node.js - 使用带同步日志记录的 pino multistream

Question

据我了解，Pino (v 7.5.1) 默认执行同步日志记录。来自文档

In Pino's standard mode of operation log messages are directly written to the output stream as the messages are generated with a blocking operation.

我正在像这样使用 pino.multistreams

const pino = require('pino')
const pretty = require('pino-pretty')
const logdir = '/Users/punkish/Projects/z/logs'

const streams = [
    {stream: fs.createWriteStream(`${logdir}/info.log`, {flags: 'a'})},
    {stream: pretty()},
    {level: 'error', stream: fs.createWriteStream(`${logdir}/error.log`, {flags: 'a'})},
    {level: 'debug', stream: fs.createWriteStream(`${logdir}/debug.log`, {flags: 'a'})},
    {level: 'fatal', stream: fs.createWriteStream(`${logdir}/fatal.log`, {flags: 'a'})}
]

奇怪的是，Pino 的行为是异步的。我有一个 curl 操作乱序输出(在使用 log.info 的早期事件之前)

log.info('1')
.. code to do 1 something

log.info('2')
.. code to do 2 something

log.info('3')
.. code to do 3 something

const execSync = require('child_process').execSync
execSync(curl --silent --output ${local} '${remote}')

我的控制台输出是

1
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 39.5M  100 39.5M    0     0   108M      0 --:--:-- --:--:-- --:--:--  113M
2
3

这有点烦人和令人困惑。也许这不是 Pino 的错，也许是 curl 导致了问题。但是，如果我用 console.log 替换 pino logging，那么顺序就是预期的。所以问题似乎出在 Pino 的异步行为上。我怎样才能回到同步日志记录？

Answer 1

诀窍是调用 pino.destination({...}) 来创建 SonicBoom 输出流:fs.createWriteStream 的 pino 特定替代方案。 SonicBoom 选项有一个 bool 属性 sync。您还需要 pretty({...}) 中的 sync 选项。

const pino = require('pino')
const pretty = require('pino-pretty')
const logdir = '/Users/punkish/Projects/z/logs'

const createSonicBoom = (dest) => 
  pino.destination({dest: dest, append: true, sync: true})

const streams = [
    {stream: createSonicBoom(`${logdir}/info.log`)},
    {stream: pretty({
      colorize: true,
      sync: true,
    })},
    {level: 'error', stream: createSonicBoom(`${logdir}/error.log`)},
    {level: 'debug', stream: createSonicBoom(`${logdir}/debug.log`)},
    {level: 'fatal', stream: createSonicBoom(`${logdir}/fatal.log`)}
]

测试:

const log = pino({ level: 'info' }, pino.multistream(streams))

console.log('Before-Fatal')
log.fatal('Fatal')
log.error('Error')
log.warn('Warn')
console.log('After-Warn, Before-Info')
log.info('Info')
console.log('After-Info')

输出:

Before-Fatal[1234567890123] FATAL (1234567 on host): Fatal[1234567890127] ERROR (1234567 on host): Error[1234567890127] WARN (1234567 on host): WarnAfter-Warn, Before-Info[1234567890128] INFO (1234567 on host): InfoAfter-Info