http server respond with inappropriate default headers for HEAD method

[abbshr]

• Version: >= 10.x
• Platform: any
• Subsystem: http

To implement a HTTP keep alive mechanism, I use the http.Agent({ keepAlive: true }) and http.request({ agent, method, host, port }).

Everything is ok when the method is GET or TRACE and others, the agent reuse the TCP connection as I expect.

But when changing the method to HEAD, the agent close the connection when server responded.

From the response header, the only different is that: for HEAD method, there isn't a Content-Length: 0 or Transfer-Encoding: chunked in the default header (but GET has by default), so the HTTP parser think this connection should not be kept alive.

But from the RFC, we can infer that if keep-alive was enabled, either Content-Length: 0 or Transfer-Encoding: chunked should be setted in response header, I think this should be a default behavior.

# server
const http = require("http")

const server = http.createServer((req, res) => {
  // res.setHeader("Content-Length", 0)
  // res.setHeader("Transfer-Encoding", "chunked")
  res.end()
})

server.keepAliveTimeout = 0
server.listen(2333, "x.x.x.x")

# client
const http = require("http")

const agent = new http.Agent({
  keepAlive: true,
})

request = () => {
  const req = http.request({
    agent,
    host: "x.x.x.x",
    port: 2333,
    method: 'HEAD',
  })

  req.end()
}

request()

[jimmiehansson]

Hey @abbshr
In contrary to GET this is the intended behavior for the HEAD requests as its simply a meta request of GET, excluding the body contents that you would typically have in GET, this seems like an expected behavior from the http server as there is no buffer or chunk to expect.
RFC-accordingly, depending on the request payload this may also lead to early termination.
Did i understand your problem correctly?
Also see the semantics of the HTTP payload https://tools.ietf.org/html/rfc7231#section-3.3

[wa-Nadoo]

It seems this issue should be reopened because the bugfix commit was reverted.

[nawed2611]

Hey! Can I work on this?