uwsgi-as-a-systemd-service with python3 and bottle framework

gistfile1.txt

*****************************************************
*** APPROACH 1: install uwsgi as a system package ***
*****************************************************

install packages
----------------
apt install uwsgi uwsgi-plugin-python3

Configure uwsgi daemon
----------------------
cat /etc/uwsgi/apps-available/site_inventory_http.ini
sudo ln -s /etc/uwsgi/apps-available/site_inventory_http.ini /etc/uwsgi/apps-enabled/

[uwsgi]
#strict = true       ; need more info here

# Create a virtual environment for our application
# python3 -m venv bottle-venv
# virtualenv = bottle-venv               		

plugins = python3

# Respawns processes when they die and handles much of the built-in 
# prefork+threading multi-worker management, generally always advised
master = true
enable-threads = true
# processes = n - Adds concurrency to the app by adding n additional processes
# threads = n - Adds additional cuncurrency by adding n additional threads
# As a starting point, one could set processes to the number of CPU cores on
# the machine and threads at 2 per CPU core
processes = 4
threads = 2
# Delete sockets during shutdown
vacuum = true                         
single-interpreter = true
# Shutdown when receiving SIGTERM (default is respawn)
die-on-term = true
need-app = true

# If you need to bind to privileged ports (like 443 for HTTPS), use shared sockets.
# They are created before dropping privileges and can be referenced with the =N syntax,
# where N is the socket number (starting from 0):
shared-socket = :80
http-socket = =0

# Run uwsgi as root but not recommended
#http-socket = 0.0.0.0:80

# Run uwsgi protocol with nginx frontend
#socket = /run/uwsgi/app/site_inventory/socket

chdir = /srv/site_inventory
module = site_inventory:app
# OR: 
#wsgi-file = app.py

# Always avoid running your uWSGI instances as root
# Requires sudo chown -R www-data:www-data /var/log/uwsgi/app for uwsgi logging
uid = www-data
gid = www-data

# logto2 only opens the log file after privileges have been dropped to the specified uid/gid.
logto2 = /var/log/uwsgi/app/site_inventory_http.log
logfile-chown = uid:gid
logfile-chmod = 640

# uWSGI default logging
#log-format = [pid: %(pid)|app: -|req: -/-] %(addr) (%(user)) {%(vars) vars in %(pktsize) bytes} [%(ctime)] %(method) %(uri) => generated %(rsize) bytes in %(msecs) msecs (%(proto) %(status)) %(headers) headers in %(hsize) bytes (%(switches) switches on core %(core))
# Apache-style combined request logging
log-format = %(addr) - %(user) [%(ltime)] "%(method) %(uri) %(proto)" %(status) %(size) "%(referer)" "%(uagent)"

Application: /srv/site_inventory/site_inventory.py EXCERPT
----------------------------------------------------------
...
# this is the hook for uWSGI to run the Bottle based application
app = bottle.default_app()


systemd commands
----------------
systemctl list-units --type=service --state=active
systemctl status uwsgi
systemctl start uwsgi
systemctl stop uwsgi
journalctl -fu uwsgi # tail log

Test (and get RESPONSE Header)
------------------------------
wget -S -q -O - http://127.0.0.1


**************************************************************************
*** APPROACH 2: install uwsgi as a pip package in a virtual environment***
**************************************************************************

which python3

cd /home/bruno/usgi_project
python3 -m venv uwsgi_venv

source uwsgi_project/uwsgi_venv/bin/activate

which python3

python3 -m pip download  uWSGI
python3 -m pip download bottle

python3 -m pip install uWSGI-2.0.19.1.tar.gz
python3 -m pip install bottle-0.12.19-py3-none-any.whl

python3 -m pip list

uwsgi

deactivate



sudo usermod bruno -a -G www-data


/etc/systemd/system/bottle.ini
RHES7 --> https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/system_administrators_guide/chap-managing_services_with_systemd
          -->10.6.2. Creating Custom Unit Files
-------------------------------------------------------------------------------
[Unit]
Description=uWSGI instance to serve myproject
After=network.target

[Service]
User=bruno
Group=www-data
WorkingDirectory=/home/bruno/uwsgi_project
Environment="PATH=/home/bruno/uwsgi_project/uwgi_venv/bin"
ExecStart=/home/bruno/uwsgi_project/uwsgi_venv/bin/uwsgi --ini bottle.ini

[Install]
WantedBy=multi-user.target

/home/bruno/uwsgi_project/bottle.ini
-------------------------------------------------------------------------------
[uwsgi]
# Specify virtual environment for our application
virtualenv = uwsgi_venv     

# Respawns processes when they die and handles much of the built-in 
# prefork+threading multi-worker management, generally always advised
master = true
enable-threads = true
# processes = n - Adds concurrency to the app by adding n additional processes
# threads = n - Adds additional cuncurrency by adding n additional threads
# As a starting point, one could set processes to the number of CPU cores on
# the machine and threads at 2 per CPU core
processes = 4
threads = 2
# Delete sockets during shutdown
vacuum = true                         
single-interpreter = true
# Shutdown when receiving SIGTERM (default is respawn)
die-on-term = true
need-app = true

#socket = /run/uwsgi/app/bottle/socket
http-socket = 127.0.0.1:8000

chdir = /home/bruno/uwsgi_project
module = app:app
#OR: 
#wsgi-file = app.py

#master process controls the worker tasks, restarting them when they stop, among other things.
#Always avoid running your uWSGI instances as root
#Requires sudo chown -R www-data:www-data /var/log/uwsgi/app for uwsgi logging
#uid = bruno
#gid = bruno
logto = /home/bruno/uwsgi_project/bottle.log


/home/bruno/uwsgi_project/app.py
-------------------------------------------------------------------------------
import bottle
from bottle import route, run, Response

# a basic URL route to test whether Bottle is responding properly
@route('/')
def index():
    return Response("Open the bottle and enjoy!\n")

# these two lines are only used for python myapp.py
if __name__ == '__main__':
    run(host='0.0.0.0', port=8000, debug=True, reloader=True)

# this is the hook for uwsgi to run Bottle
app = application = bottle.default_app()