       [ :tostr $3 ];
    :local State      [ :tostr $4 ];
    :local Hook       [ :tostr $5 ];

    :global LogPrint;
    :global ValidateSyntax;

    :if ([ $ValidateSyntax $Hook ] = true) do={
      :do {
        [ :parse $Hook ];
      } on-error={
        $LogPrint warning $ScriptName ("The " . $State . "-hook for " . $Type . " '" . $Name . "' failed to run.");
        :return ("The hook failed to run.");
      }
    } else={
      $LogPrint warning $ScriptName ("The " . $State . "-hook for " . $Type . " '" . $Name . "' failed syntax validation.");
      :return ("The hook failed syntax validation.");
    }

    $LogPrint info $ScriptName ("Ran hook on " . $Type . " '" . $Name . "' " . $State . ": " . $Hook);
    :return ("Ran hook:\n" . $Hook);
  }

  :local ResolveExpected do={
    :local ScriptName [ :tostr $1 ];
    :local Name       [ :tostr $2 ];
    :local Expected   [ :tostr $3 ];

    :global GetRandom20CharAlNum;

    :local FwAddrList ($ScriptName . "-" . [ $GetRandom20CharAlNum ]);
    /ip/firewall/address-list/add address=$Name list=$FwAddrList dynamic=yes timeout=1s;
    :delay 20ms;
    :if ([ :len [ /ip/firewall/address-list/find where list=$FwAddrList address=$Expected ] ] > 0) do={
      :return true;
    }
    /ipv6/firewall/address-list/add address=$Name list=$FwAddrList dynamic=yes timeout=1s;
    :delay 20ms;
    :if ([ :len [ /ipv6/firewall/address-list/find where list=$FwAddrList address=$Expected ] ] > 0) do={
      :return true;
    }

    :return false;
  }

  :if ([ $ScriptLock $ScriptName ] = false) do={
    :set ExitOK true;
    :error false;
  }

  :local ScriptFromTerminalCached [ $ScriptFromTerminal $ScriptName ];

  :if ([ :typeof $NetwatchNotify ] = "nothing") do={
    :set NetwatchNotify ({});
  }

  :foreach Host in=[ /tool/netwatch/find where comment~"\\bnotify\\b" !disabled status!="unknown" ] do={
    :local HostVal [ /tool/netwatch/get $Host ];
    :local Type [ $IfThenElse ($HostVal->"type" ~ "^(https?-get|tcp-conn)\$") "service" "host" ];
    :local HostInfo [ $ParseKeyValueStore ($HostVal->"comment") ];
    :local HostDetails ($HostVal->"host" . \
        [ $IfThenElse ([ :len ($HostInfo->"resolve") ] > 0) (", " . $HostInfo->"resolve") ]);

    :if ($HostInfo->"notify" = true && $HostInfo->"disabled" != true) do={
      :local Name [ $EitherOr ($HostInfo->"name") ($HostVal->"name") ];

      :local Metric { "count-down"=0; "count-up"=0; "notified"=false; "resolve-failcnt"=0 };
      :if ([ :typeof ($NetwatchNotify->$Name) ] = "array") do={
        :set $Metric ($NetwatchNotify->$Name);
      }

      :if ([ :typeof ($HostInfo->"resolve") ] = "str") do={
        :if ([ $IsDNSResolving ] = true) do={
          :do {
            :local Resolve [ :resolve type=[ $IfThenElse ([ :typeof ($HostVal->"host") ] = "ip") \
                "ipv4" "ipv6" ] ($HostInfo->"resolve") ];
            :if ($Resolve != $HostVal->"host") do={
              :if ([ $ResolveExpected $ScriptName ($HostInfo->"resolve") ($HostVal->"host") ] = false) do={
                $LogPrint info $ScriptName ("Name '" . $HostInfo->"resolve" . [ $IfThenElse \
                    ($HostInfo->"resolve" != $HostInfo->"name") ("' for " . $Type . " '" . \
                    $HostInfo->"name") "" ] . "' resolves to different address " . $Resolve . \
                    ", updating.");
                /tool/netwatch/set host=$Resolve $Host;
                :set ($Metric->"resolve-failcnt") 0;
                :set ($HostVal->"status") "unknown";
              }
            }
          } on-error={
            :set ($Metric->"resolve-failcnt") ($Metric->"resolve-failcnt" + 1);
            :if ($Metric->"resolve-failcnt" = 3) do={
              $LogPrint [ $IfThenElse ($HostInfo->"no-resolve-fail" != true) warning debug ] \
                  $ScriptName ("Resolving name '" . $HostInfo->"resolve" . [ $IfThenElse \
                  ($HostInfo->"resolve" != $HostInfo->"name") ("' for " . $Type . " '" . \
                  $HostInfo->"name") "" ] . "' failed.");
            }
          }
        }
      }

      :if ($HostVal->"status" = "up") do={
        :local CountDown ($Metric->"count-down");
        :if ($CountDown > 0) do={
          $LogPrint info $ScriptName \
              ("The " . $Type . " '" . $Name . "' (" . $HostDetails . ") is up.");
          :set ($Metric->"count-down") 0;
        }
        :set ($Metric->"count-up") ($Metric->"count-up" + 1);
        :if ($Metric->"notified" = true) do={
          :local Message ("The " . $Type . " '" . $Name . "' (" . $HostDetails . \
              ") is up since " . $HostVal->"since" . ".\n" . \
              "It was down for " . $CountDown . " checks since " . ($Metric->"since") . ".");
          :if ([ :typeof ($HostInfo->"note") ] = "str") do={
            :set Message ($Message . "\n\nNote:\n" . ($HostInfo->"note"));
          }
          :if ([ :typeof ($HostInfo->"up-hook") ] = "str") do={
            :set Message ($Message . "\n\n" . [ $NetwatchNotifyHook $ScriptName $Name $Type "up" \
                ($HostInfo->"up-hook") ]);
          }
          $SendNotification2 ({ origin=[ $EitherOr ($HostInfo->"origin") $ScriptName ]; silent=($HostInfo->"silent"); \
            subject=([ $SymbolForNotification "white-heavy-check-mark" ] . "Netwatch Notify: " . $Name . " up"); \
            message=$Message; link=($HostInfo->"link") });
        }
        :set ($Metric->"notified") false;
        :set ($Metric->"parent") ($HostInfo->"parent");
        :set ($Metric->"since");
      }

      :if ($HostVal->"status" = "down") do={
        :set ($Metric->"count-down") ($Metric->"count-down" + 1);
        :set ($Metric->"count-up") 0;
        :set ($Metric->"parent") ($HostInfo->"parent");
        :set ($Metric->"since") ($HostVal->"since");
        :local CountDown [ $IfThenElse ([ :tonum ($HostInfo->"count") ] > 0) ($HostInfo->"count") 5 ];
        :local Parent ($HostInfo->"parent");
        :local ParentUp false;
        :while ([ :len $Parent ] > 0) do={
          :set CountDown ($CountDown + 1);
          :set Parent ($NetwatchNotify->$Parent->"parent");
        }
        :set Parent ($HostInfo->"parent");
        :local ParentNotified false;
        :while ($ParentNotified = false && [ :len $Parent ] > 0) do={
          :set ParentNotified [ $IfThenElse (($NetwatchNotify->$Parent->"notified") = true) \
              true false ];
          :set ParentUp ($NetwatchNotify->$Parent->"count-up");
          :if ($ParentNotified = false) do={
            :set Parent ($NetwatchNotify->$Parent->"parent");
          }
        }
        :if ($Metric->"notified" = false || $Metric->"count-down" % 120 = 0 || \
             $ScriptFromTerminalCached = true) do={
          $LogPrint [ $IfThenElse ($HostInfo->"no-down-notification" != true) info debug ] $ScriptName \
              ("The " . $Type . " '" . $Name . "' (" . $HostDetails . ") is down for " . \
              $Metric->"count-down" . " checks, " . [ $IfThenElse ($ParentNotified = false) [ $IfThenElse \
              ($Metric->"notified" = true) ("already notified.") ($CountDown - $Metric->"count-down" . \
              " to go.") ] ("parent " . $Type . " " . $Parent . " is down.") ]);
        }
        :if ((($CountDown * 2) - ($Metric->"count-down" * 3)) / 2 = 0 && \
             [ :typeof ($HostInfo->"pre-down-hook") ] = "str") do={
          $NetwatchNotifyHook $ScriptName $Name $Type "pre-down" ($HostInfo->"pre-down-hook");
        }
        :if ($ParentNotified = false && $Metric->"count-down" >= $CountDown && \
             ($ParentUp = false || $ParentUp > 2) && $Metric->"notified" != true) do={
          :local Message ("The " . $Type . " '" . $Name . "' (" . $HostDetails . \
              ") is down since " . $HostVal->"since" . ".");
          :if ([ :typeof ($HostInfo->"note") ] = "str") do={
            :set Message ($Message . "\n\nNote:\n" . ($HostInfo->"note"));
          }
          :if ([ :typeof ($HostInfo->"down-hook") ] = "str") do={
            :set Message ($Message . "\n\n" . [ $NetwatchNotifyHook $ScriptName $Name $Type "down" \
                ($HostInfo->"down-hook") ]);
          }
          :if ($HostInfo->"no-down-notification" != true) do={
            $SendNotification2 ({ origin=[ $EitherOr ($HostInfo->"origin") $ScriptName ]; silent=($HostInfo->"silent"); \
              subject=([ $SymbolForNotification "cross-mark" ] . "Netwatch Notify: " . $Name . " down"); \
              message=$Message; link=($HostInfo->"link") });
          }
          :set ($Metric->"notified") true;
        }
      }

      :set ($NetwatchNotify->$Name) {
        "count-down"=($Metric->"count-down");
        "count-up"=($Metric->"count-up");
        "notified"=($Metric->"notified");
        "parent"=($Metric->"parent");
        "resolve-failcnt"=($Metric->"resolve-failcnt");
        "since"=($Metric->"since") };
    }
  }
} on-error={
  :global ExitError; $ExitError $ExitOK [ :jobname ];
}