[Question] Is it possible to define host resolution rules per browser instance?

In my daily work, I often have to tweak the /etc/hosts file for routing production site URLs to the development sites for testing. Is it possible to launch a browser instance with a set of customized host resolution rules? For example,

const browser = await chromium.launch( {
    hosts: {
        'example.com': '127.0.0.1',  // all the request to example.com will then be routed to my local machine.
    }
} );

I believe it’s possible by dockerizing my playwright testing program, but would like to see if there is a lightweight solution for this.

Thanks 😃

[PiotrCzapla]

Tried both variants, but still an issue with Chrome:

args: [
    // '--host-rules="MAP 127.0.0.1 dev.smthg'
    '--host-resolver-rules="MAP 127.0.0.1 dev.smthg'
]

I have Github Actions workflow and inside it I’m updating the etc/hosts file manually. Firefox is working fine, but looks like Chrome doesn’t see this file at all… The same happens locally with Windows 10

I think the code doesn’t work due to additional quote inside of the rule.

 args: [ '--host-resolver-rules="MAP 127.0.0.1 dev.smthg"' ]  // the double quote cause the issue

This argument should looks as follows in playwright:

args: [ '--host-resolver-rules=MAP 127.0.0.1 dev.smthg' ]

[philsch]

const browser = await chromium.launch({
  args: [ '--host-resolver-rules=MAP * 127.0.0.1' ]
});

Worked for me to direct all domains to be resolved by my local machine.

For example this loaded the content from my local running webserver:

const page = await browser.newPage();
const response = await page.goto('http://test.server.local/');
const text = await response.text();
expect(text).toContain('...')