How to log all headers in nginx?

Question

How do I log all the headers the client (browser) has sent in Nginx? I also want to log the response headers. Note that I am using nginx as reverse proxy.

After goi

Answer 1

Based on @user1778602 response the set_by_lua can be used to set all headers into a variable to be consumed later at the log_format. The following sets all headers in the variable "$request_headers"

set_by_lua $request_headers '
  local h = ngx.req.get_headers()
  local request_headers_all = ""
  for k, v in pairs(h) do
    request_headers_all = request_headers_all .. ""..k..": "..v..";"
  end
  return request_headers_all
';

Answer 2

After much research, I can conclude that it is not possible out of the box.

Update- you can use openresty which comes with Lua. Using Lua one can do pretty cool things, including logging all of the headers to say, Redis or some other server

Answer 3

As @gauravphoenix said you need opnresty which comes with Lua. See https://github.com/openresty/lua-nginx-module/ for installing it. Once it's running then add in nginx

header_filter_by_lua_block {
  local h = ngx.req.get_headers()
  for k, v in pairs(h) do
    ngx.log(ngx.ERR, "Got header "..k..": "..v..";")
  end
}

Inspect your error log.