nginx proxy_pass does not take affect - nginx

Question

I want to deploy an flask app and followed a tutorial to get this done using nginx.
As the tutorial states I do as follows:
sudo nano /etc/nginx/sites-available/app
this file contains:
server {
listen 80;
server_name server_domain_or_IP;
location / {
include proxy_params;
proxy_pass http://unix:/home/pi/Desktop/python_scripts/internetdisplay/app.sock;
}
}
A systemd Unit service was created and is succesfully running. This created the app.sock file in the 'internetdisplay' directory. Systemctl status app.service results:
● app.service - Gunicorn instance to serve myproject
Loaded: loaded (/etc/systemd/system/app.service; enabled; vendor preset: enabled)
Active: active (running) since Sun 2019-11-10 21:16:49 CET; 16h ago
Main PID: 438 (gunicorn)
Tasks: 4 (limit: 2200)
Memory: 46.4M
CGroup: /system.slice/app.service
├─438 /usr/bin/python2 /usr/bin/gunicorn --workers 3 --bind unix:app.sock -m 007 wsgi:app
├─679 /usr/bin/python2 /usr/bin/gunicorn --workers 3 --bind unix:app.sock -m 007 wsgi:app
├─681 /usr/bin/python2 /usr/bin/gunicorn --workers 3 --bind unix:app.sock -m 007 wsgi:app
└─682 /usr/bin/python2 /usr/bin/gunicorn --workers 3 --bind unix:app.sock -m 007 wsgi:app
Nov 10 21:16:49 raspberrypi systemd[1]: Started Gunicorn instance to serve myproject.
Nov 10 21:16:57 raspberrypi gunicorn[438]: [2019-11-10 21:16:57 +0000] [438] [INFO] Starting gunicorn 19.9.0
Nov 10 21:16:57 raspberrypi gunicorn[438]: [2019-11-10 21:16:57 +0000] [438] [INFO] Listening at: unix:app.sock (438)
Nov 10 21:16:57 raspberrypi gunicorn[438]: [2019-11-10 21:16:57 +0000] [438] [INFO] Using worker: sync
Nov 10 21:16:57 raspberrypi gunicorn[438]: [2019-11-10 21:16:57 +0000] [679] [INFO] Booting worker with pid: 679
Nov 10 21:16:57 raspberrypi gunicorn[438]: [2019-11-10 21:16:57 +0000] [681] [INFO] Booting worker with pid: 681
Nov 10 21:16:57 raspberrypi gunicorn[438]: [2019-11-10 21:16:57 +0000] [682] [INFO] Booting worker with pid: 682
Then I link to sites-enabled and restart nginx:
sudo ln -s /etc/nginx/sites-available/app /etc/nginx/sites-enabled
sudo systemctl restart nginx
But surfing to http://localhost leads to an "this site can't be reached" error

Answer 1

It sounds like your location block is not set up correctly to find your resourses.
I assume that this is not the location of your unix socket:
/home/tasnuva/work/deployment/src/app.sock
Check the following:
systemd unit file is creating a socket in the expected location
the daemon is indeed running and the socket file exists
your nginx config is pointing to the correct socket file.
If none of this tells you anything, please update your question with appropriate error log entries.