Instalation guide:

Basic configurations on linux server

# Logged in as root

# Update the system
apt-get update
apt-get upgrade

# Config locale related settings (to remove locale warnings):
export LANGUAGE=en_US.UTF-8
export LANG=en_US.UTF-8
export LC_ALL=en_US.UTF-8
locale-gen en_US.UTF-8
dpkg-reconfigure locales

# Add, config new user and login as him
adduser playlistapi
usermod -aG sudo playlistapi
su - playlistapi

# Config firewall
sudo apt-get install -y ufw
sudo ufw allow ssh
sudo ufw allow http
sudo ufw allow 443/tcp
sudo ufw --force enable
sudo ufw status

Install and Config Postgres

# Update and install necessary software
sudo apt-get update
sudo apt-get install postgresql postgresql-contrib

# Login as postgres and config the db. Then exit back to previous user
sudo -i -u postgres
createdb playlist_api
createdb test_database # For testing reasons
psql
alter user postgres password 'YOUR POSTGRES PASS';
\q
exit

Install and Config Elasticsearch

# Install java related requirements
sudo apt-get update
sudo apt-get install default-jre
sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java8-installer
sudo apt-get update

# Download and Install current elastic (See current version here: https://www.elastic.co/downloads/elasticsearch )
wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.2.3.deb
sudo dpkg -i elasticsearch-6.2.3.deb

# Config
sudo nano /etc/elasticsearch/elasticsearch.yml
Change: network.host: 0.0.0.0

sudo systemctl enable elasticsearch.service
sudo systemctl start elasticsearch

# Test if it works. (If not see below)
curl -X GET 'http://localhost:9200'

# If error, check memory of the server. Change it to apropriate level following the steps below
sudo service elasticsearch status
sudo nano /etc/elasticsearch/jvm.options
(Change the size of the storage https://stackoverflow.com/questions/31677563/connection-refused-error-on-elastic-search)
    e.g.
    -Xms1g --> -Xms128m
    -Xms1g --> -Xmx128m
sudo systemctl restart elasticsearch

Install and Config the Project

# Clone the project from bitbucket
cd /home/playlistapi
git clone https://stavros0x00@bitbucket.org/stavros0x00/playlist_api.git

# Install python 3.6 and related packages:
sudo add-apt-repository ppa:jonathonf/python-3.6
sudo apt-get update
sudo apt-get install build-essential python3-dev python3.6 python3.6-dev python3-setuptools python-dev graphviz libgraphviz-dev pkg-config python-pygraphviz python3-distutils

#  Install pipenv and needed python packages for the project
sudo apt-get install python3-pip
sudo pip3 install pipenv
cd /home/playlistapi/playlist_api
pipenv install

# Needed Enviroment keys in an .env file
# Create .env file in /home/playlistapi/playlist_api with the env variables below
* FLASK_APP=run.py
* SECRET_KEY=(YOUR APP SECRET KEY HERE)
* DATABASE_URL=postgresql://postgres:{YOUR POSTGRES PASS}@localhost:5432/playlist_api
* TEST_DATABASE_URL=postgresql://postgres:{YOUR POSTGRES PASS}@localhost:5432/test_database
* ELASTICSEARCH_URI=http://localhost:9200
* SENTRY_KEY= (optional)
* SPOTIPY_CLIENT_ID=(https://developer.spotify.com/dashboard/)
* SPOTIPY_CLIENT_SECRET=(https://developer.spotify.com/dashboard/)
* LAST_FM_API_KEY=(https://www.last.fm/api/authentication)
* LAST_FM_SHARED_SECRET=(https://www.last.fm/api/authentication)
* MAIL_USERNAME=(optional, for connecting to gmail server)
* MAIL_PASSWORD=(optional, for connecting to gmail server)
* NOTIFICATIONS_EMAIL=(optional, your email for notifications)
* SENDER_EMAIL=(optional, from who to send email)

# Run the virtual enviroment. And populate the database creating the schema and running the necessary scripts.
pipenv shell
flask db upgrade
mkdir /home/playlistapi/playlist_api/api/pickled_files/
python scripts/crawl_playlists.py
python scripts/sync_db_elastic.py

# Config uwsgi
touch playlist_api.sock
touch uwsgi.log
echo '[uwsgi]
module = run:app

master = true
processes = 5

socket = playlist_api.sock
chmod-socket = 660
vacuum = true
logto = /home/playlistapi/playlist_api/uwsgi.log
for-readline = /home/playlistapi/playlist_api/.env
  env = %(_)
endfor =

enable-threads = true
die-on-term = true' > playlist_api.ini


sudo nano /etc/systemd/system/playlist_api.service
(Copy the below lines in the created file and save)
(Where the lines for the virtual enviroment, replace with yours location)
[Unit]
Description=uWSGI instance to serve myproject
After=network.target

[Service]
User=playlistapi
Group=www-data
WorkingDirectory=/home/playlistapi/playlist_api
Environment="PATH=/home/playlistapi/.local/share/virtualenvs/playlist_api-KjQVwPM-/bin"
ExecStart=/home/playlistapi/.local/share/virtualenvs/playlist_api-KjQVwPM-/bin/uwsgi --ini playlist_api.ini

[Install]
WantedBy=multi-user.target

sudo systemctl start playlist_api
sudo systemctl enable playlist_api

sudo systemctl restart playlist_api

Install and Config the Nginx Server

# Install nginx
sudo apt-get update
sudo apt-get install nginx

# Config nginx
sudo nano /etc/nginx/sites-available/playlist_api
(Copy the below lines in the created file and save)
(Replace the server_domain_or_IP with appropriate ip or hostname)
server {
    listen 80;
    server_name server_domain_or_IP;
    location / {
    include uwsgi_params;
    uwsgi_pass unix:/home/playlistapi/playlist_api/playlist_api.sock;
}

}

sudo ln -s /etc/nginx/sites-available/playlist_api /etc/nginx/sites-enabled
sudo nginx -t
sudo systemctl restart nginx
sudo ufw allow 'Nginx Full'