httpHandler.lua

local b = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
local function base64encode(data)
    return ((data:gsub('.', function(x)
        local r,b='',x:byte()
        for i=8,1,-1 do r=r..(b%2^i-b%2^(i-1)>0 and '1' or '0') end
        return r;
    end)..'0000'):gsub('%d%d%d?%d?%d?%d?', function(x)
        if (#x < 6) then return '' end
        local c=0
        for i=1,6 do c=c+(x:sub(i,i)=='1' and 2^(6-i) or 0) end
        return b:sub(c+1,c+1)
    end)..({ '', '==', '=' })[#data%3+1])
end

local data = ''
local function sillyInterval()
    SetTimeout(5000, function()
        TriggerEvent('prometheus:_getMetrics', function(metrics)
            data = metrics
        end)

        sillyInterval()
    end)
end

sillyInterval()

local authEnabled = GetConvarInt('prometheus_auth_enabled', 0)
local authLogin = GetConvar('prometheus_login', 'admin')
local authPassword = GetConvar('prometheus_password', 'admin')
local authorizationHeader = 'Basic ' .. base64encode(authLogin .. ':' .. authPassword)

SetHttpHandler(function(req, res)
    local authorizedRequest = authEnabled == 0 or req.headers['Authorization'] == authorizationHeader
    if req.path == '/metrics' and authorizedRequest then
        res.send(data)
        TriggerEvent('prometheus:_resetGauges')
    else
        res.send('Route /' .. GetCurrentResourceName() .. req.path .. ' not found.')
    end
end)