Debug Blitline Callback on Localhost

  Set up a Sinatra Callback Listener

First we'll create a trivial sinatra listner to listen for the Blitline callback:

gem install sinatra

Then we'll make the listener:

sudo nano blitline_listener.rb

Paste the following into the file:

require 'sinatra'

post '/callback' do
  puts "RESULTS->" + params.inspect
end

Hit ctrl-O and Y and Enter to save

Now start the ruby server using the following:

ruby blitline_listener.rb

This will start the sinatra listener. You will need to leave this server running, so open up a new console window and continue with the instructions below.

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Route Blitline Callback to Your Localhost Machine:

 

We will create a localhost SSH tunnel so that Blitline server can talk to your localhost machine.

gem install localtunnel

(There are more secure alternatives to this, we recommend ForwardHQ , but localtunnel is free)

localtunnel -k ~/.ssh/id_rsa.pub 4567

You will get some output like:

This localtunnel service is brought to you by Twilio.
Port 4567 is now publicly accessible from http://3un3.localtunnel.com ...

It is important to note the url identified by this output. It will be different every time. Notice that in the example above, the url is "http://3un3.localtunnel.com" This url will be used in the next section.

Leave this localhost tunnel running and open a new console window, and continue with the instructions below...

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Call Blitline with a Postback URL:

 

You can call Blitline by simply using a curl call.

The APPLICATION_ID and the LOCAL_TUNNEL_URL below need to be replaced with your Blitline Application ID and the url determined in the previous section.

curl 'http://api.blitline.com/job' -d json='{ "application_id": "<APPLICATION_ID>", "postback_url": "<LOCAL_TUNNEL_URL>/callback","src" : "http://www.google.com/logos/2011/yokoyama11-hp.jpg", "functions" : [ {"name": "blur", "params" : {"radius" : 0.0, "sigma" : 2.0}, "save" : { "image_identifier" : "MY_CLIENT_ID" }} ]}'

Once you copy and past that curl command into a console, the sinatra server we started in the first section should output the results of the callback from Blitline.

This output should look something like:

{"results"=>"{"original_meta":{"width":421,"height":163},"images":[{"image_identifier":"MY_CLIENT_ID","s3_url":"http://s3.amazonaws.com/blitline/2012112319/20/5SVBt56phqNtHarXvlyUSZA.jpg","meta":{"width":421,"height":163}}],"job_id":"2_5dwX1cNQP97byPNb57K4g"}"}

This is the JSON returned from Blitline after it has completed processing your image.