net/http PUT with body causes problems - ruby

Question

I want to use the Cloudera API from ruby. Therefore I want to
update the configuration of the cloudera manager, which is done
with an HTTP PUT request containing some json data.
The URL is http://localhost:7180/api/v11/cm/config, my first approach was the following code:
require 'net/http'
require 'base64'
port = 7180
host = 'localhost'
req = Net::HTTP::Put.new('/api/v11/cm/config')
req.body = '{"items":[{"name":"TSQUERY_STREAMS_LIMIT","value":1000},{"name":"parcel_proxy_server","value":"proxy"},{"name":"parcel_proxy_port","value":"8080"},{"name":"parcel_update_freq","value":"1"}]}'
req['Content-Type'] = 'application/json'
req['Authorization'] = "Basic #{Base64.encode64('admin:admin')}"
client = Net::HTTP.new(host, port)
resp = client.request(req)
puts resp
puts resp.to_hash
puts resp.body
This variant returns a 400 Bad Request response with the message
"message" : "No content to map due to end-of-input\n at [Source: org.apache.cxf.transport.http.AbstractHTTPDestination$1#4561cbc9; line: 1, column: 1]"
If I want to trace this in wireshark with the setting tcp.port == 7180, this request does somehow not show up.
Then I switched to using Net::HTTP.start with the following source code:
require 'net/http'
require 'base64'
port = 7180
host = 'localhost'
req = Net::HTTP::Put.new('/api/v11/cm/config')
req.body = '{"items":[{"name":"TSQUERY_STREAMS_LIMIT","value":1000},{"name":"parcel_proxy_server","value":"proxy"},{"name":"parcel_proxy_port","value":"8080"},{"name":"parcel_update_freq","value":"1"}]}'
req['Content-Type'] = 'application/json'
req['Authorization'] = "Basic #{Base64.encode64('admin:admin')}"
resp = Net::HTTP.start(host, port) { |client| client.request(req) }
puts resp
puts resp.to_hash
puts resp.body
This thing also returned a bad request, but without any body or else. In contrast to the first approach, this one showed up in wireshark but the body it posted was depicted as with Hypertext-Transfer-Protocol. If I do the same request with cURL, the request body is correctly shown as JavaScript Object Notation.
Does anybody know what the problem of my requests is?

Answer 1

Ok so I tried around for several hours but this behavior is rather strange:
To resolve this I first used Net::HTTP.start instead of Net::HTTP.new. Second and even more important:
I used to do basic authentication by setting the header value manually as you could see in
req['Authorization'] = "Basic #{Base64.encode64('admin:admin')}"
But Net::HTTP::Put already provides a basic_auth method. If this one is not used, strange errors as the ones that I got will occur.
So the working version looks like this:
req = Net::HTTP::Put.new('/api/v11/cm/config')
req.body = '{"items":[{"name":"TSQUERY_STREAMS_LIMIT","value":1000},{"name":"parcel_proxy_server","value":"proxy"},{"name":"parcel_proxy_port","value":"8080"},{"name":"parcel_update_freq","value":"1"}]}'
req['Content-Type'] = 'application/json'
req.basic_auth 'admin', 'admin'
resp = Net::HTTP.start(host, port) { |client| client.request(req) }