Vite startup 3000 port occupancy problem

[Brolly0204]

Describe the bug

My computer has started a front-end project, and the listening port is 3000. When I start another vite project, it still occupies port 3000 and does not open other ports for me. As a result, when I access the 3000 port link, I access the vite project, but the previous project can't be accessed.

Reproduction

https:/Brolly0204/vite-admin

System Info

macOS Monterey  version 12.2.1
vite: "^2.8.0"

Used Package Manager

pnpm

Logs

vite --host

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https:/vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[bluwy]

When starting another Vite project, Vite should technically detect that 3000 is occupied and try 3001 though 🤔 That's the behaviour I get currently with macOS Monterey v12.2.1 as well.

[Brolly0204]

When starting another Vite project, Vite should technically detect that 3000 is occupied and try 3001 though 🤔 That's the behaviour I get currently with macOS Monterey v12.2.1 as well.

I tried and found the reason. When two projects are started, one specifies -- host and the other does not specify -- host will look like this.

[Brolly0204]

When starting another Vite project, Vite should technically detect that 3000 is occupied and try 3001 though 🤔 That's the behaviour I get currently with macOS Monterey v12.2.1 as well.

[Brolly0204]

When starting another Vite project, Vite should technically detect that 3000 is occupied and try 3001 though 🤔 That's the behaviour I get currently with macOS Monterey v12.2.1 as well.

I used the same port service as the vite project to build the service with node, which caused a strange phenomenon.

vite

npm run dev -- --host

node server
localhost:3000

import { createServer } from 'http'

const httpServer = createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'application/json' });
  res.end(JSON.stringify({
    data: 'Hello World!'
  }));
})

// const host = '192.168.1.101'
const host = 'localhost'
const strictPort = false
const port = 3000
const server = function () {
  return new Promise((resolve, reject) => {
    const onError = (e: Error & { code?: string }) => {
      console.log('e', e)
      if (e.code === 'EADDRINUSE') {
        if (strictPort) {
          httpServer.removeListener('error', onError)
          reject(new Error(`Port ${port} is already in use`))
        } else {
          console.info(`Port ${port} is in use, trying another one...`)
          httpServer.listen(++port, host)
        }
      } else {
        httpServer.removeListener('error', onError)
        reject(e)
      }
    }
    httpServer.on('error', onError)
    httpServer.listen(port, host, () => {
      console.log('listening to', port)
      httpServer.removeListener('error', onError)
      resolve(port)
    })
  })
}
server()

[haoqunjiang]

Seems a duplicate of #5241 (comment)