Django

Ein mini Tutorial fuer nen Apache2/Debian Django...

Udemy Course: Python and Django Full Stack Web Developer Bootcamp

Gutes Intro: https://tecadmin.net/install-django-on-debian/

Deutsches gutes Intro: https://tutorial.djangogirls.org/de/django_start_project/

Template Commands

IF

{% if VARIABLE %}

<h1>Hallo {{ VARIABLE }}</h1>

{% else %}

<h1>Hallo Welt</h1>

{% endif %}

FOR

{% for item all_items %}

<H1>{{ item.name }}</H1>

{% endfor %}

Embed HTML sourcefiles

{% extends "sourcefile.html" %}

{% include 'sourcefile.html' %}

Views.py Commands

Variables

x = 1

DB Abfragen

Command	SQL
all_items = MyDB.objects.all()	SELECT *
myRow = MyDB.objects.filter(name='Klaus'	WHERE

Python Config

Virtual Environment

pip3 install virtualenv

mkdir /path/to/myapp/venv

cd /path/to/myapp/venv/

virtualenv myprojectenv

source ~/myproject/myprojectenv/bin/activate

Django Config Dateien

Projekt - urls.py

Directory	Dateiname	Beschreibung
Projekt	urls.py
Application	urls.py
Application	views.py

Django Installation

sudo apt-get install python3 python3-pip

python3 -V

Python 3.7.3

pip3 -V

pip 12.0.1 from /usr/lib/python3/dist-packages (python 3.7)

pip3 install Django

django-admin --version

2.1.2

cd /var/www

django-admin startproject django_app

cd django_app

python3 manage.py migrate

python3 manage.py createsuperuser

vi django_app/settings.py

ALLOWED_HOSTS = ['192.168.1.239']

python3 manage.py runserver 0.0.0.0:8000

http://192.168.1.239:8000

http://192.168.1.239:8000/admin

Configure Static Files

vi django_app/settings.py

Fuege 2 Zeilen hinzu...

import os

und unter dem Static Verzeichnis:

STATIC_ROOT = os.path.join(BASE_DIR, 'static/')

Create new App

python manage.py startapp MyApp

cd MyApp

vi urls.py from django.urls import path

from django.urls import path

from . import views

urlpatterns = [

    path("", views.index, name="index"),

]

Die folgende Datei ist zustaendig fuer die Projekt URLs. Hier soll nur ein include passieren, damit die URLs in der App gemanaged werden.

cd MyProject

vi urls.py

urlpatterns = [

    path("MyApp/", include("MyApp.urls")),

    path('admin/', admin.site.urls),

]

cd MyApp

vi view.py

from django.shortcuts import render

from django.http import HttpResponse

def index(request):

    return HttpResponse("Halli Hallo Schwestern")

Django Errors

attempt to write a readonly database

Problem:

• Aufrufe der Seite die die Datenbank benutzen, wirft den Fehler "attempt to write a readonly database"

Lösung:

• die Datenbankdatei muss 664 als Rechtemaske haben
• das Verzeichnis muss dem Apache User und der Apache Gruppe gehören
• Die Datenbankdatei muss dem Apache User und der Apache Gruppe gehören

DisallowedHost - Invalid HTTP_HOST header

Problem:

Er wollte einfach nicht die IP erlauben

Loesung:

Es war ein tippfehler in der Allowed_Host Variable der Settings

ModuleNotFoundError: No module named 'MyProject'

Problem:

Der Apache schmeisst einen 500 Internal Server Error. Die Logs sagen:

ModuleNotFoundError: No module named 'MyProject'

Failed to exec Python script file '/PATH/MyProject/wsgi.py'.

mod_wsgi (pid=4996): Exception occurred processing WSGI script '/PATH/MyProject/wsgi.py'.

Traceback (most recent call last):

 File "/PATH/MyProject/wsgi.py", line 16, in <module>

application = get_wsgi_application()

 File "/PATH/site-packages/django/core/wsgi.py", line 12, in get_wsgi_application

 django.setup(set_prefix=False)

File "/PATH/site-packages/django/__init__.py", line 19, in setup

configure_logging(settings.LOGGING_CONFIG, settings.LOGGING)

File "/PATH/site-packages/django/conf/__init__.py", line 82, in __getattr__

self._setup(name)

File "/PATH/django/conf/__init__.py", line 69, in _setup

self._wrapped = Settings(settings_module)

File "/PATH/site-packages/django/conf/__init__.py", line 170, in __init__

mod = importlib.import_module(self.SETTINGS_MODULE)

File "/usr/lib/python3.7/importlib/__init__.py", line 127, in import_module

return _bootstrap._gcd_import(name[level:], package, level)

File "<frozen importlib._bootstrap>", line 1006, in _gcd_import

 File "<frozen importlib._bootstrap>", line 983, in _find_and_load

File "<frozen importlib._bootstrap>", line 953, in _find_and_load_unlocked

File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed

File "<frozen importlib._bootstrap>", line 1006, in _gcd_import

File "<frozen importlib._bootstrap>", line 983, in _find_and_load

File "<frozen importlib._bootstrap>", line 965, in _find_and_load_unlocked

ModuleNotFoundError: No module named 'MyProject'

Loesung:

In der wsgi.py nen import und nen Pfad hinzufuegen...

import sys

sys.path.append('/PATH/MyProject')