The most practical way to delete all gems and all versions that I run into is the following

gem list | cut -d" " -f1 | xargs gem uninstall -aIx

It works! Just try it out..

Cheers.

This fact has developed a trend where facebook applications’ teams look for cloud solutions when deploying even small apps.

Facebook, listening to this trend, launched an automated way to host your app on cloud by integrating. Now when a facebook developer Creates a new app, in the first screen with all the basic options (app name, urls etc) there is a new option called “Cloud Services”

There you can select to host your facebook application on Heroku Cloud Service and see the following screens

Then you can select the stack (programming language) of your application. Heroku will spawn a process which will automatically build a new initial facebook application in the language specified. The app will have all the basics features, meaning authenticating from facebook, asking and using some basic permissions and rendering a welcome page featuring facebook’s api.

In my case, I chose ruby and thus heroku started a new Sinatra Application, bundled with all the basic gems

source :gemcutter
 
gem "sinatra"
gem "mogli"
gem "json"
gem "httparty"
gem "thin"

The magic part is that now heroku and facebook have complete the whole process for you and the exact application url that is spawned to start on heroku is added in the specified fields of the app configuration page.

To go on and customize your brand new application, just wait for the email from the heroku team that gives you a git repository. You clone, edit and

push heroku master

to deploy your app.

But in most cases this can be tricky or un-doable. In my opinion the most effective way to show your localhost is to use ssh tunneling. This was a common practice back when facebook apps weren’t open to cross site connection and facebook app developers where used to open an ssh tunel to test and run their app in development environement.

Today, I run into the easies way to share your localhost environment via ssh tunel and with the help of a ruby gem called localtunel. The project is developed by Jeff Lindsay and it is supported by Twilio.

Let’s see now how it works.
First of all you need to have ruby installed in your local evnironment. To make sure you have ruby install, run

which ruby

and if you don’t get an answer try installing ruby via rvm.

After that you need to install this gem in the particular ruby version. So try

sudo gem install localtunnel

or try without sudo if you are using an rvm installed ruby.

The last thing to keep in mind is that you need to have an ssh key and provide the path of your ssh public key. In case you don’t have one, follow the instructions from github on how to generate an ssh key .

Supposing that your public key is under ~/.ssh/id_rsa.pub , the last step to take is to run

Savvas-Georgious-MacBook-Pro:.ssh savvasmsc$ localtunnel -k ~/.ssh/id_rsa.pub 80 This localtunnel service is brought to you by Twilio. Port 80 is now publicly accessible from http://3a5f.localtunnel.com ...

for the default port of 80 of a typical webserver or

$ localtunnel -k ~/.ssh/id_rsa.pub 3000

for a typical rails server etc.

When finished remember to kill the tunneling that exposes the local development environment to the whole internet with a Ctrl-C.

You can also have a look into the source code of this implementation here

Amongst the existing graph databases solutions, neo4j is gaining popularity. This can be because of it’s robust implementation, the complete documentation that the neo4j wiki page [http://wiki.neo4j.org]offers and the hooks for languages such as ruby, java, python.

In our case, the goal is to implement a simple user-following-user Ruby on Rails application that stores the following information in the graph database, neo4j.

First we need to install and use jruby. Relying to rvm we run start with

rvm install jruby

Then we need to generate a gemset for jruby and create a rails app, using this gemset.

rvm use jruby-1.6.3
 
rvm gemset create neotest
 
rvm use jruby-1.6.3@neotest

To hook the neo4j database with ruby, we should install and use (require) the neo4j gemset. So we run

gem install neo4j

Now Let’s run a simple test. Create a file and paste the following code.

require "rubygems"
require "neo4j"
 
#domain model
class Waypoint
  include Neo4j::NodeMixin
  #the persistent properties of this class
  property :name, :lon, :lat
  #friend relationships to other persons
  has_n :roads
  index :name
end
 
#populate the db
Neo4j::Transaction.run do
  #the waypoints
  NYC = Waypoint.new :name=>'New York', :lon=>-74.007124, :lat=>40.714550
  SF  = Waypoint.new :name=>'San Francisco', :lon=>-122.420139, :lat=>37.779600
  SEA = Waypoint.new :name=>'Seattle', :lon=>-122.329439, :lat=>47.603560
  #the roads
  NYC.roads << SF
  NYC.roads << SEA
  SEA.roads << SF
end
Neo4j::Transaction.run do
  #do a fulltext search over all Waypoints
  Waypoint.find(:name => 'New York').each { |x|
    puts "Found Waypoint: #{x.name}"
  }
end

Now save the file as neotest.rb

Go to terminal and run the file

$ jruby neotest.rb.

So now we have all the basic setup to start playing with neo4j graph database and ruby. As I just started messing with neo4j and graph database structure, I promise that there will be many following posts about these topics.

1. Generate a dump file of the production database using

heroku pgbackups:capture

This will actually run the pg_dump script on the production server
2. List the backups

heroku pagbackups

3. Get the download-able url of the latest backup listed

heroku pgbackups {lates_backup_name}:url

4. Download the file using the returned url.

Postgresql can use the files comming from the pg_dump with the usage of pg_restore.

Now try this

pg_restore --verbose --clean --no-acl --no-owner -h 127.0.0.1 -U savvasmsc -d sweetlifer_development ~/Downloads/b019.dump