Adding upstream version 2.9.5.upstream/2.9.5

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 426 insertions, 0 deletions

diff --git a/examples/lua/mailers.lua b/examples/lua/mailers.lua
new file mode 100644
index 0000000..47a8356
--- /dev/null
+++ b/examples/lua/mailers.lua
@@ -0,0 +1,426 @@
+-- haproxy mailers implementation in lua
+--
+-- Provides a pure lua alternative to tcpcheck mailers.
+--
+-- To be loaded using "lua-load" from haproxy configuration to handle
+-- email-alerts directly from lua and disable legacy tcpcheck implementation.
+
+local SYSLOG_LEVEL = {
+	["EMERG"] = 0,
+	["ALERT"] = 1,
+	["CRIT"] = 2,
+	["ERROR"] = 3,
+	["WARN"] = 4,
+	["NOTICE"] = 5,
+	["INFO"] = 6,
+	["DEBUG"] = 7
+}
+
+local mailqueue = core.queue()
+
+-- smtp : send SMTP message
+--
+-- Copyright 2018 Thierry Fournier
+--
+-- This function is compliant with HAProxy cosockets
+-- EHLO was replaced with HELO for better compatibility with
+-- basic mail server implementations
+--
+-- <server> should contain the full server address (including port) in the
+-- same format used in haproxy config file. It will be passed as it is to
+-- tcp::connect() without explicit port argument. See Socket.connect()
+-- manual for more information.
+--
+-- The function will abort after <timeout> ms
+function smtp_send_email(server, timeout, domain, from, to, data)
+        local ret
+        local reason
+        local tcp = core.tcp()
+        local smtp_wait_code = function(tcp, code)
+                local ret
+                -- Read headers until we reac a 2.. code.
+                while true do
+                        -- read line
+                        ret = tcp:receive("*l")
+                        if ret == nil then
+                                return false, "Connection unexpectedly closed"
+                        end
+                        -- expected code
+                        if string.match(ret, code) ~= nil then
+                                return true, nil
+                        end
+                        -- other code
+                        if string.match(ret, '^%d%d%d ') ~= nil then
+                                return false, ret
+                        end
+                        -- other informational message, wait.
+                end
+        end
+
+	if timeout ~= nil and timeout > 0 then
+		tcp:settimeout(timeout / 1000)
+	end
+
+        if tcp:connect(server) == nil then
+                return false, "Can't connect to \""..server.."\""
+        end
+
+        ret, reason = smtp_wait_code(tcp, '^220 ')
+        if ret == false then
+                tcp:close()
+                return false, reason
+        end
+
+        if tcp:send("HELO " .. domain .. "\r\n") == nil then
+                tcp:close()
+                return false, "Connection unexpectedly closed"
+        end
+
+        ret, reason = smtp_wait_code(tcp, '^250 ')
+        if ret == false then
+                tcp:close()
+                return false, reason
+        end
+
+        if tcp:send("MAIL FROM: <" .. from .. ">\r\n") == nil then
+                tcp:close()
+                return false, "Connection unexpectedly closed"
+        end
+
+        ret, reason = smtp_wait_code(tcp, '^250 ')
+        if ret == false then
+                tcp:close()
+                return false, reason
+        end
+
+        if tcp:send("RCPT TO: <" .. to .. ">\r\n") == nil then
+                tcp:close()
+                return false, "Connection unexpectedly closed"
+        end
+
+        ret, reason = smtp_wait_code(tcp, '^250 ')
+        if ret == false then
+                tcp:close()
+                return false, reason
+        end
+
+        if tcp:send("DATA\r\n") == nil then
+                tcp:close()
+                return false, "Connection unexpectedly closed"
+        end
+
+        ret, reason = smtp_wait_code(tcp, '^354 ')
+        if ret == false then
+                tcp:close()
+                return false, reason
+        end
+
+        if tcp:send(data .. "\r\n.\r\n") == nil then
+                tcp:close()
+                return false, "Connection unexpectedly closed"
+        end
+
+        ret, reason = smtp_wait_code(tcp, '^250 ')
+        if ret == false then
+                tcp:close()
+                return false, reason
+        end
+
+        if tcp:send("QUIT\r\n") == nil then
+                tcp:close()
+                return false, "Connection unexpectedly closed"
+        end
+
+        ret, reason = smtp_wait_code(tcp, '^221 ')
+        if ret == false then
+                tcp:close()
+                return false, reason
+        end
+
+        tcp:close()
+        return true, nil
+end
+
+local function send_email_alert(srv, level, message, when)
+	local mailers = srv:get_proxy():get_mailers()
+
+	if mailers == nil then
+		return -- nothing to do
+	end
+
+	if level > mailers.log_level then
+		return
+	end
+
+	-- email sending is performed asynchronously thanks to mailqueue
+	local job = {}
+
+	job.mailconf = mailers
+	job.when = when
+	job.msg = message
+
+	-- enqueue email job
+	mailqueue:push(job)
+
+end
+
+local function srv_get_check_details(check)
+	local c = core.concat()
+
+	c:add(", ")
+	c:add(string.format("reason: %s", check.reason.desc))
+	if check.reason.code ~= nil
+	then
+		c:add(string.format(", code: %d", check.reason.code))
+	end
+	if check.duration >= 0
+	then
+		c:add(string.format(", check duration: %dms", check.duration))
+	end
+
+	return c:dump()
+end
+
+local function srv_get_status_details(srv, requeued)
+	local c = core.concat()
+
+	c:add(string.format("%d active and %d backup servers left.",
+			    srv:get_proxy():get_srv_act(),
+			    srv:get_proxy():get_srv_bck()))
+	c:add(" ")
+	c:add(string.format("%d sessions active, %d requeued, %d remaining in queue",
+			    srv:get_cur_sess(),
+			    requeued,
+			    srv:get_pend_conn()))
+	return c:dump()
+end
+
+local function srv_state_handler(event, data, when)
+	local server = data.reference
+	local state = data.state
+	local c = core.concat()
+	local log_level = SYSLOG_LEVEL["ALERT"]
+	local message
+
+	if server == nil then
+		-- server already removed, can't do much
+		return
+	end
+
+	if state.admin then
+		-- don't report if is related to an administrative change and not
+		-- directly due to an operational change
+		return
+	end
+
+	-- we don't send an alert if the server was previously stopping
+	if state.old_state == "STOPPING" or server:is_draining() then
+		log_level = SYSLOG_LEVEL["NOTICE"]
+	end
+
+	-- prepare the message
+	c:add(string.format("Server %s/%s is %s",
+			    server:get_proxy():get_name(),
+			    server:get_name(),
+			    state.new_state == "RUNNING" and "UP" or "DOWN"))
+
+	if server:tracking()
+	then
+		-- server is tracking another server, it means that the operational
+		-- state change is inherited
+		c:add(string.format(" via %s/%s",
+				    server:tracking():get_proxy():get_name(),
+				    server:tracking():get_name()))
+	end
+
+	if state.check ~= nil
+	then
+		c:add(srv_get_check_details(state.check))
+	else
+		c:add(state.cause)
+	end
+
+	c:add(". ")
+	c:add(srv_get_status_details(server, state.requeued))
+	send_email_alert(server, log_level, c:dump(), when)
+end
+
+local function srv_admin_handler(event, data, when)
+	local server = data.reference
+	local admin = data.admin
+	local c = core.concat()
+
+	if server == nil then
+		-- server already removed, can't do much
+		return
+	end
+
+	-- only send an email when server is entering drain state and not under maint
+	if not (not admin.old_admin["DRAIN"] and
+		admin.new_admin["DRAIN"] and
+		not admin.new_admin["MAINT"]) then
+		return
+	end
+
+	-- prepare the message
+	c:add(string.format("Server %s/%s enters drain state",
+			    server:get_proxy():get_name(),
+			    server:get_name()))
+
+	if server:tracking() and admin.new_admin["IDRAIN"]
+	then
+		-- server is tracking another server and IDRAIN is set, it means
+		-- that the admin state change is inherited
+		c:add(string.format(" via %s/%s",
+				    server:tracking():get_proxy():get_name(),
+				    server:tracking():get_name()))
+	end
+
+	c:add(". ")
+	c:add(srv_get_status_details(server, admin.requeued))
+	send_email_alert(server, SYSLOG_LEVEL["NOTICE"], c:dump(), when)
+end
+
+local function srv_check_handler(event, data, when)
+	local server = data.reference
+	local check = data.check
+	local c = core.concat()
+
+	if server == nil then
+		-- server already removed, can't do much
+		return
+	end
+
+	-- we will always send an email, prepare the message
+	c:add(string.format("%s check for %sserver %s/%s ",
+			    check.agent and "Agent" or "Health",
+			    server:is_backup() and "backup " or "",
+			    server:get_proxy():get_name(),
+			    server:get_name()))
+
+	if check.result == "CONDPASS" then
+		c:add("conditionally succeeded")
+	elseif check.result == "PASSED" then
+		c:add("succeeded")
+	else
+		c:add("failed")
+	end
+
+	c:add(srv_get_check_details(check))
+
+	c:add(", status: ")
+	if check.health.cur >= check.health.rise then
+		-- good
+		c:add(string.format("%d/%d %s",
+				    check.health.cur - check.health.rise + 1,
+				    check.health.fall,
+				    server:get_weight() and "UP" or "DRAIN"))
+	else
+		-- bad
+		c:add(string.format("%d/%d DOWN",
+				    check.health.cur,
+				    check.health.rise))
+	end
+
+	send_email_alert(server, SYSLOG_LEVEL["INFO"], c:dump(), when)
+end
+
+-- single function for multiple event types since all events come
+-- from the same subscription to reduce memory footprint
+local function srv_event_dispatch(event, data, mgmt, when)
+	if event == "SERVER_STATE" then srv_state_handler(event, data, when) end
+	if event == "SERVER_ADMIN" then srv_admin_handler(event, data, when) end
+	if event == "SERVER_CHECK" then srv_check_handler(event, data, when) end
+end
+
+local function mailers_track_server_events(srv)
+	local mailer_conf = srv:get_proxy():get_mailers()
+
+	-- don't track server events if the parent proxy did not enable email alerts
+	if mailer_conf == nil
+	then return
+	end
+
+	-- email alerts are enabled, track server state and admin changes
+	local subscriptions = {"SERVER_STATE", "SERVER_ADMIN"}
+
+	if mailer_conf.track_server_health
+	then
+		-- track server check events as well (this event source is expensive)
+		table.insert(subscriptions, "SERVER_CHECK")
+	end
+
+	-- perform the event subscription from the server
+	srv:event_sub(subscriptions, srv_event_dispatch)
+end
+
+local function srv_event_add(event, data)
+	-- do nothing if the server was already removed
+	if data.reference == nil
+	then return
+	end
+
+	-- server still exists, check if it can be tracked for email alerts
+	mailers_track_server_events(data.reference)
+end
+
+
+-- disable legacy email-alerts since email-alerts will be sent from lua directly
+core.disable_legacy_mailers()
+
+-- event subscriptions are purposely performed in an init function to prevent
+-- email alerts from being generated too early (when process is starting up)
+core.register_init(function()
+
+	-- do nothing if not on primary thread
+	-- this prevents emails from being sent multiple times when
+	-- lua-load-per-thread is used to load the script since the task
+	-- will be started on each haproxy thread
+	if core.thread > 1 then core.done() end
+
+	-- subscribe to SERVER_ADD to be notified when new servers are added
+	core.event_sub({"SERVER_ADD"}, srv_event_add)
+
+	-- loop through existing backends to detect existing servers
+	for backend_name, backend in pairs(core.backends) do
+		for srv_name, srv in pairs(backend.servers) do
+			mailers_track_server_events(srv)
+		end
+	end
+
+end)
+
+-- mail queue
+core.register_task(function()
+	while true
+	do
+		local job = mailqueue:pop_wait()
+
+		if job ~= nil then
+			local date = os.date("%a, %d %b %Y %T %z (%Z)", job.when)
+			local c = core.concat()
+
+			-- prepare email body
+			c:add(string.format("From: %s\r\n", job.mailconf.smtp_from))
+			c:add(string.format("To: %s\r\n", job.mailconf.smtp_to))
+			c:add(string.format("Date: %s\r\n", date))
+			c:add(string.format("Subject: [HAProxy Alert] %s\r\n", job.msg))
+			c:add("\r\n")
+			c:add(string.format("%s\r\n", job.msg))
+
+			-- send email to all mailservers
+			for name, mailsrv in pairs(job.mailconf.mailservers) do
+				-- finally, send email to server
+				local ret, reason = smtp_send_email(mailsrv,
+								    job.mailconf.mailservers_timeout,
+								    job.mailconf.smtp_hostname,
+								    job.mailconf.smtp_from,
+								    job.mailconf.smtp_to,
+								    c:dump())
+				if ret == false then
+					core.Warning("Can't send email alert to ".. name .. ": " .. reason)
+				end
+			end
+		end
+	end
+end)