Dairy_App Backend

Python Diary Web App built on top of Django + Vue + Bootstrap + MySQL (Adaptive to Phone and Computer)

See Vue Frontend here

Installation

Local Environment

1. Clone source code

$ git clone [email protected]:Cecil-Zhang/dairy_app.git
$ cd /path/to/dairy_app/

2. Create a virtual environment

$ python3 -m venv venv  # create a virtual environment in root folder
$ . venv/bin/activate   # activate virtual environtment

3. Install python library

$ pip install -r requirements.txt # install dependencies required by dairy app

4. Configure database
   • Configure database connection in mysite/mysite/settings.py

     DATABASES = {
             'default': {
             'ENGINE': 'django.db.backends.mysql',
             'NAME': 'dairy',
             'USER': 'dairy',
             'PASSWORD': '****',
             'OPTIONS': {
                         'charset': 'utf8mb4',
                         'use_unicode': True, }
         }
     }
     

   • Apply DDL

     $ python mysite/manage.py migrate
     

5. Collect static files into static folder STATICFILES_FINDERS

   $ python mysite/manage.py runserver
   

6. Start server

   $ python mysite/manage.py runserver
   

Production Environment

Data flow illustration

web client <-> Nginx <-> Unix Socket <-> uWSGI <-> Django

Dairy Configuration

Step 1 ~ 5 in Local Environment Here we will not run development server with manage.py, host in WSGI server with wsgi.py instead

uWSGI and Unix Socket Configuration

Flow work as following

 Unix Socket <-> uWSGI <-> Django

We use uWSGI as our WSGI server with its emperor mode

1. uWSGI emperor mode configuration file, save it as emperor.ini in /etc/uwsgi/

   [uwsgi]
   emperor = /etc/uwsgi/vassals
   uid = www-data
   gid = www-data
   vassal-set = threads=2
   vassal-set = chmod-socket=660
   

2. Start dairy_app as vassal of uWSGI emperor, save it as dairy_app.ini in /etc/uwsgi/vassals/

   [uwsgi]
   chdir = /path/to/dairy_app/mysite/
   module = mysite.wsgi          # start of dairy_app
   logto = /var/log/uwsgi/%n.log # log file
   socket = /run/uwsgi/%n.sock   # unix socket file
   master = true
   vacum = true
   

3. Start uWSGI

$ /path/to/dairy_app/venv/bin/uwsgi --ini /etc/uwsgi/emperor.ini

4. After starting, you should see a unix socket file dairy_app.sock in /run/uwsgi/ and logger file in /var/log/uwsgi

Nginx Configuration

Use nginx as proxy server, the flow works as following

 web client <-> Nginx <-> Unix Socket

1. Install Nginx
2. Configure Nginx
   • Configure Nginx listening path and connect to django (unix socket here)

   server {
       listen      80;
       server_name dairy_app; # substitute your machine's IP address or FQDN
       charset     utf-8;
       client_max_body_size 75M;   # adjust to taste
       
       # Django media
       location /media  {
           alias /var/dairy_app/media;  # your Django project's media files - amend as required      
       }
       
       # location /static {
       #     alias /home/ubuntu/git/dairy_app/mysite/static; # your Django project's static files - amend as required
       #  }
   
       # Finally, send all non-media requests to the Django server.
       location /api/v1 {
           rewrite ^/api/v1(.*) $1 break;
           uwsgi_pass  django;
           include     /home/ubuntu/git/dairy_app/uwsgi_conf/uwsgi_params; # the uwsgi_params file you installed 
       }
       ...
   }  
   

   • Save it to /etc/nginx/sites-available/dairy_app.conf, example
   • Create Symlink so that Nginx can see it

   sudo ln -s /etc/nginx/sites-available/dairy_app.conf /etc/nginx/sites-enabled/
   

3. Start Nginx

   nginx start
   

Start uWSGI with systemctl

1. Save it as /etc/systemd/system/emperor.uwsgi.service

[Unit]
Description=Dairy Diary App running on uWSGI
After=syslog.target

[Service]
User=www-data
Group=www-data
RuntimeDirectory=uwsgi
ExecStart=/path/to/dairy_app/venv/bin/uwsgi --ini /etc/uwsgi/emperor.ini
Environment="PATH=/path/to/dairy_app/venv/bin"
KillSignal=SIGQUIT
Type=notify
NotifyAccess=all

[Install]
WantedBy=multi-user.target

2. Manage uWSGI as systemd service

systemctl start/status/stop emperor.uwsgi.service

Development Notes

• How to apply DB change

  1. Change your models (in models.py).
  2. Run python manage.py makemigrations to create migrations for those changes
  3. Run python manage.py sqlmigrate APP_NAME IDX to view db changes
  4. Run python manage.py migrate to apply those changes to the database.

• How to local run Django with uWSGI uwsgi --http :8000 --module mysite.wsgi

Management command

• Export Diary to PDF: python manage.py exportpdf

To set up scheduler job to export diaries as pdf

1. Create crontab task sudo crontab -e
2. Append following task to the crontab @monthly /path/to/venv/bin/python /path/to/dairy_app/mysite/manage.py exportpdf
3. Then the first day in each month, all diaries in last month will be exported to BACKUP_ROOT configured in settings.py as pdf

Environment in TecentCloud

Django Directory

/home/ubuntu/git/dairy_app

uWSGI Unit Service

/etc/systemd/system/emperor.uwsgi.service

Notes:

• Running in uWSGI Emperor Mode
• emperor.ini put in /etc/uwsgi/
• app.ini file put in /etc/uwsgi/vassals

Nginx Configuration

• Configuration file in /etc/nginx/sites-available

Reference

API List

http://localhost:8000/users/register/
http://localhost:8000/users/login/
http://localhost:8000/users/logout/
http://localhost:8000/users/info/
http://localhost:8000/users/changePassword/
http://localhost:8000/diary/monthPdf/
http://localhost:8000/diary/upload/
http://localhost:8000/diary/
http://localhost:8000/diary/<int:diary_id>/
http://localhost:8000/diary/<int:diary_id>/files/<int:file_id>/