Installing Ruby:


sudo apt-get install -y openssl libreadline6-dev git-core zlib1g libssl-dev libpq-dev 

sudo apt-get install -y libyaml-dev libsqlite3-dev sqlite3

sudo apt-get install -y libxml2-dev libxslt-dev

sudo apt-get install -y autoconf automake libtool bison

cd /usr/src/
sudo wget
sudo tar -xvzf ruby-2.4.0.tar.gz
cd ruby-2.4.0
sudo ./configure --enable-shared --with-openssl-dir=/usr/bin --disable-install-doc --disable-install-rdoc --disable-install-capi 
sudo make install

Before compile: Thu 19 Jan 05:11:11 BRST 2017

After compile: Thu 19 Jan 05:30:19 BRST 2017

It takes around 20 minutes to compile.

Installing Rails without the docs:

sudo gem install rails --no-ri --no-rdoc

you can make it default o not install rubygems documentation:

sudo echo "gem: --no-ri --no-rdoc" >> ~/.gemrc


Installing the PostgreSQL:

Step 1: Update and Install Packages

First, go ahead and update your Pi's packages:

sudo apt-get update

Once this is finished, you can run the following command to grab and install PostgreSQL:

sudo apt-get install postgresql-9.4

It may take a bit to complete, but once it's done, confirm the installation:

which psql

You should get a result like this:

pi@raspberrypi:~ $ which psql  

You should now have a fully functional PostgreSQL database server on your Pi! It's that easy!

In the next steps, we'll configure this server to allow access from external clients (i.e. other computers running a server manager, such as pgAdmin).

Step 2: Modify Configuration

By default, PostgreSQL is configured to only allow access to it's databases from the same machine. This is fine for testing, but our aim is to have a centralized, locally accessible database server. To open access for other machines, we'll need to modify a few configuration files.

First, let's modify the pg_hba.conf file. This controls client authentication and is, by default, configured to only allow local access. Before we make any edits, however, we'll want to create a backup of our default configuration:

sudo cp /etc/postgresql/9.4/main/pg_hba.conf /etc/postgresql/9.4/main/pg_hba.conf.bak

Then, enter the following to open the file for editing:

sudo nano /etc/postgresql/9.4/main/pg_hba.conf

At the end of this file, enter the following line:

host     all     all     md5  

This will allow access from users on our local network (i.e. any client with a 192.168.0.* IP address.

NOTE: You may need to change the first part (192.168) if your router assigns a different network address (like 129.144).

To save your changes to the pg_hba.conf file, enter Ctrl+Xy, and Enter.

Next, we'll need to modify the main postgresql.conf configuration file to allow access from IP addresses other than localhost. But first, make a backup of this file before proceeding:

sudo cp /etc/postgresql/9.4/main/postgresql.conf /etc/postgresql/9.4/main/postgresql.conf.bak

And then:

sudo nano /etc/postgresql/9.4/main/postgresql.conf

And change the following line:

listen_addresses = 'localhost'  


listen_addresses = '*'  

/etc/init.d/postgresql restart

This will allow the PostgreSQL server to accept connections from any IP address. In combination with the changes we made to the pg_hba.conf file, this should allow any clients on the local network access to the server, while still protecting from outside requests. As explained on StackOverflow:

listen_addresses controls which IPs the server will answer on, not which IPs the server will permit connections to authenticate from. It's entirely reasonable and normal to use listen_addresses '*' so the server will accept incoming connections on any ip assigned to an interface on the postgresql server host, while using pg_hba.conf to control access at a finer grained level for which IPs the server will accept logins from for specific databases and users.