stage-three

Deploy a Python application behind Nginx that interacts with RabbitMQ/Celery for email sending and logging functionality.

Pre-requisites

Python3 installed
An Ubuntu 22.04 server
Ngrok account with a static domain set up

Steps

Create the log file and set user permissions

  sudo touch /var/log/messaging_system.log && sudo chmod 666 /var/log/messaging_system.log

Edit the .env file with your SMTP username and password, and the username, password, and vhost name you would use to set up rabbitmq
Install python dependencies

   sudo apt update
   sudo apt install -y python3-pip build-essential libssl-dev libffi-dev python3-dev python3-venv python3-flask python3-dotenv

Install rabbitmq and set up a user with permissions

  sudo rabbitmqctl add_user ${USER} ${PASSWORD}

  #add virtual host
  sudo rabbitmqctl add_vhost '${USER}_vhost'
  
  #add user tag
  sudo rabbitmqctl set_user_tags ${USER} '${USER}_tag'
  
  #set permissions
  sudo rabbitmqctl set_permissions -p '${USER}_vhost' ${USER} ".*" ".*" ".*"

Install celery

   sudo apt update
   sudo apt install celery

Set up celery systemd service

Create a celery config file /etc/default/celeryd

  # Name of nodes to start
# here we have a single node
CELERYD_NODES="w1"
# or we could have three nodes:
#CELERYD_NODES="w1 w2 w3"

# Absolute or relative path to the 'celery' command:
CELERY_BIN="/home/ubuntu/stage-three/app/celeryenv/bin/celery"
#CELERY_BIN="/virtualenvs/def/bin/celery"

# App instance to use
# comment out this line if you don't use an app
CELERY_APP="app.celery"
# or fully qualified:
#CELERY_APP="proj.tasks:app"

# Celery working directory
CELERYD_WORKDIR="/home/ubuntu/stage-three/app"

# celery worker user
CELERYD_USER=“ubuntu”
CELERYD_GROUP=“ubuntu”

# How to call manage.py
CELERYD_MULTI="multi"

# Extra command-line arguments to the worker
CELERYD_OPTS="--time-limit=300 --concurrency=8"

# - %n will be replaced with the first part of the nodename.
# - %I will be replaced with the current child process index
#   and is important when using the prefork pool to avoid race conditions.
CELERYD_STATE_DIR=“/var/run/celery”
CELERYD_PID_FILE="/var/run/celery/%n.pid"
CELERYD_LOG_FILE="/var/log/celery/%n%I.log"
CELERYD_LOG_LEVEL="INFO"

# you may wish to add these options for Celery Beat
CELERYBEAT_PID_FILE="/var/run/celery/beat.pid"
CELERYBEAT_LOG_FILE="/var/log/celery/beat.log"

Create the PID and log files and ensure your user owns the files or has appropriate permissions

  sudo mkdir -p /var/run/celery && sudo chown ubuntu:ubuntu /var/run/celery

  sudo mkdir /var/log/celery && sudo chown ubuntu:ubuntu /var/log/celery

Set up the celery service file in /etc/systemd/system/celery.service

  [Unit]
Description=Celery Service
After=network.target

[Service]
Type=forking
User=ubuntu
Group=ubuntu
EnvironmentFile=/etc/default/celeryd
WorkingDirectory=/home/ubuntu/stage-three/app
ExecStartPre=+/bin/bash -c 'mkdir -p /var/run/celery'
ExecStartPre=+/bin/bash -c 'chown ubuntu:ubuntu /var/run/celery'
ExecStart=/bin/bash -c '${CELERY_BIN} -A $CELERY_APP multi start $CELERYD_NODES \
    --pidfile=${CELERYD_PID_FILE} --logfile=${CELERYD_LOG_FILE} \
    --loglevel="${CELERYD_LOG_LEVEL}" $CELERYD_OPTS'
ExecStop=/bin/bash -c '${CELERY_BIN} multi stopwait $CELERYD_NODES \
    --pidfile=${CELERYD_PID_FILE} --logfile=${CELERYD_LOG_FILE} \
    --loglevel="${CELERYD_LOG_LEVEL}"'
ExecReload=/bin/bash -c '${CELERY_BIN} -A $CELERY_APP multi restart $CELERYD_NODES \
    --pidfile=${CELERYD_PID_FILE} --logfile=${CELERYD_LOG_FILE} \
    --loglevel="${CELERYD_LOG_LEVEL}" $CELERYD_OPTS'
Restart=always

[Install]
WantedBy=multi-user.target

Run the systemctl commands to start the service

  #reload the daemon and start and enable the service
  sudo systemctl daemon-reload
  sudo systemctl start celery
  sudo systemctl enable celery

Set up gunicorn as a systemd service in /etc/systemd/system/gunicorn.service

  [Unit]
  Description=Gunicorn instance to serve the stagethree app
  After=network.target
  
  [Service]
  User=ubuntu
  Group=www-data
  WorkingDirectory=/home/ubuntu/stage-three/app
  Environment="PATH=/home/ubuntu/stage-three/app/celeryenv/bin"
  ExecStart=/home/ubuntu/stage-three/app/celeryenv/bin/gunicorn --workers 3 --bind unix:stagethree.sock app:app
  
  [Install]
  WantedBy=multi-user.target

Run the systemctl commands to start the service

  #reload the daemon and start and enable the service
  sudo systemctl daemon-reload
  sudo systemctl start gunicorn
  sudo systemctl enable gunicorn

Install nginx

   sudo apt update
   sudo apt install nginx

Change the owner of the nginx config file to your user and edit the file to include your user instead of www-data

   sudo chown ubuntu:ubuntu /etc/nginx/nginx.conf
   sudo nano /etc/nginx/nginx.conf

Create the nginx config file in /etc/nginx/sites-available/stagethree

  server {
  listen 80;
  server_name localhost;
  
  location / {
  include proxy_params;
  proxy_pass http://unix:/home/ubuntu/stage-three/app/stagethree.sock;
  }
  }

Create a symlink to sites-enabled, delete default config files, and reload nginx

  sudo ln -s /etc/nginx/sites-available/stagethree /etc/nginx/sites-enabled
  sudo rm /etc/nginx/sites-available/default && sudo rm /etc/nginx/sites-enabled/default
  sudo systemctl reload nginx

Install ngrok

Create the ngrok config file if it does not exists in /home/ubuntu/.config/ngrok/ngrok.yml

  version: "2"
  authtoken: <your-token>
  tunnels:
    stagethree: 
      proto: http
      addr: 80
      domain: <your-domain>

Create the ngrok systemd service file in /etc/systemd/system/ngrok.service

  [Unit]
  Description=Start ngrok tunnel on startup
  After=network-online.target
  Wants=network-online.target systemd-networkd-wait-online.service
  
  [Service]
  ExecStart=/usr/local/bin/ngrok start --all --config /home/ubuntu/.config/ngrok/ngrok.yml
  ExecReload=/bin/kill -HUP $MAINPID
  KillMode=process
  IgnoreSIGPIPE=true
  Restart=always
  RestartSec=3
  Type=simple
  
  [Install]
  WantedBy=multi-user.target

Run the systemctl commands to start the service

  #reload the daemon and start and enable the service
  sudo systemctl daemon-reload
  sudo systemctl start ngrok
  sudo systemctl enable ngrok

Sarahligbe/stage-three

stage-three

Pre-requisites

Steps