Difference between revisions of "Flask"
Line 239: | Line 239: | ||
===Start things=== | ===Start things=== | ||
+ | <syntaxhighlight lang=bash> | ||
service uwsgi start | service uwsgi start | ||
service nginx start | service nginx start | ||
+ | </syntaxhighlight> | ||
That's it. Point your webbrowser to http://<your webserver fdqn>/app1 | That's it. Point your webbrowser to http://<your webserver fdqn>/app1 | ||
Optimization still to be done. I think I start on [https://www.techatbloomberg.com/blog/configuring-uwsgi-production-deployment/ this place] | Optimization still to be done. I think I start on [https://www.techatbloomberg.com/blog/configuring-uwsgi-production-deployment/ this place] |
Revision as of 12:36, 13 July 2021
Basics
Check this[1]
Hello world app:
#!/usr/bin/env python3
from flask import Flask
print(__name__)
app = Flask(__name__)
@app.route('/')
def welcome():
return 'Welcome'
if __name__ == '__main__': # When executed on the commandline (build in webserver)
app.run(host='0.0.0.0',port=5000) # Listen to localhost port 5000, you can also use flask run for options
#app.run(host='0.0.0.0',port=8080,Debug=True) # Run in debug mode, listen to all hosts on port 8080
Run the build-in server listening to all
export FLASK_APP=welcome_app.py
flask run --host=0.0.0.0
welcome_app * Serving Flask app "welcome_app" * Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)
Now you can browse to <serverIP>:5000
Integrate with nginx
Mayor part is from this site [2].
- Install uwgi-emperor and it's python plugin
Configuration files I used.
- Generic configuration file (/etc/uwsgi-emperor/emperor.ini):
[uwsgi] # try to autoload appropriate plugin if "unknown" option has been specified autoload = true # enable master process manager master = true # spawn 2 uWSGI emperor worker processes workers = 2 # automatically kill workers on master's death no-orphans = true # place timestamps into log log-date = true # user identifier of uWSGI processes (same as who runs the web-server) uid = www-data # group identifier of uWSGI processes (same as who runs the web-server) gid = www-data # vassals directory emperor = /etc/uwsgi-emperor/vassals plugins = python3
- Application configuration file (/etc/uwsgi-emperor/vassals/welcome.ini)
[uwsgi] #application's base folder base = /var/www/flask #python module to import app = welcome module = %(app) pythonpath = %(base) #socket file's location socket = /var/local/uwsgi/%n.sock #permissions for the socket file chmod-socket = 664 #the variable that holds a flask application inside the module imported at line #6 callable = app #location of log files logto = /var/log/uwsgi/%n.log plugins = python3
- Create a virtual webserver (port 80 is save enough if you have a secure front-end server)
server {
listen 80 ;
listen [::]:80 ;
root /var/www/flask;
server_name <fqdn>;
location / {
include uwsgi_params;
uwsgi_pass unix:/var/local/uwsgi/welcome.sock;
}
}
Generate web pages
https://flask.palletsprojects.com/en/1.1.x/patterns/templateinheritance/#template-inheritance
Put a index.html in <app-base>/templates/
#!/usr/bin/env python3
from flask import Flask, render_template
print(__name__)
app = Flask(__name__)
@app.route('/html')
def static_page():
return render_template('index.html')
if __name__ == '__main__':
app.run(host='0.0.0.0',port=5000,debug=True)
Microservices and/or more applications on 1 web-server
Starting with this page and additional a lot more we got it working on raspberry pi debian.
- Make python3 the default
cd /usr/bin;rm python;ln -s python3 python
- Install uwsgi and python plugin
apt install uwsgi uwsgi-plugin-python3
- install nginx
apt install nginx-full
I had to make a small change in the nginx configuration;
vi /etc/nginx/conf.d/my.conf
server_names_hash_bucket_size 64;
Super simple apps
In /var/www/flask/app1/app1/py
#!/usr/bin/env python3
from flask import Flask
import os
application = Flask(__name__)
@application.route('/app1')
def app1():
return "App 1 live and kicking"
if __name__ == '__main__':
application.run(host='0.0.0.0', port=8080,debug=True)
/var/www/flask/app2/app2.py
#!/usr/bin/env python3
from flask import Flask
import os
application = Flask(__name__)
@application.route('/app2')
def app2():
return "App 2 live and kicking"
if __name__ == '__main__':
application.run(host='0.0.0.0', port=8080,debug=True)
uwsgi configuration
/etc/uwsgi/apps-available/emperor.xml
<uwsgi>
<autoload>true</autoload>
<no-orphan>true</no-orphan>
<emperor>/etc/uwsgi/vassals-enabled</emperor>
<master>true</master>
<emperor-nofollow>true</emperor-nofollow>
<processes>1</processes>
<uid>www-data</uid>
<gid>www-data</gid>
</uwsgi>
/etc/uwsgi/apps-available/apps.xml
<uwsgi>
<plugins>python3</plugins>
<master>false</master>
<processes>1</processes>
<vaccum>true</vaccum>
<chmod-socket>666</chmod-socket>
<socket>/tmp/%n.sock</socket>
<uid>www-data</uid>
<gid>www-data</gid>
<pythonpath>/var/www/flask/%n</pythonpath>
<module>%n</module>
</uwsgi>
Make them available
cd /etc/uwsgi/apps-enabled
ln -s ../apps-available/emperror.xml
cd /etc/uwsgi/vassals-enabled
ln -s ../apps-available/apps.xml app1.xml
ln -s ../apps-available/apps.xml app2.xml
Create a nginx virtual host
/etc/nginx/sites-enabled/apps.conf
server {
listen 80;
server_name <your webserver fdqn>;
index index.html;
root /var/www/flask;
location /app1 {
include uwsgi_params;
uwsgi_param SCRIPT_NAME /app1;
uwsgi_modifier1 30;
uwsgi_pass unix://tmp/app1.sock;
}
location /app2 {
include uwsgi_params;
uwsgi_param SCRIPT_NAME /app2;
uwsgi_modifier1 30;
uwsgi_pass unix://tmp/app2.sock;
}
}
Start things
service uwsgi start
service nginx start
That's it. Point your webbrowser to http://<your webserver fdqn>/app1
Optimization still to be done. I think I start on this place