docs: Add Django Example to Python Examples Folder (grafana#472)

* Add django example

examples/python/django/.env.dev

@@ -0,0 +1,10 @@
+DEBUG=1
+SECRET_KEY=foo
+DJANGO_ALLOWED_HOSTS=localhost 127.0.0.1 [::1] web
+SQL_ENGINE=django.db.backends.postgresql
+SQL_DATABASE=hello_django_dev
+SQL_USER=hello_django
+SQL_PASSWORD=hello_django
+SQL_HOST=db
+SQL_PORT=5432
+DATABASE=postgres

examples/python/django/.env.dev.sample

@@ -0,0 +1,10 @@
+DEBUG=1
+SECRET_KEY=foo
+DJANGO_ALLOWED_HOSTS=localhost 127.0.0.1 [::1] web
+SQL_ENGINE=django.db.backends.postgresql
+SQL_DATABASE=hello_django_dev
+SQL_USER=hello_django
+SQL_PASSWORD=hello_django
+SQL_HOST=db
+SQL_PORT=5432
+DATABASE=postgres

examples/python/django/.gitignore

@@ -0,0 +1,5 @@
+*.pyc
+__pycache
+.DS_Store
+.env.prod
+.env.prod.db

examples/python/django/Dockerfile.load-generator

@@ -0,0 +1,9 @@
+FROM python:3.9
+
+RUN pip3 install requests
+
+COPY load-generator.py ./load-generator.py
+
+ENV PYTHONUNBUFFERED=1
+
+CMD [ "python", "load-generator.py" ]

examples/python/django/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 Michael Herman
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

examples/python/django/README.md

@@ -0,0 +1,15 @@
+# Dockerizing Django with Pyroscope, Postgres, Gunicorn, and Nginx
+This is a simple rideshare example that adds Pyroscope to a Django application and uses it to profile various routes
+
+### Development
+Uses the default Django development server.
+
+1. Rename *.env.dev-sample* to *.env.dev*.
+1. Update the environment variables in the *docker-compose.yml* and *.env.dev* files.
+1. Build the images and run the containers:
+
+    ```sh
+    $ docker-compose up -d --build
+    ```
+
+    Test it out at [http://localhost:8000](http://localhost:8000). The "app" folder is mounted into the container and your code changes apply automatically.

examples/python/django/app/Dockerfile

@@ -0,0 +1,33 @@
+# pull official base image
+FROM python:3.9
+
+# set work directory
+WORKDIR /usr/src/app
+
+# set environment variables
+ENV PYTHONDONTWRITEBYTECODE 1
+ENV PYTHONUNBUFFERED 1
+
+# install psycopg2 dependencies
+# RUN apk update \
+#     && apk add libffi-dev postgresql-dev gcc python3-dev musl-dev
+
+RUN apt-get update -y
+RUN apt-get install -y postgresql postgresql-client netcat gcc python3-dev musl-dev
+
+
+# install dependencies
+RUN pip install --upgrade pip
+COPY ./requirements.txt .
+RUN pip install -r requirements.txt
+
+# copy entrypoint.sh
+COPY ./entrypoint.sh .
+RUN sed -i 's/\r$//g' /usr/src/app/entrypoint.sh
+RUN chmod +x /usr/src/app/entrypoint.sh
+
+# copy project
+COPY . .
+
+# run entrypoint.sh
+ENTRYPOINT ["/usr/src/app/entrypoint.sh"]

examples/python/django/app/Dockerfile.prod

@@ -0,0 +1,72 @@
+###########
+# BUILDER #
+###########
+
+# pull official base image
+FROM python:3.9.6-alpine as builder
+
+# set work directory
+WORKDIR /usr/src/app
+
+# set environment variables
+ENV PYTHONDONTWRITEBYTECODE 1
+ENV PYTHONUNBUFFERED 1
+
+# install psycopg2 dependencies
+RUN apk update \
+    && apk add postgresql-dev gcc python3-dev musl-dev
+
+# lint
+RUN pip install --upgrade pip
+RUN pip install flake8==3.9.2
+COPY . .
+RUN flake8 --ignore=E501,F401 .
+
+# install dependencies
+COPY ./requirements.txt .
+RUN pip wheel --no-cache-dir --no-deps --wheel-dir /usr/src/app/wheels -r requirements.txt
+
+
+#########
+# FINAL #
+#########
+
+# pull official base image
+FROM python:3.9.6-alpine
+
+# create directory for the app user
+RUN mkdir -p /home/app
+
+# create the app user
+RUN addgroup -S app && adduser -S app -G app
+
+# create the appropriate directories
+ENV HOME=/home/app
+ENV APP_HOME=/home/app/web
+RUN mkdir $APP_HOME
+RUN mkdir $APP_HOME/staticfiles
+RUN mkdir $APP_HOME/mediafiles
+WORKDIR $APP_HOME
+
+# install dependencies
+RUN apk update && apk add libpq
+COPY --from=builder /usr/src/app/wheels /wheels
+COPY --from=builder /usr/src/app/requirements.txt .
+RUN pip install --no-cache /wheels/*
+
+# copy entrypoint.prod.sh
+COPY ./entrypoint.prod.sh .
+RUN sed -i 's/\r$//g'  $APP_HOME/entrypoint.prod.sh
+RUN chmod +x  $APP_HOME/entrypoint.prod.sh
+
+# copy project
+COPY . $APP_HOME
+
+# chown all the files to the app user
+RUN chown -R app:app $APP_HOME
+
+# change to the app user
+USER app
+
+# run entrypoint.prod.sh
+ENTRYPOINT ["/home/app/web/entrypoint.prod.sh"]

examples/python/django/app/entrypoint.prod.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+if [ "$DATABASE" = "postgres" ]
+then
+    echo "Waiting for postgres..."
+
+    while ! nc -z $SQL_HOST $SQL_PORT; do
+      sleep 0.1
+    done
+
+    echo "PostgreSQL started"
+fi
+
+exec "$@"

examples/python/django/app/entrypoint.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+if [ "$DATABASE" = "postgres" ]
+then
+    echo "Waiting for postgres..."
+
+    while ! nc -z $SQL_HOST $SQL_PORT; do
+      sleep 0.1
+    done
+
+    echo "PostgreSQL started"
+fi
+
+python manage.py flush --no-input
+python manage.py migrate
+
+exec "$@"

examples/python/django/app/hello_django/__init__.py

@@ -0,0 +1 @@
+

examples/python/django/app/hello_django/asgi.py

@@ -0,0 +1,16 @@
+"""
+ASGI config for hello_django 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/3.2/howto/deployment/asgi/
+"""
+
+import os
+
+from django.core.asgi import get_asgi_application
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'hello_django.settings')
+
+application = get_asgi_application()

examples/python/django/app/hello_django/settings.py

@@ -0,0 +1,147 @@
+"""
+Django settings for hello_django project.
+
+Generated by 'django-admin startproject' using Django 3.2.6.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/3.2/topics/settings/
+
+For the full list of settings and their values, see
+https://docs.djangoproject.com/en/3.2/ref/settings/
+"""
+
+import os
+import pyroscope
+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/3.2/howto/deployment/checklist/
+
+SECRET_KEY = os.environ.get("SECRET_KEY")
+
+DEBUG = int(os.environ.get("DEBUG", default=0))
+
+# 'DJANGO_ALLOWED_HOSTS' should be a single string of hosts with a space between each.
+# For example: 'DJANGO_ALLOWED_HOSTS=localhost 127.0.0.1 [::1]'
+ALLOWED_HOSTS = os.environ.get("DJANGO_ALLOWED_HOSTS").split(" ")
+
+
+# Application definition
+
+INSTALLED_APPS = [
+    "django.contrib.admin",
+    "django.contrib.auth",
+    "django.contrib.contenttypes",
+    "django.contrib.sessions",
+    "django.contrib.messages",
+    "django.contrib.staticfiles",
+    "rest_framework",
+    "ride_share",
+]
+
+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 = 'hello_django.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 = 'hello_django.wsgi.application'
+
+
+# Database
+# https://docs.djangoproject.com/en/3.2/ref/settings/#databases
+
+DATABASES = {
+    "default": {
+        "ENGINE": os.environ.get("SQL_ENGINE", "django.db.backends.sqlite3"),
+        "NAME": os.environ.get("SQL_DATABASE", BASE_DIR / "db.sqlite3"),
+        "USER": os.environ.get("SQL_USER", "user"),
+        "PASSWORD": os.environ.get("SQL_PASSWORD", "password"),
+        "HOST": os.environ.get("SQL_HOST", "localhost"),
+        "PORT": os.environ.get("SQL_PORT", "5432"),
+    }
+}
+
+
+# Password validation
+# https://docs.djangoproject.com/en/3.2/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/3.2/topics/i18n/
+
+LANGUAGE_CODE = 'en-us'
+
+TIME_ZONE = 'UTC'
+
+USE_I18N = True
+
+USE_L10N = True
+
+USE_TZ = True
+
+
+# Static files (CSS, JavaScript, Images)
+# https://docs.djangoproject.com/en/3.2/howto/static-files/
+
+STATIC_URL = "/static/"
+STATIC_ROOT = BASE_DIR / "staticfiles"
+
+MEDIA_URL = "/media/"
+MEDIA_ROOT = BASE_DIR / "mediafiles"
+
+
+# Default primary key field type
+# https://docs.djangoproject.com/en/3.2/ref/settings/#default-auto-field
+
+DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
+
+pyroscope.configure(
+	app_name       = "django-ride-sharing-app",
+	server_address = "http://pyroscope:4040",
+	# tags           = {
+    #     "region":   f'{os.getenv("REGION")}',
+	# }
+)