Setup Facebook React-native sample (empty) project on Ubuntu

setup_howto.txt

# author:
# @Bartosz Kosarzycki
#

sudo apt-get install npm
sudo npm install -g react-native-cli
sudo ln -s /usr/bin/nodejs /usr/bin/node
cd /home/user/your/project/path
react-native init AwesomeProject
cd AwesomeProject
react-native run-android

==================== if something goes wrong:  ==============================
check node.js version
> node --version
v0.10.25

if it's below 0.12 upgrade your node.js:

sudo apt-get install -y curl
curl -sL https://deb.nodesource.com/setup_0.12 | sudo bash -
sudo apt-get install -y nodejs

>  node --version
v0.12.7

=================================================

Check your adb version:
adb version
Android Debug Bridge version 1.0.31

if it's below 1.0.32 upgrade your adb tools
> adb version
Android Debug Bridge version 1.0.32
Revision 09a0d98bebce-android

====== "Unable to download JS bundle" ===========================================
#
# In order to run the Facebook react app you need to start the JS server on the PC and forward port 8081 to the phone
#

> sudo react-native start
(or 
> sudo react-native start > /dev/null 2>&1 &  
to start in the background)

> adb reverse tcp:8081 tcp:8081
(Note that this option is available on devices running android 5.0+ (API 21).!!!)