Expanding on this question I am trying to deploy Django on OpenShift but I'm having some problems understanding OpenShift.
I have managed to get as far as setting up a quick app with the git repo https://github.com/openshift/django-example but have the following questions:
Can I develop locally after git cloning to my local? (virtualenv, adding packages)
Packages, what's the deal? local, remote, adding, sycing, virtualenv, git, ...
I came across this line in Nate Aune's PaaS Bakeoff (slide 42) for setup.py and it looks quite useful:
install_requires=open('%s/project.txt' % \
os.environ.get('OPENSHIFT_REPO_DIR', PROJECT_ROOT)).readlines(),
(because I know I can pip freeze > requirments.txt in my virtualenv)
... Is %s/project.txt in wsgi or tthe directory below wsgi? Do I have to set PROJECT_ROOT with some funky os stuff?
EDIT
Basically:
Is it best to ssh into your OpenShift application (lest say you have a dev one) and work there or work off a local copy?
How do you install python packages after you have ssh'ed in to your OpenShift app? (virtualenv)
If you ssh'ed into your OpenShift app do you have to do anything after: creating a project, creating an app (manage.py startapp ...), changing code in your django app
If local is the best option:
How do I use the example locally?
Do I need to setup a virtualenv to work locally?
How do I make sure the python packages django needs are on OpenShift?
How do I add python packages to my OpenShift version (I'm presuming git doesn't do that)
I would suggest developing in a local copy.
In my experience there is no reason to ssh in, unless if you
need to perform one-of operation (migrating databases for example)
The requirements for the openshift app are specified in the setup.py file.
install_requires=['Django>=1.6.0', 'redis>=2.0']
Locally you can of course work in a virtualenv
I was facing a similar situation and found the answer provided by Luis Masuelli to the question posted here very informative. Hope it might help you.
Related
I'm working on creating my first "real" web app using Django.
Yesterday I learned I should be using a web server like Nginx to serve static files and pass off requests for dynamic content to my web app. I also learned that I need something like Gunicorn as the intermediary between the web server (Nginx) and my Django app.
My question is about virtualenv. It makes sense that we would contain app related software in it's own separate environment. What should I install in virtualenv, and what gets installed system wide? For example, in this guide we seem to install Python, Nginx and the database system wide (because they're installed before virtualenv is installed) while Django and Gunicorn are installed in virtualenv. It makes sense that Gunicorn would have to go in the virtualenv since its importing our python app, as explained here. Are the other things required to be installed system wide? Or can I pick either way? Is one way preferred over another?
Thanks!
Virtualenv is for managing Python libraries. It is not for managing Python itself, or for external services such as databases; it does however manage the Python libraries you use to access the database.
There's no room for confusion here, because there's simply no way to install Python itself or a database within a virtualenv.
I'm wondering what steps are evolved in moving a django project to a new server.
basicly i'm completely new to Django and have a few questions. The server it is on is now is not stable so I need to act fast. I did not build the app that is there but have pulled down the www folder from the root server. The server is running centOS.
Questions.
is Django backwards compatible or will I need to insure that the same version is installed?
Apart from moving the files what other steps are involved in running the app?
Will I need to use centOS or will any linux server do?
I have a database cluster of PostgreSQL ready to go also.
Start with the docs here - this will give you a good overview.
To your specific questions:
1/ Django is not backwards compatible. You should install 1.6.x. Likely, there's a requirements.txt file in the root directory of your app. On your new server, install pip and then pip install -r requirements.txt will install your dependencies. I would personally use virtualenvwrapper to manage your dependencies on the server
2/ Check the docs, but the main steps are:
Choose a web server. I personally use nginx. You'll need to setup your nginx.conf.
Choose a Python WSGI HTTP Server - I use gunicorn. You'll also need to configure this. This tutorial is a great place to start.
If you use the DigitalOcean tutorial above, any linux server will do. Last, you'll need to upload your Postgres database to the server but sounds like you're able to do that.
3/ You will need to edit your settings.py of the Django project and update certain variables.
If you're changing your database, as well as the app deployment, you'll need to edit the database connection, run ./manage.py syncdb and ./manage.py migrate (if you're using South) to set up the database schema.
It's also recommended to change the SECRET_KEY between deployments.
If you're deploying on a different hosts, you'll need to edit ALLOWED_HOSTS appropriately for your new deployment as well.
Good luck!
I have my development environment setup on Win 7 like this:
Django development structure
Apache -server- C:\Program Files (x86)\Apache Software Foundation\Apache2.4
PostgreSQL -database- C:\Program Files\PostgreSQL\9.2
Django -framework- C:\Python27\Lib\site-packages\django
Python -code- C:\Python27
Project -root- C:\mysite
|----------apps
|----------HTML
|----------CSS
|----------JavaScript
|----------assets
I am attempting to keep this extremely simple to start out. There are 5 main directories each with a distinct purpose. All the code resides in the project folder.
compared to WAMP structure:
C:\WAMP
|----------C:\Apache
|----------C:\MySQL
|----------C:\PHP
|----------C:\www
I like how Apache, MySQL, and PHP all reside in a neat directory. I know to keep the root project OUTSIDE in another directory in Django for security reasons.
Is it fine that Apache, PostgreSQL, and Python are installed all over the place in the Django environment?
Did I miss a core Django component and/or directory?
Will deploying and scaling be a problem?
I want this to be a guideline for beginning Django web programmers.
I can answer the question one by one:
Is if fine that Apache, PostgreSQL, and Python are installed all over the place in the Django environment?
All over the place sounds weird but yes it is totally fine.
Did I miss a core Django component and/or directory?
No you don't miss anything, Django core is in site-packages folder already and your site code is mysite, which can be located anywhere you want.
Will deploying and scaling be a problem?
No it won't be a problem with current structure. You will deploy your mysite only, the other will be installed separately.
Something you should get familiar with when starting with Django development:
Most likely when you deploy your project, it will be on a Linux server, so install and learn Linux maybe?
virtualenv: Soon you will have to install Django, then a bunch of external packages to support your project. virtualenv helps you isolate your working environment. Well it's "unofficial" a must when you start with python development.
virtualenvwrapper to make your life easier when working with virtualenv
git and github or bitbucket: if you don't know git yet, you should now.
Apache is just web server, it is used to serve files, but to make a website you do not necessary need it. Django comes with its own development server. See :
python manage.py runserver
Apache is required when you are developing PHP websites because your computer do not know how to compile and interpret it. But for Django, you use the Python language, and you have already install it if you are using Django.
Read https://docs.djangoproject.com/en/1.5/intro/tutorial01/
And where it will be the time to set up your own server using Apache look at :
https://docs.djangoproject.com/en/dev/howto/deployment/wsgi/modwsgi/.
Scaling will be a problem on windows. Python in Apache on windows gets 64 threads in one process. Couple this with the GIL and you will have scaling issues.
Python and Apache on Linux don't have this same problem. Under Linux wsgi can create multiple processes that have multiple threads each, minimizing GIL issues.
WSGI in Apache on windows is not a scalable solution in my opinion.
However you can develop there and move to linux for deployment, I do it all the time.
You will want to take advantage of the Apache Alias directive to serve all your static content like css, js, favicon.ico. This frees up python to only handle requests that require logic.
I'm writing a Python Flask app to deploy on Heroku. It will use a database. For local development, I'd like to use Sqlite, but when deployed to Heroku I'd like to use Postgresql. How can I achieve this?
I'm stuck because I don't know how to require a different set of packages between my box and the Heroku server.
Were this a Ruby app I would write in my Gemfile
gem "pg", :group => :production
gem "sqlite3", :group => :development
Then Bundler would install the appropriate packages in development and in production. But I don't know any analogous workflow for Python's pip
Well, you have two things to solve.
First, the requirements.txt which isn't that much of a problem. You can either throw all the requirements in the same requirements.txt file, having both database bindings installed doesn't harm anything. If you want to separate, however, just use requirements.txt for deploying, and requirements-dev.txt for local development.
More important is the DB settings itself, and for that you have a one liner solution:
app.config['SQLALCHEMY_DATABASE_URI'] = os.environ.get(
'DATABASE_URL', 'sqlite:////tmp/test.db')
Since DATABASE_URL is set on Heroku, but not on local (make sure this is the case), os.environ.get will not find it, thus reverting to the default, which is the sqlite connection string .
I have tried following guides like this one but it just didnt work for me.
So my question is this: What is a good guide for deploying Django, and how do you deploy your Django.
I keep hearing that capastrano is pretty nifty to use, but i have no idea as to how to work it or what it does (apart from automation of deploying code), or even if i want/need to use it or not.
mod_wsgi in combination with a virtualenv for all the dependencies, a mercurial checkout into the virtualenv and a fabric recipe to check out the changes on the server.
I wrote an article about my usual workflow: Deploying Python Web Applications. Hope that helps.
I have had success with mod_wsgi
In my previous work we had real genius guy on deployment duties, he deployed application (Python, SQL, Perl and Java code) as set of deb files built for Ubuntu. Unfortunately now, I have no such support. We are deploying apps manually to virtualenv-ed environments with separate nginx configs for FastCGI. We use paver to deploy to remote servers. It's painful, but it works.
This looks like a good place to start: http://www.unessa.net/en/hoyci/2007/06/using-capistrano-deploy-django-apps/
I use mod_python, and have every site in a git repository with the following subdirs:
mysite
template
media
I have mysite/settings.py in .gitignore, and work like this:
do development on my local machine
create remote repository on webserver
push my changes to webserver repo
set up apache vhost config file, tweak live server settings.py
run git checkout && git reset --hard && sudo /etc/init.d/apache2 restart on webserver repo to get up-to-date version to its working copy and restart apache
repeat steps 1, 3 and 5 whenever change request comes
The easiest way would be to use one of the sites on http://djangofriendly.com/hosts/ that will provide the hosting and set up for you, but even if you're wanting to roll your own it will allow you to see what set up other sites are using.