DNR & Proxy

[erosman]

The application of declarativeNetRequest on proxies does not appear to have been discussed.

As an example, it can be useful for passing user/pass via headers, as an (easier!?) alternative to webRequest.onAuthRequired.
Note: It might require a special flag/property in DNR to separate it from other requests.

Scenario: Browser -> proxyurl.com -> target.com

It appears that the urlFilter refers to the target.com.

const removeRuleIds = [1];
const addRules = [
  {
    id: 1,
    priority: 1,
    action: {
      type: 'modifyHeaders',
      responseHeaders: [
        {
          header: 'header-1',
          operation: 'set',
          value: 'header1-added'
        }
      ]
    },
    condition: {urlFilter: '||proxyurl.com' }
  }
];

chrome.declarativeNetRequest.updateDynamicRules({removeRuleIds, addRules});

See Also:
Issue 1318138: Add headers using declarativeNetRequest only if the request is being proxied

[Rob--W]

webRequest.onAuthRequired continues to be supported in MV3 (at least in Chrome and Firefox). What would be the value of this functionality in DNR?

[erosman]

Passing user/pass was only an example. There might!? be occasions where DNR control might be needed for the proxy URL e.g. stripping some headers, or adding cookies, etc.