PostgreSQL - Tutorial - Install Wagtail and connect it to your service

Learn how to install Wagtail and how to connect it to the OVHcloud Cloud Databases PostgreSQL database service.

Wagtail is a free and open-source content management system (CMS) written in Python. It is popular amongst websites using the Django framework.

 

Requirements

• Access to the OVHcloud Control Panel
• A Public Cloud project in your OVHcloud account
• An up-and-running Cloud Database for PostgreSQL
• A Python environment with a stable version and public network connectivity (Internet)

 

Configure your PostgreSQL instance to accept incoming connections

Before making a connection, we need to verify that our PostgreSQL instance is correctly configured.

Log in to your OVHcloud Control Panel and open your database via the Public Cloud and Databases menus.

 

Step 1: Verify your user roles and password

Select the Users tab. Verify that you have a user and a configured password. If you don't remember the user's password, you can either create a new user or regenerate the password of an existing user. Be careful! By doing so you will need to update all the places where you already use this user/password pair.

This first user avnadmin comes with the following privileges:

  LOGIN
  NOSUPERUSER
  INHERIT
  CREATEDB
  CREATEROLE
  REPLICATION

We rely on official PostgreSQL roles and privileges. You can manage them yourself via CLI or code. So far, user grants and privileges management are not supported via the OVHcloud Control Panel or the OVHcloud API.

Please read the official PostgreSQL documentation to select the right roles for your use case.

In our example, we will simply reset the avnadmin password.

Once created or updated, the user has to be ready and have the status "READY" in the Control Panel.

 

Step 2: Authorize incoming connections from the PostgreSQL client

In this step, select the Configuration tab (Access Control List). By default, a Public Cloud Database does not accept any form of connection from the outside world. This way, we can help prevent intrusive connection attempts.

In the IPs panel, enter the previously found IP of your Python environment and click the add + button.

Click Save changes when you are finished.

 

Instructions

Create and activate a virtual environment

Create an isolated virtual environment for your Python projects that can have unique dependencies, regardless of any other project's dependencies:

$ python3 -m venv mysite/env

Set up your shell to execute Python packages by default:

$ source mysite/env/bin/activate

 

Install Wagtail

Please follow the official documentation to install Wagtail.

Below, you find a resume of the installation process

Use pip, which is packaged with Python, to install Wagtail and its dependencies:

$ pip install wagtail

 

Generate your site

Wagtail provides a start command similar to django-admin startproject. Running wagtail start mysite in your project will generate a new mysite folder with a few Wagtail-specific extras, including the required project settings, a “home” app with a blank HomePage model and basic templates, and a sample “search” app.

Because the folder mysite was already created by venv, run wagtail start with an additional argument to specify the destination directory:

This command will start the mysite folder created in the first step of this guide and the second "mysite" in the command specifies that a new directory should be created in your current home directory and that wagtail should start there.

$ wagtail start mysite mysite

 

Install project dependencies

$ pip install -r requirements.txt

 

Create the database

If you keep Wagtail on default settings, a local SQLlite database will be used inside the project directory. It’s fine for a PoC but not recommended for production, for multiple reasons (performance, security, resiliency, ...). Here we will configure Wagtail to use a Public Cloud Database for PostgreSQL as a backend.

Before creating the database, let's edit the mysite/mysite/settings/base.py file and adapt the connection parameters to the database.

The useful parameters, available in the OVHcloud Control Panel are:

Information	Location
db Host	Dashboard tab, in the Connection information box.
db Port	Dashboard, in the Connection information box.
db Name	Databases tab, usually "defaultdb"
db User	Users tab, usually "avnadmin"
db Password	Displayed in Users tab after resetting.

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': '<db_name>',
        'USER': '<username>',
        'PASSWORD': '<password>',
        'HOST': '<host>',
        'PORT': '<port>',
        'OPTIONS': {
          'sslmode': 'require'
        }
     }
}

Then create the database:

$ python3 manage.py migrate

This command ensures that the tables in your database are matched to the models in your project. Every time you alter your model (e.g. you may add a field to a model) you will need to run this command to update the database.

 

Create an admin user

When logged into the admin site, a superuser has full permissions and can view/create/manage the database.

$ python manage.py createsuperuser

 

Start the server

Run the following command, specifying the IP address of the virtual machine running wagtail.:

python3 manage.py runserver <virtual machine running python ip>:8000

If the previous steps were successful, http://<your VM's IP>:8000 will show you a welcome page:

 

You can now access the administrative area at http://<your VM's IP>/admin:

 

Cleaning up

To clean your Wagtail, make sure it is closed by pressing CTRL+C in the terminal you used to launch it, then delete your installation folder.

rm -rf /home/my/app/path/mysite/

To clean your PostgreSQL, use the OVHcloud Control Panel to delete your managed PostgreSQL service from the Configuration tab:

 

Go further

For more information and tutorials, please see our other Managed Databases & Analytics or Platform as a Service guides. You can also explore the guides for other OVHcloud products and services.