96 lines
2.6 KiB
Lua
96 lines
2.6 KiB
Lua
local socket = ngx.socket.tcp
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local cjson = require("cjson.safe")
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local assert = assert
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local new_tab = require "table.new"
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local clear_tab = require "table.clear"
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local clone_tab = require "table.clone"
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local nkeys = require "table.nkeys"
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-- if an Nginx worker processes more than (MAX_BATCH_SIZE/FLUSH_INTERVAL) RPS then it will start dropping metrics
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local MAX_BATCH_SIZE = 10000
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local FLUSH_INTERVAL = 1 -- second
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local metrics_batch = new_tab(MAX_BATCH_SIZE, 0)
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local _M = {}
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local function send(payload)
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local s = assert(socket())
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assert(s:connect("unix:/tmp/prometheus-nginx.socket"))
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assert(s:send(payload))
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assert(s:close())
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end
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local function metrics()
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return {
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host = ngx.var.host or "-",
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namespace = ngx.var.namespace or "-",
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ingress = ngx.var.ingress_name or "-",
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service = ngx.var.service_name or "-",
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path = ngx.var.location_path or "-",
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method = ngx.var.request_method or "-",
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status = ngx.var.status or "-",
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requestLength = tonumber(ngx.var.request_length) or -1,
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requestTime = tonumber(ngx.var.request_time) or -1,
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responseLength = tonumber(ngx.var.bytes_sent) or -1,
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upstreamLatency = tonumber(ngx.var.upstream_connect_time) or -1,
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upstreamResponseTime = tonumber(ngx.var.upstream_response_time) or -1,
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upstreamResponseLength = tonumber(ngx.var.upstream_response_length) or -1,
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--upstreamStatus = ngx.var.upstream_status or "-",
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}
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end
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local function flush(premature)
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if premature then
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return
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end
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if #metrics_batch == 0 then
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return
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end
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local current_metrics_batch = clone_tab(metrics_batch)
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clear_tab(metrics_batch)
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local payload, err = cjson.encode(current_metrics_batch)
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if not payload then
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ngx.log(ngx.ERR, "error while encoding metrics: ", err)
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return
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end
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send(payload)
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end
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local function set_metrics_max_batch_size(max_batch_size)
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if max_batch_size > 10000 then
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MAX_BATCH_SIZE = max_batch_size
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end
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end
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function _M.init_worker(max_batch_size)
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set_metrics_max_batch_size(max_batch_size)
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local _, err = ngx.timer.every(FLUSH_INTERVAL, flush)
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if err then
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ngx.log(ngx.ERR, string.format("error when setting up timer.every: %s", tostring(err)))
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end
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end
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function _M.call()
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local metrics_size = nkeys(metrics_batch)
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if metrics_size >= MAX_BATCH_SIZE then
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ngx.log(ngx.WARN, "omitting metrics for the request, current batch is full")
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return
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end
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metrics_batch[metrics_size + 1] = metrics()
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end
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if _TEST then
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_M.flush = flush
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_M.get_metrics_batch = function() return metrics_batch end
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_M.set_metrics_max_batch_size = set_metrics_max_batch_size
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end
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return _M
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