Deploying a Panel App on Linode with Nginx and Supervisor

how-to-deploy-panel-linode-nginx.md

Deploying Python Panel with Nginx

Inspired by these documents:

• https://panel.holoviz.org/user_guide/Server_Configuration.html
• https://docs.bokeh.org/en/latest/docs/user_guide/server/deploy.html
• https://simpleisbetterthancomplex.com/tutorial/2016/10/14/how-to-deploy-to-digital-ocean.html

Prepare the Server

ssh root@<ip-address>

sudo apt-get update
sudo apt-get -y upgrade

sudo apt-get -y install build-essential libpq-dev

sudo apt-get -y install nginx

sudo apt-get -y install supervisor

sudo systemctl enable supervisor
sudo systemctl start supervisor

sudo apt-get -y install python3-virtualenv

Create a User

adduser <USER>
gpasswd -a <USER> sudo
su - <USER>

Clone the Project

1. Create a github Personal Access Token (classic with repo[x] priviledge): https://github.com/settings/tokens
2. Clone the desired deployment project

git clone https://github.com/<username>/<project>.git

when prompted, use your github username and paste the access token for password.

Install Requirements

virtualenv .
source bin/activate
cd <project>
pip install -r requirements.txt

Test the app

panel serve <project>/app.py --port 5100 --allow-websocket-origin=<ip-address>

Go to <ip-address>:5100 in your browser
ctrl-C to close the app

Perpare Supervisor

cd
vim bin/panel_start

   #!/bin/bash

   DIR=/home/<USER>/<project>

   cd $DIR
   source ../bin/activate

   export PYTHONPATH=$DIR:$PYTHONPATH

   exec panel serve <project>/app.py --port 5100 --allow-websocket-origin=<ip-address>
   # Add more for horizontal scaling

chmod u+x bin/panel_start
chmod o+rx /home/<USER>/
mkdir logs

sudo vim /etc/supervisor/conf.d/<project>.conf

   [program:<project>]
   command=/home/<USER>/bin/panel_start
   user=<USER>
   autostart=true
   autorestart=true
   redirect_stderr=true
   stdout_logfile=/home/<USER>/logs/panel-error.log

Update and run Supervisor:

sudo supervisorctl reread
sudo supervisorctl update
sudo supervisorctl restart <project>
sudo supervisorctl status <project>

Deploying with Nginx

sudo vim /etc/nginx/sites-available/<project>

   upstream myapp { 
       least_conn;            # Use the least-connected strategy 
       server 127.0.0.1:5100; 
      # Add more for horizontal scaling
       
   } 
    
   server { 
    
       location / { 
           proxy_pass http://myapp; 
    
           # all other settings unchanged 
           proxy_set_header Upgrade $http_upgrade; 
           proxy_set_header Connection "upgrade"; 
           proxy_http_version 1.1; 
           proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; 
           proxy_set_header Host $host:$server_port; 
           proxy_buffering off; 
       } 
    
   }

sudo ln -s /etc/nginx/sites-available/<project> /etc/nginx/sites-enabled/<project>
sudo rm /etc/nginx/sites-enabled/default
sudo service nginx restart

The Final Test

Navigate to in your browser.

If you don't see your panel app:

tail logs/panel-error.log
sudo tail /var/log/nginx/error.log
sudo tail /var/log/nginx/access.log