Django hello world

django_helloworld/Dockerfile

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+# Dockerfile
+FROM python:3.9-slim
+
+# Set environment variables
+ENV PYTHONDONTWRITEBYTECODE 1
+ENV PYTHONUNBUFFERED 1
+
+# Install dependencies
+RUN pip install --upgrade pip
+RUN pip install django psycopg2-binary
+
+# Create and set the working directory
+WORKDIR /app
+
+# Copy project files to the working directory
+COPY . /app
+
+# Expose the port
+EXPOSE 8000
+
+# Run Django development server
+CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]

django_helloworld/README.md

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+To set up a PostgreSQL Docker container and connect it to a simple Django "Hello World" app running in another Docker container, follow these steps:
+
+### Step 1: Create the Docker Network
+
+Create a custom Docker network so that the Django app and PostgreSQL can communicate with each other.
+
+```bash
+docker network create my_network
+```
+
+### Step 2: Start the PostgreSQL Container
+
+Run the PostgreSQL container and connect it to the `my_network` network.
+
+```bash
+docker run --name my_postgres -e POSTGRES_USER=myuser -e POSTGRES_PASSWORD=mypassword -e POSTGRES_DB=mydatabase --network my_network -d postgres
+```
+
+### Step 3: Create a Minimal Django Project
+
+1. Create a new directory for your Django project:
+
+   ```bash
+   mkdir my_django_app
+   cd my_django_app
+   ```
+
+2. Create a `Dockerfile` for the Django app:
+
+   ```Dockerfile
+   # Dockerfile
+   FROM python:3.9-slim
+
+   # Set environment variables
+   ENV PYTHONDONTWRITEBYTECODE 1
+   ENV PYTHONUNBUFFERED 1
+
+   # Install dependencies
+   RUN pip install --upgrade pip
+   RUN pip install django psycopg2-binary
+
+   # Create and set the working directory
+   WORKDIR /app
+
+   # Copy project files to the working directory
+   COPY . /app
+
+   # Expose the port
+   EXPOSE 8000
+
+   # Run Django development server
+   CMD ["python", "manage.py", "runserver", "0.0.0.0:8000"]
+   ```
+
+3. Initialize a Django project:
+
+   ```bash
+   docker run --rm -v $(pwd):/app -w /app python:3.9-slim /bin/bash -c "pip install django && django-admin startproject myproject ."
+   ```
+
+### Step 4: Configure Django to Use PostgreSQL
+
+Edit the `myproject/settings.py` file to point to the PostgreSQL container:
+
+```python
+# settings.py
+
+DATABASES = {
+    'default': {
+        'ENGINE': 'django.db.backends.postgresql',
+        'NAME': 'mydatabase',
+        'USER': 'myuser',
+        'PASSWORD': 'mypassword',
+        'HOST': 'my_postgres',
+        'PORT': '5432',
+    }
+}
+```
+
+### Step 5: Build and Run the Django Container
+
+1. Build the Docker image for your Django app:
+
+   ```bash
+   docker build -t my_django_app .
+   ```
+
+2. Run the Django container and connect it to the `my_network` network:
+
+   ```bash
+   docker run --name my_django -p 8000:8000 --network my_network -v $(pwd):/app -d my_django_app
+   ```
+
+### Step 6: Migrate the Database
+
+Execute the migration command to set up the database:
+
+```bash
+docker exec -it my_django python manage.py migrate
+```
+
+### Step 7: Create a Simple Hello World View
+
+1. Open the `myproject/urls.py` file and add a simple view:
+
+   ```python
+   from django.http import HttpResponse
+
+   def hello_world(request):
+       return HttpResponse("Hello, world!")
+
+   urlpatterns = [
+       path('', hello_world),
+   ]
+   ```
+
+2. Save and close the file.
+
+### Step 8: Confirm the Django App is Using PostgreSQL
+
+1. Access your Django app by visiting [http://localhost:8000](http://localhost:8000).
+
+2. To confirm the Django app is connected to PostgreSQL:
+
+   - Connect to the PostgreSQL container:
+
+     ```bash
+     docker exec -it my_postgres psql -U myuser -d mydatabase
+     ```
+
+   - List the tables in the database to see if Django has created its tables:
+
+     ```sql
+     \dt
+     ```
+
+   If you see the Django-related tables (like `auth_user`, `django_migrations`, etc.), your Django app is successfully using the PostgreSQL database.
+
+### Recap of Docker Commands
+
+1. **Create network**: `docker network create my_network`
+2. **Run PostgreSQL container**: `docker run --name my_postgres -e POSTGRES_USER=myuser -e POSTGRES_PASSWORD=mypassword -e POSTGRES_DB=mydatabase --network my_network -d postgres`
+3. **Build Django Docker image**: `docker build -t my_django_app .`
+4. **Run Django container**: `docker run --name my_django -p 8000:8000 --network my_network -d my_django_app`
+5. **Migrate database**: `docker exec -it my_django python manage.py migrate`
+
+This setup should give you a basic understanding of how Django connects to a PostgreSQL database in a Dockerized environment.

django_helloworld/manage.py

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+#!/usr/bin/env python
+"""Django's command-line utility for administrative tasks."""
+import os
+import sys
+
+
+def main():
+    """Run administrative tasks."""
+    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'myproject.settings')
+    try:
+        from django.core.management import execute_from_command_line
+    except ImportError as exc:
+        raise ImportError(
+            "Couldn't import Django. Are you sure it's installed and "
+            "available on your PYTHONPATH environment variable? Did you "
+            "forget to activate a virtual environment?"
+        ) from exc
+    execute_from_command_line(sys.argv)
+
+
+if __name__ == '__main__':
+    main()

django_helloworld/myproject/asgi.py

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+"""
+ASGI config for myproject project.
+
+It exposes the ASGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/4.2/howto/deployment/asgi/
+"""
+
+import os
+
+from django.core.asgi import get_asgi_application
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'myproject.settings')
+
+application = get_asgi_application()

django_helloworld/myproject/settings.py

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+"""
+Django settings for myproject project.
+
+Generated by 'django-admin startproject' using Django 4.2.15.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/4.2/topics/settings/
+
+For the full list of settings and their values, see
+https://docs.djangoproject.com/en/4.2/ref/settings/
+"""
+
+from pathlib import Path
+
+# Build paths inside the project like this: BASE_DIR / 'subdir'.
+BASE_DIR = Path(__file__).resolve().parent.parent
+
+
+# Quick-start development settings - unsuitable for production
+# See https://docs.djangoproject.com/en/4.2/howto/deployment/checklist/
+
+# SECURITY WARNING: keep the secret key used in production secret!
+SECRET_KEY = 'django-insecure-4#d%7+)#g&6uy&+7!t%+r#cf%v$%y6*5a4stjql&^7awr$7%o0'
+
+# SECURITY WARNING: don't run with debug turned on in production!
+DEBUG = True
+
+ALLOWED_HOSTS = []
+
+
+# Application definition
+
+INSTALLED_APPS = [
+    'django.contrib.admin',
+    'django.contrib.auth',
+    'django.contrib.contenttypes',
+    'django.contrib.sessions',
+    'django.contrib.messages',
+    'django.contrib.staticfiles',
+]
+
+MIDDLEWARE = [
+    'django.middleware.security.SecurityMiddleware',
+    'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.common.CommonMiddleware',
+    'django.middleware.csrf.CsrfViewMiddleware',
+    'django.contrib.auth.middleware.AuthenticationMiddleware',
+    'django.contrib.messages.middleware.MessageMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
+]
+
+ROOT_URLCONF = 'myproject.urls'
+
+TEMPLATES = [
+    {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'DIRS': [],
+        'APP_DIRS': True,
+        'OPTIONS': {
+            'context_processors': [
+                'django.template.context_processors.debug',
+                'django.template.context_processors.request',
+                'django.contrib.auth.context_processors.auth',
+                'django.contrib.messages.context_processors.messages',
+            ],
+        },
+    },
+]
+
+WSGI_APPLICATION = 'myproject.wsgi.application'
+
+
+# Database
+# https://docs.djangoproject.com/en/4.2/ref/settings/#databases
+
+DATABASES = {
+    'default': {
+        'ENGINE': 'django.db.backends.postgresql',
+        'NAME': 'mydatabase',
+        'USER': 'myuser',
+        'PASSWORD': 'mypassword',
+        'HOST': 'my_postgres',
+        'PORT': '5432',
+    }
+}
+
+
+# Password validation
+# https://docs.djangoproject.com/en/4.2/ref/settings/#auth-password-validators
+
+AUTH_PASSWORD_VALIDATORS = [
+    {
+        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
+    },
+]
+
+
+# Internationalization
+# https://docs.djangoproject.com/en/4.2/topics/i18n/
+
+LANGUAGE_CODE = 'en-us'
+
+TIME_ZONE = 'UTC'
+
+USE_I18N = True
+
+USE_TZ = True
+
+
+# Static files (CSS, JavaScript, Images)
+# https://docs.djangoproject.com/en/4.2/howto/static-files/
+
+STATIC_URL = 'static/'
+
+# Default primary key field type
+# https://docs.djangoproject.com/en/4.2/ref/settings/#default-auto-field
+
+DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'

django_helloworld/myproject/urls.py

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+"""
+URL configuration for myproject project.
+
+The `urlpatterns` list routes URLs to views. For more information please see:
+    https://docs.djangoproject.com/en/4.2/topics/http/urls/
+Examples:
+Function views
+    1. Add an import:  from my_app import views
+    2. Add a URL to urlpatterns:  path('', views.home, name='home')
+Class-based views
+    1. Add an import:  from other_app.views import Home
+    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
+Including another URLconf
+    1. Import the include() function: from django.urls import include, path
+    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
+"""
+from django.contrib import admin
+from django.urls import path
+from django.http import HttpResponse 
+
+
+def hello_world(request):
+    return HttpResponse("Hello, world!")
+
+
+urlpatterns = [
+    path('', hello_world),
+]

django_helloworld/myproject/wsgi.py

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+"""
+WSGI config for myproject project.
+
+It exposes the WSGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/4.2/howto/deployment/wsgi/
+"""
+
+import os
+
+from django.core.wsgi import get_wsgi_application
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'myproject.settings')
+
+application = get_wsgi_application()