ruby rest_client exception handling

Question

I'd like to do some HTTP REST requests in Ruby, using rest-client gem,

Following readme.md at https://github.com/rest-client/rest-client I wrote this simple command line script, trying to catch exceptions in case of response codes differents from 2xx:

RestClient.get('http://thisurldoesnotexist/resource') { |response, request, result, &block|
case response.code
  when 200
    p "It worked !"
    response
  else
    response.return!(request, result, &block)
  end
}

Hi got this on stdout output:

/home/*****/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/net/http.rb:878:in `initialize': getaddrinfo: Name or service not known (SocketError)
    from /home/solyaris/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/net/http.rb:878:in `open'
    from /home/solyaris/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/net/http.rb:878:in `block in connect'
    from /home/solyaris/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/timeout.rb:52:in `timeout'
    from /home/solyaris/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/net/http.rb:877:in `connect'
    from /home/solyaris/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/net/http.rb:862:in `do_start'
    from /home/solyaris/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/net/http.rb:851:in `start'
    from /home/solyaris/.rvm/gems/ruby-2.0.0-p247/gems/rest-client-1.6.7/lib/restclient/request.rb:172:in `transmit'
    from /home/solyaris/.rvm/gems/ruby-2.0.0-p247/gems/rest-client-1.6.7/lib/restclient/request.rb:64:in `execute'
    from /home/solyaris/.rvm/gems/ruby-2.0.0-p247/gems/rest-client-1.6.7/lib/restclient/request.rb:33:in `execute'
    from /home/solyaris/.rvm/gems/ruby-2.0.0-p247/gems/rest-client-1.6.7/lib/restclient.rb:68:in `get'
    from prova_rest.rb:3:in `<main>'

How can i catch SocketError ? where I'm wrong ?

thanks giorgio

Answer 1

The callback block is executed only when receiving some response from the server. In this case, the name resolving is failed so RestClient.get just throws an exception without entering the block. Thus just wrap your code within a begin...end construct.

begin
  RestClient.get('http://thisurldoesnotexist/resource') { |response, request, result, &block|
  case response.code
    when 200
      p "It worked !"
      response
    else
      response.return!(request, result, &block)
    end
  }
rescue SocketError => e
  # Handle your error here
end