Sample server & client for Rack hijack proxy questions - ruby

Question

I've got sample app for hijack proxy server
io_lambda = lambda{ |io|
3.times do |i|
puts i
io.write "David\r\n"
end
io.close
}
run lambda{ |req|
[
200,
[ [ "rack.hijack", io_lambda ] ],
[""]
]
}
and starting it
rackup config.ru -p 3000
Now I trying to code client for it. First, just curl it:
curl http://localhost:3000 -vv
and get following client output:
* Rebuilt URL to: http://localhost:3000/
* Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 3000 (#0)
> GET / HTTP/1.1
> Host: localhost:3000
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 200 OK
< Transfer-Encoding: chunked
<
David
David
* transfer closed with outstanding read data remaining
* stopped the pause stream!
* Closing connection 0
curl: (18) transfer closed with outstanding read data remaining
now, with httparty:
require 'rubygems'
require 'bundler/setup'
Bundler.require(:default)
response = HTTParty.get('http://localhost:3000')
puts response.body, response.code, response.message, response.headers.inspect
I get:
→ ruby httparty-client.rb
Traceback (most recent call last):
19: from httparty-client.rb:5:in `<main>'
18: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/httparty-0.17.1/lib/httparty.rb:627:in `get'
17: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/httparty-0.17.1/lib/httparty.rb:508:in `get'
16: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/httparty-0.17.1/lib/httparty.rb:594:in `perform_request'
15: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/gems/2.6.0/gems/httparty-0.17.1/lib/httparty/request.rb:145:in `perform'
14: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http.rb:1470:in `request'
13: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http.rb:920:in `start'
12: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http.rb:1472:in `block in request'
11: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http.rb:1479:in `request'
10: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http.rb:1517:in `transport_request'
9: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:166:in `reading_body'
8: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:229:in `body'
7: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:204:in `read_body'
6: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:283:in `read_body_0'
5: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:278:in `inflater'
4: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:285:in `block in read_body_0'
3: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:324:in `read_chunked'
2: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:324:in `ensure in read_chunked'
1: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/protocol.rb:159:in `read'
/Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/protocol.rb:225:in `rbuf_fill': end of file reached (EOFError)
last try with net/http:
require 'net/http'
streamURL = 'http://localhost:3000'
uri = URI.parse(streamURL)
Net::HTTP.start(uri.host, uri.port) do |http|
request = Net::HTTP::Get.new uri.request_uri
http.request request do |response|
response.read_body do |chunk|
#We get the data here chunk-by-chunk
puts chunk
end
end
end
I get:
→ ruby net-http-client.rb
David
David
David
David
Traceback (most recent call last):
16: from net-http-client.rb:7:in `<main>'
15: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http.rb:605:in `start'
14: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http.rb:920:in `start'
13: from net-http-client.rb:10:in `block in <main>'
12: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http.rb:1479:in `request'
11: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http.rb:1517:in `transport_request'
10: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:165:in `reading_body'
9: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http.rb:1518:in `block in transport_request'
8: from net-http-client.rb:11:in `block (2 levels) in <main>'
7: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:204:in `read_body'
6: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:283:in `read_body_0'
5: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:278:in `inflater'
4: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:285:in `block in read_body_0'
3: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:324:in `read_chunked'
2: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/http/response.rb:324:in `ensure in read_chunked'
1: from /Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/protocol.rb:159:in `read'
/Users/khataev/.rbenv/versions/2.6.1/lib/ruby/2.6.0/net/protocol.rb:225:in `rbuf_fill': end of file reached (EOFError)
Could someone explain me:
1) Why curl return David x2, httparty - nothing and net/http - David x4, while server sent 5? Also I'm curious why httparty and net/http results differ, because one uses another under the hood.
2) Why in all cases we have an error (transfer closed with outstanding read data remaining and end of file reached (EOFError))?

Answer 1

Have figured it out. Headers do matter. This version makes it work for all clients
io_lambda = lambda{ |io|
5.times do |i|
puts i
io.write "David\r\n"
sleep 1
end
io.close
}
app = lambda do |env|
response_headers = {}
response_headers['Transfer-Encoding'] = 'binary'
response_headers["Content-Type"] = "text/plain"
response_headers["rack.hijack"] = io_lambda
[200, response_headers, nil]
end
run app