129 lines
3.0 KiB
Lua
Executable File
129 lines
3.0 KiB
Lua
Executable File
#!/usr/bin/lua
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-- Metrics web server
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-- Copyright (c) 2016 Jeff Schornick <jeff@schornick.org>
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-- Copyright (c) 2015 Kevin Lyda <kevin@lyda.ie>
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-- Licensed under the Apache License, Version 2.0
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socket = require("socket")
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-- get configs
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local omit_zero_values = os.getenv("OMIT_ZERO_VALUES") == "1"
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-- Parsing
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function space_split(s)
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local elements = {}
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for element in s:gmatch("%S+") do
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table.insert(elements, element)
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end
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return elements
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end
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function get_contents(filename)
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local f = io.open(filename, "rb")
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local contents = ""
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if f then
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contents = f:read("*a")
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f:close()
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end
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return contents
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end
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-- Metric printing
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function print_metric(metric, labels, value)
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local label_string = ""
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if labels then
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for label, value in pairs(labels) do
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label_string = label_string .. label .. '="' .. value .. '",'
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end
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label_string = "{" .. string.sub(label_string, 1, -2) .. "}"
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end
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output(string.format("%s%s %s", metric, label_string, value))
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end
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function metric(name, mtype, labels, value)
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output("# TYPE " .. name .. " " .. mtype)
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local outputter = function(labels, value)
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if not (omit_zero_values and tonumber(value) == 0) then
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print_metric(name, labels, value)
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end
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end
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if value then
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outputter(labels, value)
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end
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return outputter
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end
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function timed_scrape(collector)
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local start_time = socket.gettime()
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local success = 1
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local status, err = pcall(collector.scrape)
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if not status then
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success = 0
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io.stderr:write(err)
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end
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return (socket.gettime() - start_time), success
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end
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function run_all_collectors(collectors)
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local metric_duration = metric("node_scrape_collector_duration_seconds", "gauge")
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local metric_success = metric("node_scrape_collector_success", "gauge")
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for _, cname in pairs(collectors) do
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if col_mods[cname] ~= nil then
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local duration, success = timed_scrape(col_mods[cname])
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local labels = { collector = cname }
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metric_duration(labels, duration)
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metric_success(labels, success)
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end
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end
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end
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-- Web server-specific functions
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function handle_request(env)
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if env.PATH_INFO ~= "/metrics" then
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uhttpd.send("Status: 404 Not Found\r\n")
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uhttpd.send("Server: lua-metrics\r\n")
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uhttpd.send("Content-Type: text/plain\r\n\r\n")
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uhttpd.send("ERROR: File Not Found.")
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else
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uhttpd.send("Status: 200 OK\r\n")
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uhttpd.send("Server: lua-metrics\r\n")
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uhttpd.send("Content-Type: text/plain; version=0.0.4\r\n\r\n")
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local cols = {}
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for c in env.QUERY_STRING:gmatch("collect[^=]*=([^&]+)") do
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cols[#cols + 1] = c
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end
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if #cols == 0 then
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cols = col_names
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end
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run_all_collectors(cols)
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end
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end
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-- Main program
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col_mods = {}
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col_names = {}
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ls_fd = io.popen("ls -1 /usr/lib/lua/prometheus-collectors/*.lua")
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for c in ls_fd:lines() do
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c = c:match("([^/]+)%.lua$")
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col_mods[c] = require("prometheus-collectors." .. c)
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col_names[#col_names + 1] = c
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end
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ls_fd:close()
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output = function(str)
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uhttpd.send(str .. "\n")
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end
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if arg ~= nil then
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output = print
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run_all_collectors(col_names)
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end
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