ntopng/scripts/lua/modules/alert_endpoints/slack.lua
2018-07-09 19:19:24 +02:00

107 lines
3.1 KiB
Lua

--
-- (C) 2018 - ntop.org
--
require "lua_utils"
local json = require "dkjson"
local slack = {}
slack.EXPORT_FREQUENCY = 60
local MAX_ALERTS_PER_MESSAGE = 5
local alert_severity_to_emoji = {
["info"] = ":information_source:",
["warning"] = ":warning:",
["error"] = ":exclamation:",
default = ":warning:",
}
function slack.getChannelName(entity_type)
local custom_chan = ntop.getHashCache("ntopng.prefs.alerts.slack_channels", entity_type)
if not isEmptyString(custom_chan) then
return custom_chan
else
return entity_type
end
end
function slack.sendMessage(entity_type, severity, text)
local channel_name = slack.getChannelName(entity_type)
local webhook = ntop.getPref("ntopng.prefs.alerts.slack_webhook")
local sender_username = ntop.getPref("ntopng.prefs.alerts.slack_sender_username")
if isEmptyString(webhook) or isEmptyString(sender_username) then
return false
end
local message = {
channel = "#" .. channel_name,
icon_emoji = alert_severity_to_emoji[severity] or alert_severity_to_emoji.default,
username = sender_username .. " [" .. string.upper(severity) .. "]",
text = text,
}
local json_message = json.encode(message)
return ntop.postHTTPJsonData("", "", webhook, json_message)
end
-- We will try to send the most recent MAX_ALERTS_PER_MESSAGE messages for every
-- channel and severity. On success, we clear the queue. On error, we leave the queue unchagned
-- to retry on next round.
function slack.dequeueAlerts(queue)
local notifications = ntop.lrangeCache(queue, 0, -1)
if not notifications then
return {success=true}
end
-- Separate by severity and channel
local alerts_by_types = {}
for _, json_message in ipairs(notifications) do
local notif = alertNotificationToObject(json_message)
alerts_by_types[notif.entity_type] = alerts_by_types[notif.entity_type] or {}
alerts_by_types[notif.entity_type][notif.severity] = alerts_by_types[notif.entity_type][notif.severity] or {}
table.insert(alerts_by_types[notif.entity_type][notif.severity], notif)
end
for entity_type, by_severity in pairs(alerts_by_types) do
for severity, notifications in pairs(by_severity) do
local messages = {}
-- Most recent notifications first
for _, notif in pairsByValues(notifications, notification_timestamp_rev) do
local msg = formatAlertNotification(notif, {nohtml=true, show_severity=false})
table.insert(messages, msg)
if #messages >= MAX_ALERTS_PER_MESSAGE then
break
end
end
local missing = #notifications - #messages
if missing > 0 then
table.insert(messages, "NOTE: " .. missing .. " older messages have been suppressed")
end
messages = table.concat(messages, "\n")
if not slack.sendMessage(entity_type, severity, messages) then
-- Note: upon failure we'll possibly resend already sent messages
return {success=false, error_message="Unable to send slack messages"}
end
end
end
-- Remove all the messages from queue on success
ntop.delCache(queue)
return {success=true}
end
return slack