【进阶实战】基础设施即代码：环境配置的版本化管理封装

local repo = { current = 1 }
local function loadConfig(version)
    return readFromRepo(version)
end
local function applyConfig(cfg, machine)
    local applied = 0
    for k, v in pairs(cfg) do
        if readMachineConfig(machine, k) ~= v then
            writeMachineConfig(machine, k, v)
            applied = applied + 1
        end
    end
    return applied
end
local function deploy(machineName, version)
    local cfg = loadConfig(version)
    local changed = applyConfig(cfg, machineName)
    print(machineName .. " 应用 " .. changed .. " 项配置，版本 " .. version)
    return changed
end

local function detectDrift(machineName, version)
    local cfg = loadConfig(version)
    local drift = 0
    for k, v in pairs(cfg) do
        if readMachineConfig(machineName, k) ~= v then
            drift = drift + 1
        end
    end
    print(machineName .. " 配置漂移 " .. drift .. " 项")
    return drift
end