Chef : Notify resource from ruby_block

Lets say for some sane/insane reason , you want to notify a resource to take some action from within ruby_block , you can accomplish it as follows

ruby_block "dummy" do
    block do
        if some_condition_is_true
           resources(:file => "create_file").run_action(:create)
        end
    end
end

file "create_file" do
         path "/tmp/test.txt"
         owner "you"
         content "dummy"
         action :nothing
end

Caveat :

       If file resource "create_file" further notifies another resource , that resource will not be notified. What i mean to say is that calling a resource from within ruby_block by using run_action method directly does not build up the notification chain . For example if file resource was as below

file "create_file" do
         path "/tmp/test.txt"
         owner "you"
         content "dummy"
         action :nothing
         notifies :run , resources(:execute => "some_script")
end

and file resource is notified from within ruby_block , then file resource will not further notify "some_script" resource.

Game Of Life

Just finished Basic "Game Of life" simulation on HTML5 canvas. Here is the demo and here is the source code

I used kineticjs library to interact with canvas.

Thanks "this site" for button.

Nodejs Express : request.body is null

Just had an other frustration with nodejs and this time again problem with header and fault was mine since i missed Content-type header.
While writing a nodeunit test ,

exports.parseRequest = function(test){
 http = require('http')
 test.expect(1)
 options = {
  "host": "127.0.0.1",
  "port": 3000,
  "path": "/movies/",
  "method": 'POST',
  "headers" : {
   Content-Type":"application/x-www-form-urlencoded"
  }
 }  
 request = http.request(options,function(response){
  console.log("Status "+response.statusCode)
  result = ''
  response.on('data',function(chunk){
   result += chunk
  })
  response.on('end',function(){
   response.destroy() 
   test.equal(result,"Hello World", "Reponse got")
   test.done();
   
  })
 })
 request.on('error' , function (connectionException){
   console.log("ERROR occured while creating connection to localhost "+connectionException);
 })
 request.write("data=sheat");
 request.end();
}

and there you go , i missed that content-type header on line 10 above and ended up wasting 30+mins to figure out why request.body is 'undefined'. >Make the header adjust according to content , application/json etc

Nodejs : not sending host header by default

After having heard about nodejs for so long now , i decided to play with it today and unfortunately ended up in frustation when i was not able to make the below <20 lines code execute successfully.

var connection = http.createClient(80, "localhost");


var request = connection.request('GET', "/");

request.end();


request.on('response', function(response){
 
  var result = "";
  console.log(response.statusCode)
  response.on('data', function(chunk){
   result += chunk;
  })
  response.on('end', function(){
   console.log(result);
  })
  
});
 
connection.addListener('error' , function (connectionException){
 console.log("ERROR occured while calling Rotten Tomatoes Api "+connectionException);
})

I was initially making call to rottentomatoes api and was getting 400 , Bad request.
I changed hostname to localhost ( i had apache running locally) and was more frustated to see the same 400. This prompted me to check the apache error_log and this is what i was getting there

client sent HTTP/1.1 request without hostname (see RFC2616 section 14.23):

and little googling told me that nodejs does not send the host header by default [Stumped]. so i had to manually add the host header like below.

var request = connection.request('GET', "/" , {"Host":"localhost");

I am not sure but i think it should be a good idea to include some common headers by default in the request sent by nodejs.