Tracking issue: HTTP_PROXY/HTTPS_PROXY/NO_PROXY support in Node.js

• Support https/http proxies via HTTP_PROXY/HTTPS_PROXY/NO_PROXY in fetch() (behind NODE_USE_ENV_PROXY)
  • Initial support https://github.com/nodejs/node/pull/57165
  • align with curl: do not tunnel for http proxy https://github.com/nodejs/undici/issues/4083
  • align with curl: support keep-alive https://github.com/nodejs/undici/issues/4086
• Support https/http proxies via HTTP_PROXY/HTTPS_PROXY/NO_PROXY in http(s) builtins (behind NODE_USE_ENV_PROXY)
  • Initial support for http(s).request and agent: https://github.com/nodejs/node/pull/58980
  • Check that it allows other popular user-land agents (for proxy or not) to operate with/without NODE_USE_ENV_PROXY (investigation)
  • Check that it works transparently with popular npm packages that uses http/https.request (investigation)
• Investigate enabling NODE_USE_ENV_PROXY by default
  • In fetch() (less risky since fetch is patched less in the wild)
  • In http(s) builtins (might be too risky, need to investigate)
• Share code between the fetch and the http(s) builtin implementation (e.g. env var parsing & matching)
• Add a CLI flag that allows enabling proxies: https://github.com/nodejs/node/issues/59100
• Bug fixes: https://github.com/nodejs/node/issues/62054

Some nice to haves (depend on whether there are volunteers that want to pick them up):

• Socks 5 proxy support
  • Socks5 proxy support in undici: https://github.com/nodejs/undici/issues/2224
  • Socks5 proxy support in http/https builtins
• HTTP2 support? https://github.com/nodejs/node/issues/57872#issuecomment-3209437143
  • Support it properly in the http2.connect
  • Until then, make sure fetch() doesn't advertise h2 when proxy is enabled?

Old issues: https://github.com/nodejs/node/issues/8381 https://github.com/nodejs/node/issues/15620